# The CAD/CAM unit in Paris Descartes University: for and by students.

Anne-Margaux Collignon, Claudine Wulfman, Jakubowicz Boris, Mathieu Derbanne, Zamansky Bruno, Nicolas Lebon, Dubroca Aurélie, Laurent Tapie, Jean-Pierre Attal

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## ► To cite this version:

Anne-Margaux Collignon, Claudine Wulfman, Jakubowicz Boris, Mathieu Derbanne, Zamansky Bruno, et al.. The CAD/CAM unit in Paris Descartes University: for and by students.. ConsEuro Conference 2015, May 2015, Londres, United Kingdom. 19, pp.1701-1754, 2015, 10.1007/s00784-015-1486-4 . hal-02090801

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ABSTRACTS

ConsEuro Conference 2015, London, May 14-16

The bi-annual ConsEuro Conference 2015 was recently held in London at the Queen Elizabeth II conference centre, Westminster. The conference was hosted by Professor Stephen Dunne, President of the European Federation of Conservative Dentistry (EFCD) and was a joint meeting of the EFCD, British Society for Restorative Dentistry, Association of Teachers of Conservative Dentistry and King's College London.

The theme of the conference was Technology in Dentistry and in keeping with that theme, the conference was as near paperless as possible. The conference proved a great success with over 500 delegates attending, from 29 different countries, from as far afield as India, Australia, Senegal, USA and, of course, from right across Europe.

Over 40 lecturers and demonstrators from around the world present-
ed a truly international view and covered the full range of technol-
ogies in dentistry. The programme also included ancillary meetings,
lectures and demonstrations including the Academy of Operative
Dentistry, European Section, sponsored by DMG and separate meet-
ings organised and sponsored by Kuraray, Colgate, Unilever, the
BDJ, 3M ESPE and Henry Schein. The conference received extraor-
dinary support from the dental industry, the Gold Sponsors were
Colgate, 3M ESPE, Kuraray and Unilever. The Silver Sponsors
were Dentsply, Dentinal Tubules, Septodont, and Ivoclar Vivadent,
while the Bronze Sponsors were Henry Schein and Planmeca. Ex-
hibitors included ARC Laser, Dentists Provident, GC, the BDJ,
Quintessence Publishing and NS.

Professor Dunne expressed his gratitude to the dental industry for their generosity and also to the ConsEuro Conference Committee, in particular to Mr Leslie Howe, Professor Avi Banerji, and Mr Jim Lucas of Hampton Medical, our Professional Conference Organiser, for their tireless efforts in organising this conference.

ConsEuro 2017 will be held in Italy and the EFCD look forward to
welcoming you.

Professor Stephen Dunne
President of the EFCD

Poster Abstracts Accepted for Publication at ConsEuro 2015, London

Please note the abstracts have been divided in categories utilising the
following abbreviations:

• Biomaterials (BM);

• Clinical Cases (CC);

• Dental Education (DE);

• Endodontics & Pulp Biology (EP);

• Preventive Dentistry (PD);

• Operative Dentistry (OD);

Biomaterials (BM)

BM01

Laboratory evaluation of tooth dissolution in cough syrups

Cornelius Bamise, Temitope Esan, Elizabeth Oziegbe, Francis Alo
*Obafemi Awolowo University, Ile Ife, Osun State, Nigeria*

**Background:** Currently, the increased consumption of acidic foods and medications is becoming an important factor for the development of erosive wear because of their acidic nature. Therefore, most clinical and laboratory researches have focused on their dental impact.

**Aim.** To evaluate the associated weight loss of extracted teeth after immersion in cough syrups for a period of time.

**Materials and Methods.** pHs of the medicines were measured at the start of the study.

25 extracted test teeth were weighed to 0.01 mg and assigned at random to each syrup under evaluation. The test medicines were placed in 10 mL screw-cap plastic containers and the test teeth were weighed after 7 days.

**Result.** 88 % of the medicines caused reduction in weights of the test teeth after seven days of immersion. Weight loss of the test teeth also noticed with basic syrups. Also lowest pH syrup did not produce the greatest weight loss.

**Conclusion:** Majority of the cough syrups caused loss of weight of the test teeth. Thus, they possess the potential to cause dental erosion.

BM02

Quantification of the amount of blue light passing through
monolithic zirconia

Nicoleta Ilie¹, Bogna Stawarczyk²

¹Dental School, Ludwig-Maximilians University, 1Department of Operative/Restorative Dentistry, Periodontology and Pedodontics, Munich, Germany, ²Dental School, Ludwig-Maximilians University, 2Department of Prosthodontics, Munich, Germany

Dual-polymerized luting composite resin cements would benefit from an
enhanced irradiance transmitted through a ceramic restoration. A quanti-
fication of the amount of transmitted light through translucent zirconia is
missing so far. It was the purpose of this study to evaluate the amount of
light (360 to 540 nm) passing diverse ceramic materials with respect to
material thickness and different polymerizing modes and to identify ma-
terial parameters allowing calculation of the amount of transmitted irra-
diance at any initial irradiance or material thickness.

Six translucent and a conventional zirconia (negative control) as well as a
glass-ceramic (positive control group) were considered. Ten specimens of
each material and thickness (0.5; 1; 1.5; 2; 2.5; 3 mm) were fabricated (N
= 480). The irradiance passing the different ceramics and thicknesses was measured using a violet-blue LED polymerizing unit in three polymerizing modes with a USB4000 Spectrometer. Data were analyzed using one and multivariate analysis as well as Pearson correlation analysis (p < 0.05). Zirconia was less translucent compared to the glass-ceramic, but the translucency decreased more slowly with material thickness, thus approaching the translucency of glass-ceramics at specimen thicknesses of 2.5 to 3 mm.

The decrease of transmitted irradiance with increased specimen's thickness was well described by the Beer-Lambert law in all materials. The derivative of this equation allows determination of the velocity of translucency decrease as a function of thickness. The determined equation parameters allow calculation of the amount of transmitted irradiance for the analysed materials at any initial irradiance or material thickness.

## BM03

### Effect of MTA setting time intervals on its shear bond strength with overlying restorative materials.

Ahmed Ali, Avijit Banerjee, Francesco Mannocci

King's College London, London, UK

**Objective:** in-vitro comparison of shear bond strength (SBS) and interface failure modes (IFM) between mineralised trioxide aggregate (MTA) and glass ionomer cement (GIC) or resin composite (RC) after different setting time intervals for MTA.

**Materials and Method:** MTA was mixed and packed into standardised holes (4 X 3mm) in acrylic blocks. RC (with 37% $H_3PO_4$ and type 2 adhesive used per manufacturer's instructions) or GIC were bonded to MTA specimens either after 10min, 24hrs and 72hrs intervals (n = 10/group, 6 groups). All groups were stored (37C°, 24 hrs) before testing. SBS was tested (0.5mm/m) and statistically analysed (ANOVA, LSD, *p* < 0.05). IFM were identified using stereomicroscopy and SEM images of three samples were analysed.

**Results:** There was a significant difference between all groups (p = 0.003). SBS of RC to MTA (5.09 ± 1.79 MPa) was higher than SBS of GIC to MTA (2.77 ± 1.05 MPa). There was significant increase in SBS of RC to MTA with time except in 10min setting time groups, where SBS of GIC to MTA was higher. IFM were mixed (adhesive and cohesive) in all groups but in RC-MTA groups there was decrease in adhesive trend with time in contrast to GIC-MTA groups.

**Conclusion:** Shear bond strengths between RC and MTA was significantly higher than that of GIC and MTA after 24 and 72 hours' time intervals of MTA setting time.

**Clinical relevance:** If a vital pulp therapy treatment in one session is to be considered it will be feasible to use GIC over unset MTA before placement of a RC.

## BM04

### Influence of tetracalcium-phosphate (TTCP) and calcium-phosphate acid (DCPA) on bond-strength of self-etch adhesives

Allegra Comba<fnref n="1" />, Mattia Chiapello<fnref n="1" />, Lorenzo Breschi², Gianluca Turco<fnref n="3" />,
Elio Berutti<fnref n="1" />, Nicola Scotti<fnref n="1" />

**Objective:** The aim of this in-vitro study was to evaluate the influence of a dentinal pre-treatment with TTCP and DCPA on the bond-strength of 2 adhesive systems employed with the etch-and-dry technique. The null hypothesis are that the application of synthetic hydroxyapatite over dentin (1) is not able to influence bond strength of adhesives applied following an etch-and-dry approach and (2) it does not prevent adhesive interface degradation.

**Methods:** 60 molars crowns were flattened and standardized smear layer was created. Samples were randomly divided in 6 groups:

G1 2-step self-etch adhesive (Clearfil Protect Bond, Kuraray) application

G2 TeethMate Desensitizer (Kuraray), water rinse for 10 seconds and the 2-step self-etch adhesive application

G3 10%EDTA for 30 seconds, air drying and TeethMate Desensitizer and 2-step adhesive application

G4 universal adhesive (All Bond Universal, Bisco) application

G5 TeethMate Desensitizer, water rinse for 10 seconds and universal adhesive application

G6 10%EDTA for 30 seconds, air drying and TeethMate Desensitizer and universal adhesive application

Then resin composite was applied. Specimens were serially sectioned to obtain 1-mm-thick beams in accordance with the µTBS test technique. Beams were stressed to failure after 24h, 6 and 12 months of storage in artificial buffer at 37 C.

**Results:** Three-way Anova showed that adhesive system, treatment protocol and aging are influencing factors (p < 0.0001), but not their interactions.

**Conclusion:** Null hypothesis are partially refused since the application of TTCP and DCPA is able to improve bond strength values and degradation overtime only if employed in combination with dentin pre-treatment with 10%EDTA.

## BM05

### The effect of MMP-inhibitor modified adhesive primer on the caries-affected dentine: A Raman spectroscopy study

Ahmed Almahdy<fnref n="1" />,², Garrit Koller<fnref n="1" />, Frederic Festy<fnref n="1" />, Jörg Bartsch<fnref n="1" />,<fnref n="3" />,
Timothy F. Watson<fnref n="1" />, Avijit Banerjee<fnref n="1" />

¹Dental Institute, King's College London, London, UK, ²College of Dentistry, King Saud University, Riyadh, Saudi Arabia, ³University of Marburg, Marburg, Germany

**Objectives:** To evaluate the effect of adding a matrix metalloproteinase (MMP) inhibitor (BB94) to the primer of a three-step etch and rinse adhesive system on the chemical content of the caries-affected dentine (CaD)-adhesive interface.

**Methods:** Caries-infected dentine (CiD) was excavated selectively from five freshly extracted human carious teeth using a chemo-mechanical agent. Each tooth was sectioned into three slabs. These were treated with either Optibond FL “OB” (Kerr, Orange, USA) without MMP inhibitor, or with 500µM BB94 prior to the application of OB primer and bond, or with OB primer that contained 5µM BB94. Raman micro-spectroscopy

<footnote n="1">¹University of Turin, Turin, Italy, ²Alma Mater Studiorum, Bologna, Italy,</footnote>

<footnote n="3">³University of Trieste, Trieste, Italy</footnote>
(Renishaw Plc, Wotton-under-Edge, UK) was used to investigate the changes in the chemical content at the CaD-adhesive interface. The interface areas were scanned immediately (week 0), after two weeks (week 2) and after one month (week 4). Pearson-based cluster analysis of the dataset (over 1.8 million spectra) was performed. The average cluster content within the hybrid layer layer was calculated for all groups. Two-way ANOVA and Tukey's post-hoc test were used to compare the differences in the relative contribution of each cluster between the three groups at the three different times.

**Results:** The use of OB adhesive with BB94 resulted in 33% higher resin infiltration into CaD-adhesive interfaces (SE 3.88). This was maintained over time.

**Significance:** Through competitive inhibition by BB94, the adhesive primer was brought close to the collagen matrix and the dental adhesive wettability was enhanced. This proposed mechanism explains the presence of more resin within the hybrid layer.

## BM06

### Evaluation of hardness increase of GIC restorative surface in saliva.

Yusuke Shimada, Yusuke Hokii, Katsushi Yamamoto, Shouichi Fukushima, Tomohiro Kumagai
GC Corporation R & D centre, Tokyo, Japan

**Objective:** Increasing of surface hardness of GIC in saliva is one of unique phenomenon. The aim of this study was to evaluate the surface hardness of new experimental GI filling system.

**Methods:** Experimental system consists of experimental GI filling material, EFI-300 and experimental surface coating material, EQC-107. EFI-300 and Fuji IX GP EXTRA (F9E) were filled into acrylic mold (7 mm in diameter, 2 mm in depth). Specimens were then stored at 37°C, 100%R.H. for 1 hour. Specimens were then stored as follows under 37°C, EWC: EFI-300 with EQC-107 in water. ESC: EFI-300 with EQC-107 in saliva. EW: EFI-300 in water. ES: EFI-300 in saliva. XWC: F9E with G-Coat Plus (GCP) in water. XSC: F9E with GCP in saliva. XW: F9E in water. ES: F9E in saliva. After 0, 30 and 65days, surface hardness of specimens were measured with micro vickers hardness machine (SHIMADZU: HMV-G21DT). Coatings were removed from GI surface before measuring vickers hardness. Specimens were recoated before immersion to storage from 0 to 30 days. After 30days, all specimens were immersed in the solutions without coatings.

**Result:** Results of 30days are ESC(121HV), XSC(106), EWC(117), XWC(126), ES(116), XS(115), EW(105), XW(106), and 65 days are ESC(141HV), XSC(139), EWC(118), XWC(116), ES(127), XS(129), EW(105), XW(92).

**Conclusion:** These results indicate that new experimental GI filling system also increases in surface hardness in saliva.

## BM07

### Comparison of Mechanical Properties of Composite with Different Enamel Shades

Zeynep Bilge Kutuk¹, Sevil Gurgan¹, Reinhard Hickel², Nicoleta Ilie²

¹Hacettepe University Faculty of Dentistry Restorative Dentistry Department, Ankara, Turkey, ²Ludwig Maximilians University, School of Dentistry, Department of Restorative Dentistry and Periodontology, Munich, Germany

**Objective:** To compare the macro- and micro-mechanical properties of a highly translucent composite with different enamel shades.

**Materials and methods:** Three different enamel shades of a highly translucent composite were used (G-aenial Anterior SE, AE and JE). The specimens (n = 20) were prepared by a steel mould having an internal dimension of 2 × 2 × 16mm. Irradiation was occurred on top and at the bottom of the specimens, with three light exposures of 20s per side. The specimens were ground with silicon carbide sand papers (1200/4000), then stored in distilled water at 37°C for 24 h. The specimens were loaded until failure in the universal testing machine in a three-point bending test device to determine flexural strength and flexural modulus. Micromechanical properties -Vickers hardness (HV), indentation modulus (E) and creep (Cr) were examined by a universal hardness device. Six measurements per specimen, 60 measurements for each material were done. Results were statistically compared using one-way ANOVA and Tukey's HSD post hoc test (α = 0.05).

**Results:** Among the three different enamel shades, SE which mimics elderly people enamel shade showed the lowest values for all mechanical properties. Conversely, JE shade, suitable for young patients, showed the highest flexural strength, flexural modulus, E and Cr values. Nevertheless, no significant differences were found between the macro- and micro-mechanical properties of the composites with different enamel shades (p > 0.05).

**Conclusion:** Differences in enamel shades did not affect the mechanical properties of highly translucent composites.

## BM08

### The Effect of Different Storage Mediums on Dentin Moisture, Microhardness and Bonding

Aysegul Kaya¹, Tijen Pamir¹, Pinar Kosker¹, Bilge Hakan Sen²

¹Ege University School of Dentistry, Izmir / Bornova, Turkey, ²izmir Katip Çelebi University School of Dentistry, Izmir / Cigli, Turkey

**Purpose:** This study was aimed to observe the effect of different storage mediums on dentin moisture and microhardness in addition to the bond strength of a resin composite to dentin.

**Methods:** 30 human non-carious pre-molars were used. After extraction, each 10 teeth group was kept in % 0.1 tyhmol, distilled water or dry storage for 7 days at room temperature. After sectioning of all teeth in longitudinally, enamel of the samples was removed. Vestibular parts of the samples were used for dentin moisture which were determined by grain moisture meter(M recieter 480, Japan). Following the dentin micro-hardness, microshear bond strength were measured on lingual dentin parts of the samples. The flowable resin composite cylinders(SDR, Dentsply, USA). in 0.9 mm diameter and 3 mm high were bonded to dentin using a self-etching adhesive(Clearfil SE Bond, Japan). Universal testing machine was used bond strength measurements.

**Results:** Moisture measurements of the dentin samples which were preserved various storage mediums presented significant differences (p < 0.05). Similarly, storage mediums affected bonding strength of the resin composite to dentin (p < 0.05). The highest dentin bond strength were obtained when distilled water was used for storage solution (p < 0.05). However, microhardness measurements were not affected from different storage conditions (p > 0.05).
**Conclusions:** Within the limitations of this study, it was concluded that different storage mediums affected the dentin moistures and microshear bond strength test results except for microhardness.

**Keywords:** Dentin, Moisture, Storage medium, Micro-hardness, Micro-shear bond strength

BM09

**Randomised crossover-controlled trial investigating poly-ether-ether-ketone (PEEK) materials in tooth-and-mucosa supported RPDs - Preliminary report.**

Zaid Ali¹,², Nicolas Martin¹,², Sarah Baker¹

¹University of Sheffield, Sheffield, UK, ²Charles Clifford Dental Hospital, Sheffield, UK

**Introduction:** Poly-aryl-ether-ketone (PAEK) materials are marketed as non-metal alternatives for prosthodontic frameworks increasing the range of materials to consider when prescribing fixed and removable restorations. Despite the advantages of bone-mimicking modulus of elasticity, low weight to strength ratio, and biocompatibility from years of use as an orthopaedic device material, the introduction into the dental market has been a relatively recent development. Current evidence regarding the clinical use of these materials is limited to case reports and case series. The aim of this EPSRC funded randomised crossover-controlled clinical trial is to explore the differences between the use of poly-ether-ether-ketone (PEEK) framework removable partial dentures (RPDs) and traditional cobalt chromium (CoCr) framework RPDs on oral health-related quality of life (OHRQoL), health-related quality of life (HRQoL) and gingival health.

**Methods:** In this pilot study twelve patients with a minimum of four missing teeth per dental arch (excluding third molars) have been provided with either CoCr or PEEK framework RPDs to wear for four weeks. Outcome measures in this pilot study are impact on OHRQoL measured by OHIP-20, HRQoL measured by the SF-12v2.0 and clinical outcomes including plaque index, bleeding on probing, tooth mobility and peri-odontal pocketing. After the first four weeks patients will be given the other denture to wear for a second four week period before outcome measures are repeated.

**Preliminary Results:** We present the results for the first twelve participants to be recruited to this pilot study.

BM10

**Comparative study of the photo-polymerization depth of flow composite materials using Raman microscopy**

Sebastiana Arroyo Bote, Javier Martinez Osorio, Esther Berastegui Jimeno

Faculty of Dentistry. Barcelona University, Barcelona, Spain

**Objective:** The aim of this study is to evaluate the depth of photo-polymerization of different composite materials whose indications are Cavitary base flow in comparation with conventional flow hybrid composites.

**Materials and Methods:**

We have selected four Cavitary base flow materials (A) and four conventional flow hybrid composites (B).

GROUP A:

1. SDR TM (Dentsply)

2. Xtra base (VOCO)

3. Vertiseflow (Kerr)

4. everX Posterior + IFU (GC)

GROUP B:

6. X-Flow (Dentsply)

7. Grandioso flow (VOCO)

8. Premise flowable (Kerr)

9. G-aenial universal Flow (GC)

For photo-polymerization have been selected Demi Plus LED Dental Curing Light 1100 mW/cm2 (KERR).

We have prepared ten samples for each material, in cylinders of 3,5mm of diameter and 10 mm of height. Ever cylinder was polymerized during 10 seconds. The polymerized cylinders have been studied by microscopy Raman analyzing the spectra of the material along the height of the cylinders, realizing measurements every 100 microns.

**Results:** The results demonstrate the differences between the eight materials. The statistical study with no parametric probe (Kruskal-Wallis), revealed significant differences between the results obtained from the two groups (A-B), the best results were from the group A. We also found significant differences in the depth of the polymerization between the four materials that we analyzed in group A,(U of Mann-Whitney). The most successful results were EverX Posterior.

**Conclusion:** The polymerization carried out with the high intensity lamp for 10 seconds, was lower for Cavitary base flow group in comparation with conventional flow hybrid composite.

BM11

**Fatigue Testing of Ultrathin Occlusal Veneers**

Karl-Heinz Kunzelmann¹, Peter Rösch², Helena Schäfer¹

¹LMU-München, Operative Dentistry, Munich, Germany, ²Univ. Applied Sciences, Augsburg, Computer Science, Augsburg, Germany

**Introduction:** Occlusal veneers (OV) are a conservative alternative during the treatment of occlusal erosions in order to reestablish the original occlusal height and protect the tooth from further occlusal tissue loss. While traditionally a ceramic thickness of 1.5 mm is recommended by the manufactures for occlusally loaded ceramic restoration material improvements make a reevaluation of this recommendation necessary.

**Materials and Methods:** The teeth were anatomically reduced so that dentin was exposed on the whole occlusal surface and ultra-thin OV were manufactured with defined thickness using a CEREC CAD/CAM machine. The thickness of the OV was 0.5-
0.8 mm. 20 samples of each material (Vivadent: IPSEmpressCAD, IPSe.maxCad, 3M/ESPE: LavaUltimate) were adhesively luted with Variolink II after pretreatment of the tooth surface with Syntac Classic (total-etch). The restorative materials were pretreated according to manufacturer's recommendations. The teeth were fatigue loaded in a fatigue simulator for 10^6 cycles with 50 N/cycle. Every decade the damage was investigated. As soon as a crack was visible with lateral illumination the sample was considered to be a loss.

**Results:** The cumulative survival probability (Kaplan-Meier) was: Empress 0.5 (9 losses after 10^4 cycles, 1 after 10^5 cycles), E.max 1.0, LavaUltimate 0.95 (1 loss after 10^5 cycles). The 95% CI suggests a significant difference between Empress and E.max/ LavaUltimate, while no difference was obvious between E.max and LavaUltimate.

**Conclusions:** Based on the high-cycle fatigue simulation and the rigorous failure criterion the modern materials E.max and LavaUltimate should be a feasible alternative for the treatment of occlusal erosions with ultrathin occlusal veneers.

## BM12

### Finite Element Analysis of Ultrathin Occlusal Veneers

Peter Rösch¹, Karl-Heinz Kunzelmann²

¹Augsburg University of Applied Sciences, Faculty of Computer Science, Augsburg, Germany, ²Ludwigs-Maximilians University, Munich, Dept. of Restorative Dentistry and Periodontology, Munich, Germany

**Introduction:** In order to systematically develop ultrathin occlusal veneers, an experimental fatigue simulation has been complemented with a finite element analysis (FEA) based on micro CT images of the very same specimen. A quantitative comparison of different materials and geometries requires configurable software allowing for semi automatic volumetric analysis and visualisation.

**Materials and Methods:** Extracted teeth with ultrathin occlusal veneers were imaged using a Scanco Micro-CT 40 device. The 3D images (isotropic resolution: 0.04 mm) were segmented with ImageJ and itk-SNAP. Orchestrated by a configurable python script, tetrahedral meshing and linear FEA were performed using iso2mesh and z88 with Young's moduli of 95.0, 84.1, 18.6 and 5.0 GPa for ceramic, enamel, dentine and glue respectively. Mimicking experimental conditions, a distributed surface load of 100 N was applied to restored cusps. For a comparison with resin nano ceramic materials, FEA was repeated with a modulus of 13.0 GPa for the restoration. Results were visualised and statistically analysed with ParaView and numpy.

**Results:** Plausibility of results could be verified by visual inspection. Statistical analysis of volume weighted maximum principle stress values within the restoration based on about 200000 tetrahedra yields the following percentiles: Median: 0.30 (0.066) GPa, P(0.9): 2.0 (0.57) GPa, P(0.99): 5.8 (4.3) GPa and P(0.999): 8.7 (5.5) GPa where stress values in brackets correspond to nano ceramic material.

**Conclusions:** Based on free software, a tool chain for FEA has been established and successfully applied to ultrathin occlusal veneers. The study will be extended to a larger number of samples.

## BM13

### Bonding of a CPP-ACP containing glass ionomer cement to human enamel, sound-, and caries-affected dentine

Michael Burrow¹, Hiroyasu Koizumi², Hamdi Hamama³

¹University of Melbourne, Melbourne, Australia, ²Nihon University, Tokyo, Japan, ³Mansoura University, Mansoura, Egypt

Glass ionomer cements are regarded as one of the few materials that reliably bond to enamel and dentine as well as assist with inhibition of dental caries. To aid caries inhibition and remineralisation of early lesions, casein phosphopeptide amorphous calcium phosphate (CPP-ACP) has been incorporated into Fuji VII (Fuji Triage). Previous laboratory work has shown the addition of CPP-ACP reduces enamel demineralisation.

The purpose of this study was to evaluate the microtensile bond strength of a conventional and the CPP-ACP containing glass-ionomer cement (GICs) to human enamel, sound-, and caries-affected dentine (CAD). Twenty non-carious teeth and 10 teeth exhibiting frank dentine caries lesions (human molars) were used. A conventional GIC (Fuji VII, GC Corporation, Japan) or CPP-ACP-modified GIC (Fuji VII EP, GC Corp) were used as the test materials. Microtensile bond strengths were measured and analyzed statistically using two-way ANOVA at α = 0.05. The morphology of bonded interfaces were observed with SEM.

The results of the two-way ANOVA showed that the bond strength was not significantly affected by the type of 'GICs' (p = 0.183, >0.05) and 'teeth substrates' (p = 0.390, >0.05). Furthermore, the interaction between 'GICs' and 'teeth substrates' was also not significant (p = 0.349, >0.05). Mean bond strengths of the Fuji VII was 3.8 MPa for enamel, 5.3 MPa for sound-dentine, and 5.0 MPa for CAD, and Fuji VII EP was 5.4 MPa for enamel, 5.4 MPa for sound-dentine, and 5.1 MPa for CAD. The results demonstrated that the adhesion of CPP-ACP containing GIC was no different to that of the conventional GIC.

## BM14

### Effect of a cavity cleanser/desensitizing agent on bond strengths

Hiroyasu Koizumi¹,⁴, Michael Burrow², Hamdi Hamama³

¹Nihon University School of Dentistry, Tokyo, Japan, ²University of Melbourne, Melbourne, Australia, ³Mansoura University, Mansoura, Egypt, ⁴The University of Hong Kong, Hong Kong, Hong Kong

Recently a silver diamine fluoride and potassium iodide solution (Riva Star) has been introduced for clinical use as a desensitizing agent or biofilm inhibitor. Little is known whether bond strengths are affected by application of this material.

The aim of this study was to determine whether Riva Star influenced bond strengths to an etch and rinse (Optibond FL), 2-step self-etching (Clearfil Liner Bond F) and all-in-one (Optibond Versa) resin-based adhesive and a resin-modified GIC adhesive (Riva Bond LC).

Human mid-coronal dentine was the substrate used. The adhesives were bonded according to the manufacturers' instructions or after the dentine surfaces had been treated with the Riva Star. Teeth were sectioned into 1 mm X 1mm samples and subjected to a microtensile bond strength test. Results were analysed using univariate analysis of variance and Sidak's multiple test.
It was shown bond strengths were adversely affected for all adhesives. Control: Optibond FL 32.1 MPa, Clearfil Liner Bond F 28.4 MPa, Optibond Versa 35.0, Riva Bond LC 18.4 MPa; Riva Star treated groups: Optibond FL 21.4 MPa, Clearfil Liner Bond F 10.8 MPa, Optibond Versa 9.6 MPa, Riva Bond LC 14.5 MPa.

Only the GIC and etch and rinse adhesive were less effected by the Riva Star application. SEM analysis showed that Riva Star left a precipitate on the dentine surface which adversely affects self-etching systems. It was concluded that Riva Star should not be recommended to cleanse cavities but used only for spot application where a cavity is close to the pulp.

## BM15

### Conversion Degree and Micro-Hardness two dual cements cured with three different protocols under Zirconia discs

Stefano Serra, Allegra Comba, Luca Fontanive, Milena Cadenaro, Elio Berutti, Nicola Scotti
*University of Turin, Department of Surgical Sciences, Turin, Italy*

**Objectives:** The aim of this *in vitro* study was to assess the conversion degree (DC) and the micro-hardness (MH) of two dual cements employed under zirconia discs and cured with three different time protocols. The null hypothesis is that different curing protocols are not able to improve DC and MH of the cement.

**Methods:** 30 Zirconia discs of 2cm of diameter were prepared. Discs were divided into two groups (n = 15) according to the cement employed: 1) Rely-X (3M, ESPE); 2) Panavia V5 (Kuraray). Each group was further divided into 3 subgroups (n = 5): a) no light; b) 20 sec cure; c) 120 sec cure. Polymerization was performed 60 sec after the sample was placed on the diamond support of a FT-IR spectrophotometer of new generation (Thermo Scientific Nicolet IS10) with a high power multiLED lamp (Valo-Ultradent). Final DC% were calculated after 10 minutes. Once the conversion degree has been established, a Vickers Test with a micro-indentometer was performed. ANOVA test was performed to find differences between DC% and HM of the two cements.

**Results:** One-way Anova showed that the two cements reached higher DC% in subgroup b) and c) (p < 0.05). Further, Rely-X showed higher DC% than Panavia2.0 only after 20sec cuing (p < 0.05). As concern MH, Anova test showed that an increase in curing time is able to improve MH significantly both for Rely-X and Panavia2.0.

**Conclusions:** The null hypothesis has to be rejected since DC% and MH of the dual cements tested were influenced by the curing time protocol.

## BM16

### Color changes of expired restorative composite resins

Nikolina Spyropoulou, Anastasia Plevritaki, Panagiotis Lagouvardos
*Dental school of Athens, National Kapodistrian university of Athens, Athens, Greece*

**Purpose:** Composite resins are not to be used after their expiration date but a number of clinicians do make restorations with such materials. Since information on the stability in staining solutions of these materials is

lacking, the purpose of this study was to evaluate the changes of expired composites within coffee as a staining solution.

**Materials and Methods:** 3 composite resins were selected from a pool of expired(X) after a significant time period, but kept in standard conditions(ice/SDI-15months, rok/SDI-89months, Spectrum/Dentsply-146months). Non expired(N) composites from the same materials were also selected and discoid specimens(2mm in thickness by 6.5mm in diameter) were made from all materials. All specimens were finished with SiC wetordry paper up to 1000 grit, polished on a velvet microcloth and stored initially for 48h in water of 37oC and then in coffee baths for 2hours, 4hours and 6hours, simulating a 30days, 60days and 90days staining effect of coffee (two daily drinks of coffee-4min/day). A mean of three measurements of color parameters in the CIELAB system were taken in all periods with a portable contact colorimeter(ShadeEye/Shiofu) and the data were analyzed statistically by 2wayANOVA at a = 0.05.

**Results:** Color difference values(ΔE*) between base line and the staining periods for the investigated materials were 4.9, 9.3, 10 for rokX, 5.2, 11.9, 13.8 for rokN, 10.8, 19.7, 29.6 for spectrumX, 17.2, 31.4, 38.8 for spectrum and 8.7, 27.9, 23.7 for iceX, 11.3, 23.9, 20.2 for iceN. 2way ANOVA indicated no differences between expired and not expired materials but significant differences between staining periods.

**Conclusions:** Although investigated materials had expired for long, their staining behavior within coffee were not different from not expired materials.

## BM17

### µTBS of an etch-and-rinse adhesive system enriched with Chlorhexidine-digluconate Loaded Nanodroplets

Stefania Rivarossa¹, Diletta Basile¹, Riccardo Tempesta¹, Marta Gai², Caterina Guiot³, Roberta Cavalli³, Elio Berutti¹, Nicola Scotti¹

¹Dental School, University of Turin, Torino, Italy, ²Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy, ³Department of Neurosciences, University of Turin, Torino, Italy

**Purpose:** Drug Loaded Nanodroplets (DLNs) could be employed for MMPs Inhibition Agents delivery and release in dentin. The aim of this in vitro study was to evaluate the influence of dentin pre-treatment with Chlorhexidine-digluconate loaded Nanodroplet (CHXLNs) on the bond strength of an etch-and-rinse adhesive system.

**Methods and Materials:** 10 molars crowns were flattened and standardized smear layer was created. Exposed dentin surfaces were etched with 36% phophoric acid for 15sec. Sample were divided in two groups according to the application (G1) or not (G2) of CHXLNs for 30sec and dried. Then, in all samples, Schotchbond Universal was applied and cured for 60sec at 1400mW with Valo. Then resin composite was applied. Specimens were serially sectioned to obtain 1-mm-thick beams in accordance with the µTBS test technique. Beams were stressed to failure after 7 days of storage in artificial buffer. Two more samples were prepared and sectioned in order to observe hybrid layer with confocal laser scanning microscopy. One-way Anova was performed to evaluate the effects of CHXLNs pre-treatment on the bond strength of and etch-and-rinse adhesive system.
**Results:** Mean bond strength in G1 was 35.03 ± 8.94MPa, in G2 was 38.73 ± 8.97. ANOVA test showed any influence of CHXLNs pretreatment on the bond strength of adhesive tested. CLMS showed that CHXLNs are present under adhesive resin tags.

**Conclusion:** Within the limits of this study we can conclude that CHXLNs do not influence bond strength of etch-and-rinse adhesive system. The effect of CHXLNs on bond strength durability is under investigation.

## BM18

### Influence of Synthetic Hydroxyapatite application on fiber posts bond strength and durability.

Diletta Basile¹, Emanuele Bergantin¹, Gianluca Turco², Milena Cadenaro², Lorenzo Breschi³, Elio Berutti¹, Nicola Scotti¹

¹Dental school, university of Turin, Torino, Italy, ²University of Trieste, Department of Medical Sciences, Trieste, Italy, ³Alma Mater Studiorum, University of Bologna, DIBINEM, Bologna, Italy

**Objective:** The aim of this in vitro study was to evaluate the effect of Calcium-Phosphate minerals application on fiber post bond strength and durability.

**Methods:** 64 single-root teeth were endodontically treated and a 10mm post space was prepared in each sample. Specimens were randomly assigned to four groups (n = 16) according to the fiber post luting procedures. G1: EDTA10% + self-adhesive cement (Panavia SA, Kuraray); G2: EDTA 10% + TeethMate Desensitiser (Kuraray) + self-adhesive cement (Panavia SA, Kuraray) G3: AllBond Universal (Bisco) + Core-X Flow (Dentsply); G4: AllBond Universal (Bisco) + TeethMate Desensitiser (Kuraray) + Core-X Flow (Dentsply). Teeth were cut in 1mm thick slices; sample were pushed until failure with an Instron Machine after 24h and 12 months of storage in artificial buffer at 37°C. 2 samples per group were prepared for the SEM analysis. An EDS (EDAX Integrated GENESIS APEX 2i EDS System with Apollo X Silicon Drift Detector) detector was used together with the SEM for elemental analysis of the sample’s surface. Results were statistically analyzed with one-way ANOVA test (p < 0.05).

**Results:** Statistical analysis showed a significant difference in bond strength between G1 and G2 (p = 0,0001) and between G3 and G4 (p = 0,001). Hydroxyapatite application significantly helps to prevent bond strength decrease overtime (p = 0.0001). EDAX analysis showed that TeethMate created a Calcium-Phosphate precipitation over dentinal tubules.

**Conclusion:** Within the limitations of an in vitro study we can affirm that the creation of calcium-phosphate precipitation over dentinal walls could improve and stabilize bond strength of fiber post luted with 10 MDP-containing adhesive systems.

## BM19

### Ultrashort pulsed lasers - Effects on dental tissues and restorative materials

Joerg Meister¹, Florian Schelle², Claudia Dehn¹, Matthias Frentzen¹

¹Dept. of Periodontology, Conservative and Preventive Dentistry, Bonn University, Dental Faculty, Bonn, Germany, ²Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA), Sankt Augustin, Germany

In recent years ultrashort pulsed lasers (USPL) were introduced into dental laser research. The aim of this technology is to ablate oral hard and soft tissues as well as restorative materials with minimal collateral damages at sufficient ablation rates under the condition of high precision and minimal pain.

Basic investigations with the present technology were carried out with Nd:YVO₄ laser systems emitting light in the spectral range of 1 µm at pulse durations of 8 ps and pulse repetition rates of 500 kHz. The average power is 9 W. With a M² of 1.1 and a beam diameter of 30 µm, the corresponding intensity of the laser is 300 GW/cm². Additionally, comparable high power ablation rate measurements were performed employing a laser source with an average power up to 50 W. Irradiations were carried out with a scanner system and without a water spray.

Threshold values in the range of 0.45 J/cm² (composite) to 1.54 J/cm² (enamel) were observed. An ablation rate of up to 37.53 mm³/min for composite material was achieved with the 9 W laser source. Be employing the 50 W laser, increased rates up to ~50 mm³/min i.e., for dentin were obtained.

The current state of this technology regarding dental material processing (oral and restorative materials) including advantages, limitations and future prospects of this technology will be presented.

## BM20

### Antimicrobial Activity of Octenidine Dihydrochloride, Polyhexanide and Chlorhexidine Digluconate Against Cariogenic Microorganisms

Esra Uzer Celok¹, Mustafa Ates², Ayse Tugce Tunac¹, Bilge Hakan Sen³

¹Department of Restorative Dentistry, Faculty of Dentistry, Izmir Katip Celebi University, Izmir, Turkey, ²Division of Basic and Industrial Microbiology, Department of Biology, Faculty of Science, Ege University, Izmir, Turkey, ³Private Practice, Izmir, Turkey

**Aim:** The aim of this study was to assess the antimicrobial in-vitro effects of octenidine dihydrochloride, polyhexanide and chlorhexidine digluconate on cariogenic microorganisms by using their minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC).

**Materials and Methods:** Streptococcus mutans (ATCC 25175), Lactobacillus acidophilus (ATCC 4356), Lactobacillus rhamnosus (ATCC 7469) and Actinomyces viscosus (ATCC 15987) were submitted to broth microdilution of octenidine dihydrochloride and polyhexanide at 1000-3 mg/L and chlorhexidine digluconate at 10.000-30 mg/L. After the tubes were incubated at 37°C for 48 h and they were read in a spectrophotometer in order to detect the MIC. A new subculture was placed on agar plates to obtain the MBC.

**Results:** Different MIC and MBC were observed in all disinfectants against each microorganism. The lowest MIC and MBC against S. mutans (60 mg/L) were obtained from polyhexanide while the lowest values against L. acidophilus (15 mg/L, 30 mg/L) L. rhamnosus (15mg/L, 30 mg/L) and A. viscosus (30 mg/L) were determined by octenidine dihydrochloride.

**Conclusion:** Octenidine dihydrochloride and polyhexanide have the potential to be replaced with chlorhexidine digluconate as they were effective on cariogenic microorganisms.
## BM21

### Microleakage of Class II cavities restored with bulk-fill restorative resins

Tugce Guney, A.Ruya Yazici

Hacettepe University, School of Dentistry, Department of Restorative Dentistry, Ankara, Turkey

**Objective:** The aim of this in vitro study was to evaluate the microleakage of Class II cavities restored with different restorative resins; bulk-fill resin composite, bulk-fill flowable resin, fiber-reinforced resin composite and a nanohybrid resin composite.

**Materials and Methods:** Forty-eight extracted non-caries human molars were used for the study. In each tooth standardized Class II (slot) cavities were prepared (on mesial and distal surfaces) with one having the gingival margin below, one above the cementoenamel junction (CEJ). After preparation the teeth were randomly assigned into four groups of twelve specimens each (n = 12). The cavities were restored with; Group 1: Tetric EvoCeram Bulk Fill (Ivoclar/Vivadent); Group 2: SureFil SDR Flow + Ceram X Mono (Dentsply); Group 3: GCeverX posterior + G-aenial posterior(GC Corp.); Group 4: Filtek Supreme(3M ESPE). Each restorative material was used with its respective adhesive system. The restored teeth were stored in distilled water for 24 h at 37 °C and then thermocycled (5-55°C, x1000) before immersion in 0.5% basic fuchsin dye for 24 h. The teeth were then rinsed and sectioned mesiodistally and dye penetration was scored under a stereomicroscope(20X). Data were statistically analyzed using the Kruskal-Wallis and Mann-Whitney U tests (p < 0.05).

**Results:** The Kruskal-Wallis test revealed no significant differences in microleakage scores among all groups either on enamel (p = 0.296) or on dentin (p = 0.788).

**Conclusion:** None of the restorative materials tested completely eliminated microleakage. Nanohybrid resin composite, fiber-reinforced resin composite and bulk-fill resins either flowable or not showed similar microleakage values.

## BM22

### Effect of exposure distance with MultiLED lamps on surface micro-hardness in a bulk-fill composite.

Oana Andreea Miclaus, Allegra Comba, Damiano Pasqualini, Mario Alovisi, Elio Berutti, Nicola Scotti

University of Turin, Department of Surgical Sciences, Dental School, Turin, Italy

**Objectives:** The aim of this in vitro study was to assess the effect of exposure distance on surface microhardness obtained with different MultiLED curing lights of a bulk-fill composites. The hypothesis is that polywave multiLED curing lights induce uniform microhardness distribution on composite surface independently of curing distance.

**Methods:** A bulk-fill composite (Filtek Bulk Fill Posterior, 3M ESPE) was selected and placed in a 2mm metallic mould.

Samples were exposed to irradiation with 3 different curing lights: TwoWave-Heraeus (Group1), Valo-Ultradent (Group 2), Swiss Master Light-EMS (Group 3) at the same energy density (27J/cm2). Polymerization was performed with the curing tip at a distance of 0mm, 2mm, 4mm, 6mm and 8mm from the top surface of the sample. All specimens were stored in distilled water in a light-proof container at 37°C for 24 hours. Top and bottom surface of samples were submitted to Vickers test on the central and peripheral area. Analysis of variance (ANOVA) was performed to evaluate the effects of light distance, sample zone (central vs peripheral), curing light and their interactions on microhardness. All statistical analyses were performed at a significance level of 0.05.

**Results:** Exposure distance significantly influenced microhardness with all tested lamps (p = 0.0001). Between curing units, TwoWave performed significantly better than Valo and Halogen light (p = 0.0001). Sample central area was significantly harder than peripheral area in all groups (p = 0.0001).

**Conclusions:** The initial hypothesis is rejected, since exposure distance, curing light and surface zone all significantly affected surface microhardness of bulk-fill resin composite.

## BM23

### Cytotoxicity of high temperature pressure polymerized resin infiltrated ceramic networks on human oral stem cells

Eric Bonte<sup>1,4</sup>, Mathilde Tassin<sup>2</sup>, Tsouria Berbar<sup>2</sup>, Ludwig Loison Robert<sup>1</sup>,<sup>2</sup>, Michael Sadoun<sup>1,3</sup>, Benjamin Fournier<sup>5,2</sup>

<sup>1</sup>Paris Descartes University, Sorbonne Paris Cité, Dental faculty, Paris, France, <sup>2</sup>INSERM UMR 1138, Cordeliers research center, Paris, France, <sup>3</sup>URB2i, Paris Descartes Dental faculty, Paris, France, <sup>4</sup>Bretonneau Hospital, AP-HP, Paris, France, <sup>5</sup>Paris Diderot University, dental faculty Garancière, Paris, France

**Background:** The development of CAD - CAM techniques revealed the need for new materials suited to this technique and offering a safe and sustainable clinical implementation. The infiltration of resin in a ceramic network under high pressure and high temperature defines a new class of hybrid materials for this purpose which requires to be evaluated by cytotoxicity. We used oral stem cells (gingival and pulpal) as an in vitro experiment model.

**Methods:** In this study, 4 biomaterials were powdered and assessed at 2mg/ml: Enamic (Vita), Experimental hybrid material (EHM), EHM with initiator (EHMi) and polymerized Z100 composite material (3M) on oral stem cells. Viability, apoptosis, proliferation, cytoskeleton, inflammatory response, oxidative stress and morphology (SEM) were evaluated. Statistical analysis (ANOVA) was performed using GraphPad Prism6 (Graphpad Software inc, 6.0) software.

**Results:** Proliferation was delayed by all the tested biomaterials but no difference was observed between them. Study of the cytotoxicity revealed less viable cells in presence of Z100 (MTS assay), however no significant apoptosis occurred. Cytoskeleton and extracellular matrix synthesis were not altered and an intimate contact appeared between materials and cells.

**Conclusion:** The four polymerized and powdered materials tested did not exhibit adverse effects on oral stem cells in our experimental conditions.
## BM24

**Which methodological factors influence the shear-bond strength of fissure sealants?**

Vinay Pitchika¹, Meng-Ling Chiang², Sebastian Birlbauer¹, Alexander Crispin¹, Reinhard Hickel¹, Nicoleta Ilie¹, Jan Kühnisch¹

¹Ludwig Maximilians University of Munich, Munich, Germany, ²School of Dentistry, Taipei, Taiwan

**Objective:** This study aimed to investigate the influence of different methodological variables on shear-bond strength (SBS), e.g. tooth surface, enamel pretreatment, specimen alteration and shearing technique.

**Methods:** 180 healthy, caries-free, extracted human third molars were selected. All roots were sectioned off 1mm apical to cement-enamel-junction and the crowns were divided into four surfaces (mesial/ distal/oral/ buccal). The resulting 720 tooth pieces were embedded, numbered and randomly allocated to the pre-treatment (prismatic/aprismatic enamel and 30/ 60sec etching time), alteration (1day/ 3months water storage/ 5000x thermocycling), and shearing method (Ultradent/ Guillotine). Finally, 18 groups each containing 40 specimens (10 of every surface) were formed. All sealants (Helioseal, Vivadent, Schaan, Liechtenstein) were placed using the cylindrical mould insert which was fixed in a bonding clamp (ISO 29022) according to the specification of each group. After specimen storage, the shearing force was measured in a universal testing machine (MCE 2000ST, Quicktest, Langenfeld, Germany). Unpaired t-tests, one-way ANOVA, linear regression and multiple linear regressions were used for data analysis.

**Results:** There were significances between the groups under t-test and one-way ANOVA test. All of the included factors were significant under linear regression, which were then included into multiple linear regression; resulting in a significant model with aprismatic enamel, distal surface and 5000x thermocycling as significant factors.

**Conclusion:** While specimen preparation and thermocycling showed an significant influence on SBS, the shearing method and chosen enamel surface might act as confounders and should be controlled in future in-vitro sealant trials.

## BM25

**Immediate adhesive properties to dentine of two “universal” adhesives**

Maria Cura, Ana Hurtado, Maria Victoria Fuentes, Laura Ceballos

Rey Juan Carlos University, Madrid, Spain

**Objective:** To determine microtensile bond strength (µTBS) to dentine and degree of conversion inside the hybrid layer (DC) of two “universal” adhesives using self-etch or etch-and-rinse strategies in comparison with a 2-step self-etch adhesive.

**Methods:** 50 extracted caries-free human molars were assigned to five groups: 1) the “universal” adhesive Xeno Select (Dentsply), applied as a one-step self-etch adhesive (XE-1SE); 2) Xeno Select, applied as a 2-step etch and rinse adhesive (XS-2ER); 3) the “universal” adhesive Scotchbond Universal adhesive (3M ESPE), applied as a one-step self-etch adhesive (SBU-1SE); 4) Scotchbond Universal adhesive applied as a 2-step etch-and-rinse adhesive (SBU-2ER); 5) A 2-step self-etch adhesive, Clearfil SE Bond (CSE, Kuraray). Specimens were prepared for µTBS test and for DC determination by micro-Raman spectroscopy. Data were analyzed by ANOVA and Tukey test (p < 0.05).

**Results:** µTBS mean values in MPa (standard deviation) were: XE-1SE 18,24 (12,8) b; XS-2ER 22,71 (12,0) b; SBU-1SE 55,94 (23,6) a; SBU-2ER 59,30 (16,4) a; CSE 58,77 (23,3) a; and DC in % (standard deviation) were: XE-1SE 53,34 (16,5) b; XS-2ER 70,19 (11,2) a; SBU-1SE 76,32 (13,7) a; SBU-2ER 77,25 (16,5) a; CSE 79,16 (10,8) a.

**Conclusions:** Clearfil SE and Scotchbond Universal, used as 2-step etch-and-rinse or as a one-step self-etch adhesive, yielded higher bond strength to dentin than Xeno Select. Xeno Select as a self-etch adhesive had a significantly lower DC than the other testing groups.

## BM26

**Bisphenol A release: a comprehensive survey on the composite resin composition.**

Elisabeth Dursun¹,³, Jean-Pierre Attal¹,⁴, Hélène Fron¹,⁴, Anne Raskin¹,⁵

¹Paris Descartes University, Paris, France, ²Aix-Marseille University, Marseille, France, ³A. Chevenevier Hospital, Creteil, France, ⁴C. Foix Hospital, Ivry-sur-Seine, France, ⁵La Timone Hospital, Marseille, France

**Introduction:** Bisphenol A (BPA) is an endocrine disruptor with a potential toxicity. If the composite resins (CR) do not contain pure BPA, its derivatives are widely used. Several studies reported BPA levels and its derivatives in the saliva or urine after the placement of CR. The aims of our study were: to establish an exhaustive list of the CR and their composition; to assess to what extent BPA derivatives are used.

**Method:** A search on the manufacturers' websites was performed to reference all the CR marketed in Europe. A comprehensive search of their composition was then carried out from both material safety data sheets and standardized questionnaire sent to manufacturers. They should: indicate if their CR contained the monomers listed; add other monomers; note « no communicated », if they did not want to give any details. The results were recorded and analyzed using the Excel software.

**Results:** 160 CR have been identified in 31 manufacturers. 24 manufacturers (77,4%) responded to our survey. When they have not responded (22,6%), the web research was not sufficient to complete the CR composition. 61% are based on bis-GMA, or bis-GMA and UDMA; 15% on UDMA; 5% do not contain bis-GMA, nor UDMA; for 19%, it was not communicated. One CR contains bis-DMA.

**Conclusion:** Even the scientific evidence encouraging to stop using CR with BPA derivatives, it may seem logical to select CR without them, for the population at risk (children and pregnant women). This work has established a list of 19 possible products.

## BM27

**Vickers Micro-Hardness evaluation of two fiber-post dual cements cured with three different time protocols**

Maria Luisa Favale, Elena Manzon, Dorina Selaj, Allegra Comba, Elio Berutti, Nicola Scotti
University of Turin, Department of Surgical Sciences, Dental School, Torino, Italy

**Objectives:** The aim of this in vitro study was to assess the effect of three different curing protocols on the micro-hardness (MH) of one self-adhesive and one dual-curing cement. The null hypothesis tested is that different waiting times before light curing do not influence MH of dual-curing cements.

**Methods:** To conduct the in vitro study, 48 cement samples were prepared using a custom-made metallic mold that simulates post-space in terms of depth, diameter and light conditions. Samples were divided into 2 groups (n = 24) according to the dual-curing cement employed: 1) Self-adhesive resin cement (Rely-X Unicem 2, 3M ESPE); 2) Dual-curing cement (Clearfil DC Core, Kuraray). Each group was further divided into three subgroups considering the curing protocol: a) 60 sec. curing after one minute of waiting time; b) 60 sec. curing after five minutes of waiting time; c) 60 sec. curing after nine minutes of waiting time. Vikers MH for each sample, for both the coronal and the apical area, was obtained using a nano-indentometer. One-way Anova was performed to evaluate the effects of different waiting times before polymerization on MH of the coronal and apical portion.

**Results:** Anova test showed that for the three subgroups of both cement there was a significantly higher MH in the coronal portion (p = 0.0001). Further, significant MH differences (p = 0.0001) concerning curing protocol were found only for DC Core.

**Conclusions:** The null hypothesis is partially not rejected because longer waiting time before curing only improve MH values of DC Core and not of Rely-X Unicem2.

## BM28

### Effect of etch-and-dry and etch-and-rinse application of universal adhesives on post-operative sensitivity: randomized clinical trial

Gabriele Petrini, Marco Zante, Oana Miclaus, Nicola Scotti, Damiano Pasqualini, Mario Alovisi, Elio Berutti
Dental School, University of Turin, Turin, Italy

**Purpose:** In this in vivo study we evaluated the influence of application technique of three universal on immediate post-operative sensitivity (POS).

**Methods:** In total, 100 patients with one posterior tooth affected by a primary carious lesion were recruited. The patients were randomly divided into three groups, based on the universal adhesive systems employed: group A (All Bond Universal, Bisco); group B (Scotchbond Universal, 3M ESPE); group C (Futurabond U, VoCo). Every adhesive was randomly applied with etch-and-rinse (application of 36% phosphoric acid for 15 sec) or etch-and-dry technique. The same skilled operator carried out the restorations using a nano-hybrid composite (GrandioSo, Voco) in oblique stratification. Each increment was light-cured for 20 s with a LED lamp. Patients received a three-level thermal sensitivity form for post-operative sensitivity ratings. The evaluations were recorded daily for 7 days. POS trends were analyzed with the Friedman test (p < 0.05).

**Results:** All (100%) enrolled patients completed the follow-up visits. There was no statistically significant difference between the three groups

in post-operative sensitivity trends. In every groups, increased post-operative sensitivity was found at T1, which then decreased significantly during the observation period. Adhesive application technique did not significantly influence POS.

**Conclusion:** The results of this clinical trial showed that universal adhesives, applied either with etch-and-rinse or etch-and-dry technique, avoided POS after direct posterior composite restorations. Follow-up visits of treated patients are scheduled to analyze clinical longevity of restorations performed in this clinical trial.

## BM29

### Mercury in Dental Amalgam. What do North Iraqi Patients think?

Abdülkadir Sengun¹, Hakan Colak², Errtugrul Ercan¹, Mehmet Mustafa Hamidi¹, Hassan Al Yousuf⁰

¹Kirikkale University School of Dentistry Department of Restorative Dentistry, Kirikkale, Turkey, ²Ishik University School of Dentistry Department of Restorative Dentistry, Erbil, Iraq

**Aim:** The aim of this study is to assess the awareness about the toxicity of mercury in dental amalgam among sample of dental patients in North of Iraq.

**Material methods:** A cross-sectional survey was conducted among 518 dental outpatients who attended Ishik University School of Dentistry Clinics. Data were collected using structured questionnaires. They were asked ingredients of the amalgam, opinion about mercury pollution in the environment, health problems associated with mercury.

**Results:** Thirty four percent of respondents claimed that silver fillings contain mercury. The majority of respondents stated that they will prefer higher cost fillings contain no mercury rather than lower cost fillings that contains mercury. There is overwhelming opinion (96,3%) that dentists should be required to inform their patients about the various types of mercury and non-mercury fillings available before filling a cavity. Approximately 21,8% reported mercury may cause health problems in Human Beings while 73, 5% claimed they don't have any idea. Only 3.6% of participants claimed to receive dental amalgam despite prior knowledge of its mercury content.

**Conclusion:** This study demonstrated that general knowledge and awareness of toxicity of mercury in dental amalgam is relatively low among North Iraqi dental patients

## BM30

### Effect of polywave multiLED curing lights on surface micro-hardness distribution of two nanofilled composites.

Marco Zante, Allegra Comba, Damiano Pasqualini, Mario Alovisi, Elio Berutti, Nicola Scotti
University of Turin, Department of Surgical Sciences, Dental School, Turin, Italy

**Objectives:** The aim of this in vitro study was to assess the effect of different poliwave MultiLED curing lights on surface microhardness
topography of two nanofilled composites. The hypothesis is that polywave multiLED curing lights induce uniform microhardness distribution on composite surface.

**Methods:** A non-carious molar tooth, extracted for periodontal reasons, was selected. Crown was horizontally sectioned 2-mm above the CEJ. A 3x4-mm Class I cavity was prepared in order to obtain a "tooth mould". Composite samples, 2mm thick, were prepared using the tooth mould and divided in two groups (n = 10 each) according to the composite (GrandioSo - VoCo, Germany; Filtek XTE - 3M ESPE, USA). Samples were cured with 5 curing lights (TwoWave-Heraeus, Valo-Ultradent, Bluephase G2-Ivoclar Vivadent, Demi Ultra-Kerr, Swiss Master Light-EMS) at the same energy density (27J/cm²). After 7 days of storage, composite samples were submitted to Vickers test on the central and peripheral area. Analysis of variance (ANOVA) was performed to evaluate the effects of curing light and specimen zone (central vs peripheral) and their interactions on microhardness.

**Results:** Two-way Anova showed comparable results for both composites (Filtek and GrandioSo). The two variables (lamp and zone) statistically affected micro-hardness (p < 0.0001), but not the interactions between them.

**Conclusions:** The two composites employed showed a decrease in micro-hardness values from the central to the peripheral area for all five curing lamps, thus the initial null hypothesis must be rejected. Probably the hardness distribution of composite surface reflects the irradiance distribution of each curing light tested in this study.

## BM31

### Effect of the interface geometry on the stress distribution of the restored tooth-ceramic crown complex

Raad Al Marza, Shirin Shahrbaf, Nicolas Martin

The University of Sheffield, Sheffield, UK

**Objective:** The effect of the cement interface geometry on the structural integrity of the tooth ceramic-crown complex is poorly understood. This work investigates, by means of three-dimensional finite element analysis (3D FEA) the effect of the interface geometry (thickness and uniformity) on the stress state of the tooth ceramic-crown complex.

**Method:** Two typodont maxillary first premolar teeth were restored with lithium disilicate all-ceramic crowns fabricated to create two different interface geometries: (i) Wide and non-uniform (mean 157µm ±36) and; (ii) thin and uniform (mean 114µm ±19). These were adhesively cemented using Variolink II resin cement (Ivoclar-Vivadent AG, Liechtenstein) and subsequently digitized with a micro-CT scanner. An image processing software program (Mimics, Materialise Ltd) and haptic technology (Freeform, SensAble Technologies Inc) were used to generate a 3D model and supporting structures (PDL, alveolar/cortical bone). Theose high-resolution 3D digital models of the restored tooth and supporting structures were converted into 3D-FEA models using the Hypermesh software package v.10.0 (Altair Engineering Inc). The boundary condition was defined at the outermost surface of the supporting bone. Each of the structures was assumed to be homogenous, with an isotropic structure and have linear elastic behaviour. A static occlusal load of 300N was applied and the resultant generated stresses were calculated (von Mises and Principal).

**Result:** The stress values were less in the ceramic crown and cement structures of the thinner and more uniform interface space model.

**Conclusion:** The stress distribution in the tooth components varied greatly between models and was affected by the cement interface thickness and uniformity.

## BM32

### Degree of conversion and micro-hardness of a light-curing cement under lithium-disilicate and composite discs

Atdhe Grezda, Allegra Comba, Damiano Pasqualini, Mario Alovisi, Elio

Berutti, Nicola Scotti

University of Turin, Turin, Italy

**Objective:** evaluate the conversion degree (DC) and the micro-hardness (MH) of light curing cement under lithium disilicate and composite discs of different thicknesses. The null hypothesis were that (1) thickness and (2) material do not influenced resin cement DC and MH.

**Methods:** 15 lithium-disilicate discs (E-Max CAD) 2cm of diameter, A2 shade LT and 15 composite discs (LavaUltimate 3M), A2 shade LT, were prepared and divided into three groups (n = 5) according to the thickness: A) 0.6 mm; B) 1mm; C) 1.5mm. Adhesive procedures were performed on a single surface of each disc following manufacturer instruction and Choice2 light-curing cement (Bisco) was applied. Curing was performed with a multiLED polywave lamp (Valo) for 60sec at 1700mW/cm2 with the lamp in slight contact with the opposite surface towards the cement layer. DC% of the cement was evaluated with ATR FT-IR spectrophotometer (Thermo Scientific Nicolet IS10) both for the ceramic and the composite discs. Once the DC was established, a Vickers Test was performed on the cement with a micro-indentometer. Three indentations were performed on each sample and the mean value was considered for statistical analysis. ANOVA test was performed to evaluate the influence of thickness and material on DC% and MH.

**Results:** ANOVA showed that DC% were not dependent on material and thickness while MH values were affected by both thickness and material (p < 0.05).

**Conclusion:** Null hypothesis (1) and (2) were not rejected since only MH values were influenced by thickness and material when a light curing cement is used for cementation.

## BM33

### Quality of Final Impressions and Prescriptions for Fixed Restorations.

Neamat Abubakr¹,², Riham Nabil¹

¹University of Khartoum, Faculty of Dentistry, Khartoum, Sudan, ²Princess Nourah Bint Abdelrahman University, College of Dentistry, Ri-yadh, Saudi Arabia

**Purpose:** The purpose of this study was to investigate the quality of final impressions and prescriptions for fixed restorations that were received by private and educational institute's laboratories.
**Methods:** Two hundred and seventeen questionnaires were distrib-
uted to eight private laboratories and seven dental schools. The
questionnaires were filled by the dental technicians; who were
trained and instructed to complete one questionnaire per one final
impression for fixed restoration immediately after it was received.

**Results:** Total response rate was 87%; the responding technicians had found evidence of obvious contamination in 23.8% of the examined impressions; blood was clear in 68.9% of these cases. Metal stock trays were used in 57.1% of the examined sample. About two-third of the impressions had been taken using condensation silicone (64.6%). Poor or no written instructions were observed in half of the sample (n = 103).

**Conclusions:** Within the limitation of the present study, results showed an inappropriate selection of material for final impression; the cross-infection control of the sent impressions was below standard and there were poor prescriptions and communications with laboratory technicians. Clinical Implications: Proper infection control need to be applied for both dentists and dental technician. Appropriate impression material and proper communication with dental laboratory technicians will definitely improve the quality of fixed prosthodontics work.

BM34

Surface roughness of nano-hybrid composites before and after im-
mersing in sports drink

Elif Ozturk¹, Gizem Guder²

¹Hacettepe University, Ankara, Turkey, ²Kocaeli University, Kocaeli, Turkey

**Objectives:** The purpose of this study was to evaluate the differences in surface roughnesses of two different nano-hybrid composite after immersing in a sports drink.

**Methods:** Fourty disk-shaped specimens (diameter:10-mm;thickness:2-mm) were prepared from two different nano-hybrid resin composites (Cavex Quadrant Universal LC, Cavex, Haarlem, The Netherlands and Tetric N-Ceram, Ivoclar Vivadent, Schaan, Liechtenstein). Each specimen was cured under the mylar strips for 20 seconds from each of top and bottom surfaces. All the specimens were stored in distilled water for 24 h at 37°C. Baseline measurements of surface roughness (Ra) values were performed with a 3D-optical-profilometer (NewView™ 7200, Zygo). Specimens were immersed in a sports drink (Redbull, The Coca-Cola Co., Turkey) 3 minutes daily for a period of 30 days. Control groups were stored in distilled water only. Surface roughnesses were measured after the immersion period. For each composite 3 measurements were performed and the average was recorded. Data were statistically analyzed using Univariate Analysis of Variance test (SPSS 20.0) (p = 0.05).

**Results:** There was statistically no difference between the Ra values of the study groups before or after immersing in distilled water or sports drink (p > 0.05).

**Conclusions:** The tested sports drink did not cause any alteration in 3D-surface roughnesses of the selected nano-hybrid composites for a 30-day evaluation period.

BM35

Effect of water storage and brushing on dentinal permeability of
teeth treated with desensitizing agents

Luca Debernardi¹, Emanuele Bergantin¹, Gianluca Turco², Elio Berutti¹,
Nicola Scotti¹

¹University of Turin, Department of Surgical Sciences, Dental School, Torino, Italy, ²University of Trieste, Department of Medical Sciences, Trieste, Italy

**Objectives:** The aim of this in vitro study was to assess the effect of ageing and electric brushing on dentinal permeability of samples previously treated with three different desensitizing agents. The null hypothesis is that dentinal permeability is not influenced by ageing and periodical electric brushing.

**Methods:** 18 intact molars were selected, occlusal enamel and crowns were then cut in 0,5 mm slices, perpendicular to the long axis of the teeth, in order to obtain 1mm thick dentin discs. Samples were than randomly divided into 3 groups according to desensitizing treatment performed: 1) ReminPro (Voco); 2) AllBond Universal (Bisco); 3) TeethMate Desensitizer (Kuraray). Groups were further divided into 2 subgroups considering different ageing treatment: a) storage in artificial saliva; b) subgroup a) treatment + 10 min standardized brushing once a week for 3 months. Dentin permeability was assessed before and immediately after treatment, after 3 months of ageing treatment. Samples were subsequently prepared for SEM analysis to evaluate differences in tubules occlusion. Kruskal-Wallis and Wilcoxon test were performed to evaluate dentin permeability changes before and after samples treatment (p < 0.05).

**Results:** Statistical analysis showed that water storage (p < 0.001) and brushing (p < 0.0001) significantly increased dentin permeability except for TeethMate Desensitizer.

**Conclusions:** All occluding agents reveal comparable tubular occlusion at baseline SEM analysis. However, statistical analysis showed that water storage and daily brushing increase dentin permeability for all groups except for TeethMate Desensitizer that remain stable both after storage in artificial saliva and controlled brushing.

BM36

Effect of immediate or delayed dentinal sealing on coronal bond
strength: µTBS test

Francesco Lerda

University of Turin, Turin, Italy

**Objective:** The aim of this in-vitro study was to evaluate the influence of immediate or delayed adhesive system application on coronal dentin bond-strength. The null hypothesis is that immediate dentinal sealing (IDS) do not provide higher bond strength than delayed dentinal sealing (DDS), independently of the adhesive technique.

**Methods:** 30 molars crowns were flattened and standardized smear layer was created with 600grit paper. Samples were randomly divided in 6 groups according to adhesive treatment:

G1 IDS with 3step etch-and-rinse (Optibond FL, Kerr)

G2 IDS with EDTA10% for 1min, TeethMate Desensitizer (Kuraray), water rinse for 10sec, 2step self-etch adhesive application (Clearfil SE Bond 2, Kuraray).

G3 IDS with 2step self-etch adhesive application (Clearfil SE Bond 2).

G4 DDS (after 8weeks of storage in artificial saliva at 37°C) with G1 procedure
G5 DDS with G2 procedure

G6 DDS with G3 procedure

Then 4mm resin composite was applied and cured with LED lamp. Specimens were serially sectioned to obtain 1-mm-thick beams in accordance with the µTBS test technique. Beams were stressed to failure after 24h. Two-way Anova was performed to evaluate the effects of immediate/delayed sealing and adhesive procedure on coronal bond strength.

**Results:** Two-way Anova showed that adhesive technique did not influenced immediate bond strength, while delayed bond strength was significantly worst (p = 0.0001).

**Conclusion:** Null hypothesis are partially refused since the immediate dentinal sealing provide higher bond strength, independently of the adhesive technique.

## BM37

### Effect of Er-YAG or bur on bond strength with different adhesive procedures

aristea cedrone, allegra comba, riccardo tempesta, elio berutti, nicola scotti
*University of Turin, Turin, Italy*

**Purpose:** Er-YAG laser treatment could influence adhesive effectiveness. The aim of this in vitro study is to evaluate the bond strength obtained with different adhesive strategies on coronal dentin cutted with Er-YAG laser or bur

**Methods and Materials:** 40 molars crowns were flattened and standardized smear layer was created. Samples were divided in 2 groups according to the dentin cutting technique (n = 20): Er-YAG laser or bur. Every group was then dividend in subgroups (n = 5 each) according to the adhesive technique:

SG1 dentin etching for 15 sec and universal adhesive application (AllBond Universal, Bisco)

SG2 universal adhesive application (AllBond Universal)

SG3 2step self-etch adhesive application (Clearfil SEBond 2, Kuraray)

SG4 3step etch-and-rinse adhesive application (Optibond FL, Kerr)

Adhesives were all cured for 60sec at 1400mW with Valo. Then resin composite was applied. Specimens were serially sectioned to obtain 1-mm-thick beams in accordance with the µTBS test technique. Beams were stressed to failure after 7 days of storage in artificial buffer. Two-way ANOVA was performed to evaluate the effects of cutting technique (CT) and adhesive technique (AT) and their interaction on the coronal dentin bond strength. Significance was set at p < 0.05.

**Results:** AT showed significant influence on coronal dentin bond strength (p = 0.0001), while CT did not.

**Conclusion:** Within the limits of this study we can conclude that Er-YAG treatment on coronal dentin did not affect the bond strength, above all with etch-and-dry techniques. Further investigations on bond strength stability are necessary.

## BM38

### Pulp chamber temperature increase during adhesive system irradiation with multiLED curing lights.

Giulia Massano, Francesca Barra, Francesco Coero Borga, Damiano Pasqualini, Elio Berutti, Nicola Scotti
*University of Turin, Turin, Italy*

**Objective:** The aim of this in vitro study was to compare temperature rise in the pulp chamber induced by different lights when curing adhesive system. The null hypothesis is that curing lights (1) and irradiation time (2) do not influence temperature increase.

**Methods:** 60 intact molars were selected. A first class cavity 3mm depth with pulpal floor 1mm distant from the pulp chamber was prepared on each sample. Roots were cut, a J-Type thermocouple was inserted into the pulp chamber that was then sealed. Samples were divided in 4 groups (n = 15) according to the curing light employed: Swiss Master Light (EMS), TwoWave (Heraeus), Valo (Ultradent), Bluephase Style (Ivoclar). Adhesive system (Clearfill Universal, Kuraray) was applied and irradiated with different time regimens (10sec, 20sec, and 40sec). Temperature rise in the pulp chamber, time to reach maximal temperature (tMax) and to return to initial temperature (tBack) were registered. Results were statistically analyzed with ANOVA test (p < 0.05).

**Results:** There were no statistically significant differences between halogen and multiLED tested curing lights regarding pulp chamber temperature increases when polymerizing a universal adhesive, independently of the irradiation time. The greatest temperature increases were observed with Valo (2.1 degrees Celsius), followed by halogen (1.4 degrees Celsius) and TwoWave and Bluephase Style (0.9 degrees Celsius). tBack was significantly higher (p = 0.0001) with halogen light.

**Conclusion:** Null hypothesis was accepted since curing lights tested did not differ in temperature increase induction, independently of irradiation time. However, halogen light induce more persistent heat in the pulp chamber.

## BM39

### Multimodal Optical Characterization of dentine caries lesions: multiphoton imaging, spectroscopy and micro-hardness analysis

Shara Sajini, Tlim Watson, Frederic Festy
*King's College London, London, UK*

Carious dentine is described clinically and histologically as two altered zones, a superficial infected and a deeper affected layer. Based on important structural features, the delineation between these layers is essential, both clinically and in laboratory investigations. The aim of this study was to evaluate and correlate objectively the autofluorescence (AF) features of sound, infected and affected carious dentine with their microhardness characteristics using a multimodal approach.

A total of 20 extracted carious molars were used in the study, a reference mark was created in each half. Using both halves: fluorescence and fluorescence life-time imaging (FLIM) in a two-photon microscope, localized areas were imaged, recorded, and the fluorescence spectrum was detected from each point as well as the second harmonic generation image (SHG). Afterwards, a single photon spectrometer was used to detect AF signal from the same areas. Finally, the Knoop microhardness (KHN) of these
areas was recorded and allocated subjectively into the three dentine zones. Significant statistical differences were found between the three zones delin- eating infected, affected and sound areas using these optical techniques. In conclusion, multiphoton imaging and single photon spectroscopy are con- sidered alternative non-invasive in-vitro diagnostic methods for caries char- acterisation through the detection of SHG signal, AF signal, and fluores- cence lifetime without dye labelling. These techniques have the potential to improve in-vitro cavity preparation through the better discrimination of the caries excavation endpoint, so avoiding excessive removal of tooth struc- ture. Consequently, they may also facilitate reliable evaluation of caries affected dentine remineralisation with bioactive materials.

## BM40

### Are the biomimetic therapies promising for direct pulp capping?

Elif Aybala Oktay¹, Ülkü Özan², Fulya Toksoy Topcu¹, Huseyin Tort¹
¹Gulhane Military Medical Academy, Department of Restorative Dentist- ry and Endodontics, Etlik/Ankara, Turkey, ²Abant Izzet Baysal University, Bolu, Turkey

**Objective:** To examine the cytotoxic effects of Emdogain(EMD) a puri- fied acidic biomaterial containing amelogenins which are obtained from pig in the embryological term and which are enamel matrix derivatives out of dentin bonding agents as pulp capping in the dental pulp therapies with RTCA-XCELLigence impedance method.

**Materials-Methods:** The cytotoxic effects of four different dentin agents (Tokuyama Bond Force, Shofu Beauti Bond, Dentsply Prime&Bond NT, 3M Adper Single Bond) used as pulp capping material in the direct pulp therapies and Emdogain(EMD), a enamel matrix deriv- ative, and a purified acidic biomaterial containing amelogenins obtained from pig in the embryological term on the dental pulp cells, with *RTCA XCELLigence* impedance method were analyzed.

Dental Pulp cell cultures were used between the third to sixth passage only in this study. Dental Pulp cell cultures were trans- ferred to the wells of x celligence to be used in the subsequent phases of this study. It was evaluated with real time cellular impedance method whether or not different doses of DBA’s added in media caused effects upon dental pulp in vitro. 1/250, 1/500 and 1/1000 dilutions of all medications were used.

**Result:** We found out that all doses of EMD decreased the cell growth based upon the days exposed and it showed no cytotoxic effect. Our results showed that some dentin bonding agents have cytotoxic effects on dental pulp cells and they may inhibit dental pulp regeneration by decreasing cell proliferation.

**Conclusion:** It can be concluded that Emdogain is a material which can be preferred for pulp capping against dentin bonding agents.

## BM41

### Characterization of resin ceramic as compared to polymer-infiltrated ceramic-network material and dense ceramics

Hazem Abouelleil¹, Alexis Goujat², Dominique Seux¹,², Julia Bosco³, Pierre Colon¹,³, Brigitte Grosgogeat¹,², Nelly Pradelle¹,³
¹Laboratoire des Multimatériaux et Interfaces ; UMR CNRS 5615, Université Lyon1, Lyon, France, ²UFR Odontologie, Université Lyon1 ; Service de Consultations et de Traitements Dentaires ; Hospices Civils de

Lyon, Lyon, France, ³UFR D'odontologie, Université Paris Diderot; APHP, Hôpital Rothschild, Service d'Odontologie, Paris, France

**Objectives:** Determine the fracture toughness, flexural strength and mod- ulus, and Vickers Hardness of a Resin Ceramic CAD/CAM material, GC CERASMART™, compared with commercially available materials: Lava™ Ultimate, 3M (Resin Ceramic), VITA ENAMIC®, VITA Zahnfabrik (polymer-infiltrated ceramic-network - PICN), VITABLOCS Mark II, VITA Zahnfabrik (feldspar ceramic) and e.max CAD, Ivoclar Vivadent (lithium disilicate glass-ceramic).

**Methods:** mini-bar specimens (3.0 x 3.0x14mm) were prepared for each CAD-CAM material. The flexural strength and elastic modulus were mea- sured using three-point-bending (ISO 6872:2008). Vickers microhardness measures (three measurements for each sample) were made with a micro- hardness tester (Struers, USA). The fracture toughness (KIC) of the mate- rials tested was determined using the Single Edge V-Notch Beam (SEVNB) method in accordance with standard ISO 6872. Fracture surfaces were analyzed using stereomicroscope and scanning electron microscopy (SEM). Results were analyzed via ANOVA with Turkey's t-test (p > 0.05).

**Results:** Significant differences were observed between the different CAD-CAD blocks. lithium-silicate glass ceramic performed better followed by the hybrid ceramic material and feldspar ceramic.

**Conclusion:** Results demonstrated that all the materials properties were within the acceptable range for fabrication of single restorations accord- ing to the ISO standard for ceramics (ISO 6872:2008). However, impor- tant differences between the materials tested are noticed as a function of their structure.

## BM42

### Compression Fracture Resistance of four different Glass-ionomer cements

Domagoj Glavina, Kristina Gorseta, Tomislav Skrinjaric
School of Dental Medicine University of Zagreb, Zagreb, Croatia

**Background:** Aim of the study was to compare fracture resistance to compression of four different GIC materials filled in Class II type cavities.

**Materials and Methods:** For the study purposes, zirconia ceramic class II cavity models were prepared according to standard prep- aration. Each test group comprised 6 samples (models). In order to prepare restorations models were filled with four different ma- terials: Equia Forte (GC), Equia (GC), Ketac molar (3MESPE) and Ionostar Molar (Voco). Materials were applied according to manufacturers' instructions and with aid of sectional (anatomical) matrix. Models were stored at 37°C (100% humidity) for 24h prior testing. Each specimen was tested using an Universal testing machine (LRX, Lloyd Instruments) at 1 mm/min crosshead speed and loaded to fracture using compression rod (diameter 1,5mm), with 1kN load cell. Statistical analysis of data was performed by one-way analysis of variance (ANOVA) and Tukey HSD post hoc test.

**Results:** Equia Forte showed significantly better fracture resistance com- paring to all other materials (Equia Forte 257,2N; Equia 222,1N; Ketac Molar 140,7N; Ionostar Molar 114,5N). Type of the fracture was cohesive
in all cases. Most Equia cavity models (samples filled with Equia Forte and Equia) fractured together with the restorations (73%).

**Conclusion:** Fracture resistance to compression of materials filled in Class II type ceramic cavities could be valuable testing procedure for GIC testing.

# Clinical Cases (CC)

## CC01

**Full-mouth rehabilitation in a patient affected by severe attrition: interdisciplinary peri-o-conservative and esthetic approach**

Vicente Faus-Matoses¹, Ignacio Faus-Matoses²,¹, Ana Teruel-Rodríguez¹, Vicente Faus-Llacer¹

¹University of Valencia. Master in Restorative Dentistry and Endodontics, Valencia/Valencia, Spain, ²University of Valencia. Master in Orthodontics, Valencia/Valencia, Spain

**Objective:** To illustrate a conservative approach combining surgical and restorative procedures to achieve the functional and aesthetic full-mouth rehabilitation of a patient with severe dental attrition, reduced vertical dimension and gummy smile.

**Methods:** Healthy 61 year-old female came to our dental clinic suffering from severe incisal wear and unsatisfied with her dental appearance. After clinical and radiographic examination a DSD was performed, from which we obtained a diagnostic wax-up. The wax-up was transferred to the mouth in order to carry out the clinical valuation of aesthetic parameters (anterior teeth’s length: assessing the position of gingival zeniths and incisal edges) through photographs and videos and afterwards the treatment plan was performed which included:

- Gingivectomy in the region of upper incisives.

- Direct oclusal composites to increase the vertical dimension on the non-restored posterior mandibular teeth.

- Improvement of anterior teeth’s aesthetics with minimally invasive feldspathic veneers.

- Replacement of all old obturations and prosthesis with resin, alumina and feldspathic restorations.

- Replace the absent posterior teeth with implants.

**Results:** It was possible to obtain a successful functional and aesthetic full-mouth rehabilitation with conservative and minimally invasive techniques.

**Conclusion:** With an accurate diagnosis, treatment plan and the use of the suitable materials it is possible to achieve excellent aesthetics and functional level while preserving maximum tooth structure.

## CC02

**Zirconia restoration with CAD-CAM system after orthodontic forced eruption with fiber-reinforced-composite**

Jun-Sung Park, Won-Gyun Chung, Yoon Lee

Yonsei University Wonju Severance Christian Hospital, Wonju, Gangwon-do, Republic of Korea

**Introduction:** If conventional restoration treatment of a tooth with advanced dental caries is not possible, orthodontic forced eruption can be one of the treatment options. For forced eruption in anterior teeth or premolars, the esthetic aspect as well as the functional aspect of the appliance has to be considered. In the past, metal wires and brackets caused unaesthetic appearance during forced eruption, and porcelain-fused-to-metal crowns resulted in dark gingiva appearance underneath the margin. In this case, the tooth was restored with a zirconia crown using CAD-CAM system after orthodontic forced eruption with fiber-reinforced-composite (FRC) and root canal treatment (RCT) of a premolar.

**Case report:** An 18 year-old male patient presented with advanced dental caries. After caries removal on the upper right second premolar, due to the deep subgingival margin, crown restoration after non-surgical RCT and orthodontic extrusion was planned. After discussing the esthetics with the patient, forced eruption using FRC and crown restoration with zirconia was recommended for the patient. After RCT, forced eruption of the tooth, and fiber post and core placement, the tooth was prepared for zirconia crown. Intraoral digital scan of the tooth was taken, and the tooth was restored with a zirconia crown fabricated by CAD-CAM system.

**Conclusions:** By using FRC, the esthetic as well as the functional needs of the patients can be fulfilled during the 2 ~ 3 month treatment period. The crown restoration procedure may be more comfortable and esthetic by using intraoral digital scan, CAD-CAM system and zirconia crown.

## CC03

**Interdisciplinary orthodontics-conservative treatment in a patient with overbite and attrition lesions**

Vicente Faus-Matoses¹, Ignacio Faus-Matoses²,¹, Lorenzo Valero-Remohi¹, Vicente Faus-Llacer¹

¹University of Valencia. Master in Restorative Dentistry and Endodontics, Valencia, Spain, ²University of Valencia. Master in Restorative Dentistry and Endodontics, Valencia, Spain

**Objective:** to describe a conservative approach using minimally invasive techniques in order to restore aesthetic and solve hipersensitivity in a patient with overbite and dental attrition.

**Methods:** A 37 years old was referred to our department. Her chief complaint was the dissatisfaction with her smile and hypersensitivity. After a photo study and the clinical examination, an interdisciplinary treatment plan including orthodontics, surgical and conservative procedures was performed:

- Direct oclusal composites in posterior mandibular teeth were placed to increase vertical dimension and achieving enough anterior space for the veneers.

- Orthodontics, including bite turbos on anterior teeth to correct overbite by extrusion of posterior teeth.

- Once the orthodontic treatment ended, occlusion was corrected and anterior space was achieved, a diagnostic wax up of the upper and lower veneers was done, it was transferred to the patient’s mouth for clinical evaluation in terms of shape, size, and length.

- Gingivectomy in the region of upper and lower anterior teeth was carried out.

- Replacement of the old upper veneers and placement of prepless lower veneers, all the new restorations were made with feldspathic ceramics.
**Results:** With this conservative approach we were able to obtain excellent aesthetic results solving hypersensitivity and functional issues with minimally invasive techniques.

**Conclusion:** With a conservative interdisciplinary treatment it is possible to obtain excellent aesthetic and functional results avoiding a great loss of tooth structure.

## CC04

### Interdisciplinary orthodontic conservative treatment in a patient affected by severe tetracycline stains, agenesias and malocclusion

Vicente Faus-Matoses¹, Ignacio Faus-Matoses²,¹, Elianys-Yoseli Mayares-Rodriguez¹, Vicente Faus-Llacer¹

¹University of Valencia. Master in Restorative Dentistry and Endodontics, Valencia/Valencia, Spain, ²University of Valencia. Master in Orthodontics, Valencia/Valencia, Spain

Case study of a 42 year old male patient that came into the clinic requiring a very conservative aesthetic and functional improvement of his mouth, due to the extensive grinding in both dental arches caused by dental malocclusion and severe tetracycline stains.

Initially the treatment plan led to put direct occlusal composites in the posterior affected teeth for the pathological grinding in order to raise vertical dimension and guarantee steady anterior restorations.

Following the plan, the proper use of orthodontics stabilized the occlusion and also placed well dental units 13 and 23 in the position of upper lateral incisors due to the existing agenesia.

A DSD generated a suitable reference guide for the final restorative treatment, compound by first of all, a wax up and a mock up that was placed over the patients teeth to visualize the final result and to have a better guide for the conservative engraving procedure.

An addition silicone impression was made after engraving procedure and sent to laboratory confection of veneers.

In order to opaque tetracycline stains, an opaque mycrohibrid composite (Esthet-X Dentsply. Konstanz, Germany) was placed at the buccal surface of each teeth and on top of this; the final restoration was cemented (Calibra – Dentsply. Konstanz, Germany)

Correct diagnosis and the proposed treatment plan was effective to fulfill the restorative demands of both the dentist and patient in terms of a conservative restorative approach to the problem.

## CC05

### Interdisciplinary approach: orthodontics and minimal-prep feldspathic veneers to rebuild the anterior guidance

Vicente Faus-Matoses, Ignacio Faus-Matoses, Diana-Carolina Romero-Mora, Vicente Faus-Llacer

University of Valencia, Valencia, Spain

**Introduction:** Orthodontic treatment provides the space and correct occlusion to choose the restorative material in order to minimize further

wear. Interdisciplinary treatments with feldspathic veneers create a balance between morphology, function and aesthetics.

**Method:** Female patient, 34 years old, with attrition of the incisal edges of the maxillary central incisors. An orthodontic treatment was conducted to intrude incisors, to move apically the dentogingival complex and restore the missing coronal tooth structure improving the patient's smile esthetics and a harmonious occlusion. After the orthodontic treatment sequential photographs were taken and a DSD was carried out for esthetic and structural pre-evaluation. A mock-up guided by the DSD was placed in the patient's mouth to evaluate the esthetic parameters. A conservative treatment with Feldspathic veneers (Noritake EX-3, Kizaevo, Japan) was planned on teeth 11-21 to create an anterior guidance and bring central incisors and gums to appearance and function with acceptable parameters. Afterwards a slight gingivoplasty was completed to correct hyperplasia caused by the orthodontia. Teeth preparation was carried out through the mock-up in order to be less invasive as possible and then final cementation was with resin (Light Calibra Esthetic Resin Cement, Dentsply, Caulk).

**Conclusion:** Management of interdisciplinary treatment leads to the prognosis of recurrence associated with orthodontic movements. That makes it possible to restore function and esthetics with a lasting and conservative approach. Feldspathic porcelain veneers provide esthetic value and are visually as close to natural teeth as possible.

## CC06

### Timing in an ortho-conservative-treatment in a patient with attrition due to overbite and decreased overjet

Vicente Faus-Matoses¹, Igancio Faus-Matoses²,¹, Carla García-Cuesta¹, René-Domingo Botello-Torres¹, Vicente Faus-Llácer¹

¹University of Valencia. Master in Restorative dentistry and Endodontics, Valencia, Valencia, Spain, ²University of Valencia. Master in Orthodontics, Valencia, Valencia, Spain

**Introduction:** Teeth wear can occur for different factors and even alter the patient's esthetics. A conservative management approach has been followed to preserve the esthetics in those patients using direct composites and the Dahl principle. Timeline in an interdisciplinary treatment is needed to obtain good results.

**Description:** A 27-years-old male came to the dental office complaining about sensitivity and discomfort in the anterior teeth. The clinical examination revealed dental wear involving palatal surface of anterior maxillary teeth and incisal edges of lower incisors as a result of a deep overbite and a decreased overjet. He also presented diastemas in the anterior maxillary teeth due to the small size of the lateral incisors. The treatment plan was:

First step: Increase the vertical dimension following the Dahl principle placing direct palatal composite veneers and creating a posterior open bite.

Second step: Subsequent extrusion of posterior teeth was achieved and aided with orthodontics. The incisal edges were maintained in the same position to preserve the patient's smile line and to avoid the creation of an inverted smile. After 15 months the overbite had decreased providing an adequate anterior occlusion.
Third step: incisal edges of the lower incisors and the upper diastemas were restored with direct composite.

**Conclusions:** It is important to know the correct timing in cases of interdisciplinary treatments. Localized anterior worn dentition with an intact posterior dentition is possible to manage in a conservative way creating interocclusal posterior space following the Dahl principle aided by orthodontics and the use of direct composites.

## CC07

### Conservative retreatment with biologically oriented preparation technique (b.o.p.t.), orthodontics and direct composites

Vicente Faus-Matoses¹, Ignacio Faus-Matoses²,¹, Ignacio Vazquez-Natividad¹, Vicente Faus-Llacer¹

¹University of Valencia. Master in Restorative Dentistry and Endodontics, Valencia, Valencia, Spain, ²University of Valencia. Master in Orthodontics, Valencia, Valencia, Spain

**Objective:** To describe a conservative approach using multiple restorative procedures including B.O.P.T. technique to re-establish function and periodontal health while aesthetics is improved.

**Methods:** A healthy 55 year-old female came to our dental office concerned about her periodontal health and oral aesthetics. The clinical examination showed:

- Inflamed gums in the anterior maxillary teeth due to the presence of splinted zirconia crowns with inadequate marginal fit from 3 to 3, which presented cracked cores.

- Overbite and attrition lesions in posterior occlusal surfaces and anterior incisal edges of mandibular teeth with crooked incisors and reduced vertical dimension as consequence.

The treatment plan would include an interdisciplinary approach combining orthodontics and restorative procedures. Vertical dimension was increased with direct posterior composites. Inferior incisors were aligned with orthodontics and restored using also direct composite restorations. Conventional crowns (horizontally prepared) were replaced by alumina crowns using vertical preparations in order to preserve maximum tooth structure.

**Results:** The use of a B.O.P.T. technique achieved an optimal gingival condition avoiding an excessive loss of dental tissue. The restorative and minimally invasive treatment was able to solve the esthetic, inflammatory and functional issues successfully.

**Conclusion:** It is possible with a conservative approach and B.O.P.T. technique to achieve an excellent esthetic level while preserving gingival health and maximum tooth structure.

## CC08

### Assessment of Patients’ Oral Health Related Quality of Life in Treated Hypodontia Patients

Motasum Abu-Awwad, Ken Hemmings, Saja Mannaa, Daljit Gill, Akil Gulamali

University College London - Eastman Dental Institute, London, UK
Hypodontia has a negative impact on patients’ oral health related quality of life (OHRQoL).

**Aims 1:** Assess OHRQoL of hypodontia patients after treatment at Eastman Dental Hospital (EDH)

2. Assess the associations between patients’ reported OHRQoL with clinical dental assessment, patients’ satisfaction with treatment provided and social factors 3. Compare the patients’ OHRQoL following treatment with the British public norms.

**Methods:** Hypodontia patients who finished their dental treatment at EDH completed a questionnaire incorporating the 16-item UK oral health related quality-of-life measure (OHRQoL-UK), a list of four questions about their satisfaction with treatment received and a comprehensive clinical assessment using modified USPHS criteria.

**Results:** The sample included 52 participants (22 males, 30 females; median age 28 years) who had completed treatment for at least 6 months (Range 6-60 months). Most participants reported high OHRQoL scores and satisfaction with treatment provided. Clinical assessment revealed 4 of the participants had complications requiring treatment. No association between the clinical assessment and participants’ reported OHRQoL scores was found (P = 0.15). Satisfaction with dental aesthetics and gender revealed a statistically significant association (P = 0.006 and P = 0.047, respectively). The OHRQoL mean scores of the sample were statistically significantly higher than the OHRQoL mean scores of the British public norms for most age groups (P < 0.05).

**Conclusions:** Satisfaction with dental aesthetics seemed related to high OHRQoL scores. Females tended to report higher OHRQoL scores than males. Hypodontia patients following treatment were likely to report higher OHRQoL mean scores compared to the British population.

## CC09

### Masking discolored enamel surface with opaquers and tints before direct composite veneering.

Orsalia Vjero, Andreas Spaveras, Maria Antoniadou, Maria Anagnostou
Dental School, Athens, Greece

**Introduction:** Conservative and esthetic treatment of a single discolored anterior tooth is a great clinical challenge. This discoloration can be caused by various reasons, including intra-pulpal hemorrhage, dental trauma and endodontic treatment. If a bleaching procedure cannot be implemented or has been tried out without satisfactory outcome, other conservative procedures should be considered, such as a direct composite veneering. The opaque shades of composite resins still have inherent limitations in their opacification ability, especially when increments are very thin. Thus, in order to match the chromaticity of the adjacent teeth, the use of opaquers and tints is suggested. These materials can effectively mask dark enamel surface, after minimal preparation. Then different composite layers can be stratified, emulating the natural dentine and enamel tissues according to the layering technique.

**Aim:** The description of opaquers and tints' use in masking discolored enamel surface, prior to direct veneering with composite resins in representative clinical cases.

**Case presentations:** In the first case, discolored enamel surface of the left lateral incisor was covered with a microfill pink opaque (Pink Opaquer, Cosmedent). In a second one, the right central incisor was veneered after applying a nanohybrid tint (Inspiro, Edelweiss). In both cases application of opaque and tints over the prepared enamel surface was made after the polymerization of the bonding agent. Veneering was performed with a
composite resin system (Filtek Supreme Ultra, 3M ESPE) with the layering technique.

**Conclusion:** Although opaquers can achieve satisfied aesthetic results their application is considered as a technically sensitive approach.

## CC10

### Evaluating quality of life in different groups of patients

Teresa Palomares-Muriana

Dentistry Faculty, Granada, Spain

**Objective:**

This study was a controlled clinical trial aimed to assess how loss tooth affect oral health-related quality of life (OHRQoL) comparing two groups of patients: removable denture patients and non-removable denture patients classified by Eichner Index using the Oral Health Impact Profile (OHIP).

**Methods:**

The Oral Health Impact Profile OHIP-14 and OHIP-20 (for removable denture patients) was used to assess subjects' quality of life. Responses for each item are on a 5-point Likert scale (0 = "never" to 4 = "very often"). All responses were summed to produce an overall OHIP score that could range from 0 to 56 (OHIP-14) or from 0 to 80 (OHIP-20), with high scores indicating poorer oral health-related quality of life.

Subjects were grouped into 3 groups by posterior occlusal contacts according to the Eichner Index.

**Results:**

The mean OHIP-14 score for group A was 8,86 (with 16 points highest score), for group B 20,62 (with 43 points highest score) and for group C was 17,50 (with 36 points highest score).

The average OHIP-20 score for group B was 17,67 (with 33 points highest score) and for group C was 50,22 (with 80 points highest score).

We observed higher scores therefore poorer oral health-related quality of life in C group- removable denture patients.

**Conclusions:**

Loss of occlusal contacts contributed to a poorer OHRQoL, even if the tooth/teeth were replaced by removable prostheses.

The use of conventional removable dentures brings negative impacts in the OHRQoL of patients which may have influenced the self-perceived discomfort with the prostheses.

## CC11

### Chairside-fabricated positioning stent for luting indirect restoration on a flat preparation: A case report

Joëlle Dulla, Adrian Lussi

University of Bern, Bern, Switzerland

**Objective:** The aim of this case report is to present a technique to simplify and quicken the luting of an indirect restoration on a flat preparation with precision and predictability.

**Case Report:** A 56-year-old male consulted for a cracked left maxillary first molar. Clinical and radiographic examination revealed that the tooth was necrotic. After endodontic treatment, a composite overlay was preferred because of the buccal-palatal fissure. This case report describes the use of a chairside-fabricated positioning stent for luting the restoration.

**Discussion:** Full cuspal coverage is advised when restoring pulpless teeth. Root posts are avoided whenever possible. The absence of a locked seating position for the indirect restoration on a flat preparation can render its luting difficult. The marginal fit of the restoration is important to its prognosis. When using dual resin cement, time is limited, but luting with filled composite can be challenging due to its consistency. In this report, the stent provided precise and predictable seating of the restoration as on the cast model. Removing the luting composite excess was easy. Minimal occlusal adjustment was needed. This technique was clearly advantageous in saving time and effort.

**Conclusion:** A positioning stent for the luting of an indirect restoration using filled composite was easily fabricated on the chairside on the cast model. The stent permitted fast, predictable and reproducible seating. Due to its design, luting composite excess was easily removed. The minimal occlusal adjustment required for the restoration was an indication of its precise seating. Stent design could be further improved.

## CC12

### 48 months clinical performance of two current glass-ionomer systems in a field study.

Thomas Klinke¹, Amro Daboul¹, Roland Frankenberger², Reinhard Hickel³, Reiner Biffar¹

¹Greifswald University, Greifswald, Germany, ²Philipps-University Marburg und University Hospital Gießen and Marburg, Marburg, Germany,

³University Munich, Munich, Germany

**Background:** The aim of this clinical field study was to evaluate the clinical performance of EquiaFil® with a nano-filled resin coating (Equia) and conventional Fuji IX GP fast® with LC coating (GPfast) according to the FDI restoration material evaluation criteria.

**Materials and Methods:** Equia (n1 = 515) and GPfast (n2 = 486) were used to restore permanent teeth; class I (n1 = 146/n2 = 166), II mo/od (n1 = 225/n2 = 211) and class II mod (n1 = 13/n2 = 21). Clinical examination, including photographs and stone casts, was carried out in a yearly-follow-up for 4 years by calibrated external examiners. Changes in aesthetic, functional and biological parameters (FDI_criteria: B5/B6/B8/B10/C11/C12/C13) over time were estimated with logistic mixed models adjusted for age, sex, fillings, patients and dentists.

**Results:** Both materials performed well in class I cavities, for class II mo/od, 16 fractures (GPfast) and 7 fractures (Equia) were observed. Odds ratios in adjusted random intercept models showed a protective treatment effect of Equia when placed within manufacturer's indication (odds ratio: 0.19) compared to GPfast. Filling size and surfaces was the most important component that affected clinical performance of both materials. Random intercept models adjusted for filling size showed approximately two times higher odds for 2-surface fillings within
and outside manufacturer's indication compared to fillings only within manufacturer's indications.

**Conclusion:** Both materials showed similar performance after 48 months in class I cavities. Within the manufacturer's indication, EquiaFil® showed a better overall performance with fewer failures in the follow-up intervals for class II (mo/od) fillings compared to GPfast. For better longevity, the manufacturers' recommendations have to be strictly followed.

## CC13

**Diagnosis and healing follow up of a cutaneous fistulous tract using 3-D images.**

Cristina González Losada¹, Alfredo Saralegui Calvo¹, Paula Saralegui González¹

¹University Complutense, Madrid, Spain, ²University Complutense, Madrid, Spain, ³University Autónoma, Madrid, Spain

**Introduction:** The use of CBCT in endodontics should be limited to the assessment and treatment of complex endodontic conditions such us diagnosis of wide radiolucency lesions with no evidence of limits, identified with conventional imaging.

**Clinical cases:** We show clinical situations in which CBCT has been necessary to confirm our diagnosis. Conventional intraoral radiography provides clinicians with high-resolution imaging that continues to be the front-line method for dental imaging but there are situations in which due to its two dimensions images we can't get information like CBCT units, which reconstruct the data to provide interrelational images in three orthogonal planes (axial, sagittal and coronal).

The clinical case is a female, 30 years old who presents a cutaneous fistulous tract located next to the chin. This patient was in orthodontic treatment and we confirm the negative vitality of the right central inferior incisive. The vitality test was normal in all the other inferior teeth. We confirm the lesion and the limit extension and bone damage in the CBCT.

We show the endodontic treatment in this teeth and the control radiographies, as well as the evaluation of the recovery bone after one year and its confirmation with a new tridimensional radiographic technique (CBCT).

**Conclusions:** CBCT has been definitive in this clinical situation to confirm lesion extension limits and bone damage. It is necessary nowadays in Endodontics using CBCT as a complementary method of exploration and diagnosis. It allows confirmation of the pathology as well as evaluation of the recovery.

## CC14

**10-year follow up of a case of Amelogenesis Imperfect restored free hand with resin composites**

L. Sebnem Turkun

Ege University School of Dentistry, Izmir, Turkey

Amelogenesis imperfecta (AI) is an inherited enamel dysplasia involving both dentitions with no other systemic effects. The hereditary pattern is autosomal or X-related dominant or recessive. Its prevalence is

approximately 1:14,000-1:16,000. It can be classified as hypocalcified, hypoplastic and hypomaturated according to clinical, radiological, histological and hereditary findings.

This clinical report presents a case of hypomaturated type AI in a 16-year-old young man that was successfully treated with different types of resin composites and followed-up for 10-years. The patient's anterior teeth were restored with Filtek A110 (3M/ESPE, USA) and the posteriors with Filtek Z250 (3M/ESPE, USA) resin composite systems and with the help of Palodent matris system (Dentsply, USA). The finishing and polishing of the restorations were performed with diamond burs, Enhance & PoGo polishing systems (Dentsply DeTrey, Germany).

The patient was recalled postoperatively every month for 6 months and then every 3 months for 2 years and then moved in another city for University education and did not attend his appointments. He came back 10 years later with a problem on his upper left canine. His oral hygiene was very bad, some marginal discolorations occurred on his anterior restorations but only 3 posterior restorations were lost. His impacted upper left canine teeth started to came in mouth. His oral hygiene was optimized, the posterior restorations refurbished/rebuild with a nanaohybrid resin composite G-aenial Posterior (GC, Japan) and the frontal teeth were re-restored again free hand with G-aenial (GC) a nanohybrid resin composite.

## CC15

**Minimal intervention dental treatment for elderly patient**

Sevil Gurgan, Zeynep Bilge Kutuk, Filiz Yalcin Cakir

Hacettepe university, Ankara, Turkey

**Purpose:** Minimal intervention dentistry (MID) is a philosophy of care that aims to conserve tooth tissues throughout a person's life with a modern medical approach to the management of caries, utilizing caries risk assessment, and focusing on the early prevention and interception of disease. The proportion of older adults in populations across the world is increasing, and this ageing population is going to present dentists with significant challenges. In this case presentation, minimally invasive restorative treatment of an elderly patient was demonstrated with four principals of MID.

**Method:** After clinical and radiographic examinations of a 76 year old male patient who was seeking oral care, potential caries risk factors were evaluated (1) by using saliva (Saliva-Check buffer, GC), bacteria (Saliva-Check Mutans Test, GC) and plaque analysis (Plaque Indicator kit, GC). Oral self-care, consist of toothbrushing twice daily with fluoride toothpaste was recommended. In addition to oral hygiene procedures, fluoride (MI Varnish, GC) and casein phosphopeptides-amorphous calcium phosphate (CPP-ACP) pastes (Tooth Mousse, GC) were applied to retard caries progression and remineralize dental tissue (2). Remineralization and restoration of cervical lesions were carried out to maximize the retain tooth structure more conservative and less invasive (3) with the use of flowable composite (G-aenial Flo, GC) and glass ionomer (Equia, GC). The patient was re-evaluated every 6 month (4) for the maintenance of oral status.

**Results:** Minimally invasive approach to restorative dental care would appear to be appropriate for older adults.
**Conclusion:** MID offers the dental professional working with older patients realistic, rational, evidence based options for treating oral disease.

## CC16

### A fiber rein-forced composite bridge for missing maxillary lateral incisor

Ali Alabas, Elif Aybala Oktay, Fulya Toksoy Topcu

Gulhane Military Medical Faculty, Department of Restorative Dentistry, Ankara, Turkey

**Objective:** The people with missing lateral incisors must be treated quickly to restore function and aesthetics. The loss of anterior teeth can be painful for patients, both psychologically and socially. A variety of a treatment options, from implant to conventional bridge prosthesis, can be used for the replacement of a missing anterior tooth. The fiber reinforced composite bridges are good alternative to conventional prosthetic techniques because of being a non-invasive or minimally invasive application with very little or no tooth preparation.

**Case Report:** A 22-year-old young woman was referred to our clinic for her missing maxillary left lateral tooth. We have decided to apply fiber rein-forced bridge to fill the gap.

**Result:** The treatment was completed in a one-visit appointment.

**Conclusion:** A fiber rein-forced composite bridge is generally less costly and provides immediate esthetic solutions then traditional prosthetic options. The anatomical layering technique provides natural opacity, transluceny and opalescence with using of different dentin and enamel composites to build up the composite pontic. But composites are brittle materials. Fiber reinforcing of a composite resin bridge increases the fracture toughness and resistance.

## CC17

### Aesthetic approach for bilateral peg shaped maxillary lateral incisors

Ali Alabas, Elif Aybala Oktay, Fulya Toksoy Topcu

Gulhane Military Medical Faculty, Department of Restorative Dentistry, Ankara, Turkey

**Objective:** Today, people especially young adolescents are paying more attention to their appearance ever before and their teeth are a key element in their personal appearance. Modern adhesive techniques are now used to add restorative materials to the tooth for the correction of unaesthetic tooth forms, tooth positions, dimensions, colors, and to close diastemata, to build out peg-shaped laterals and to change the tooth form of elements with an abnormal anatomical position.

**Case Report:** This clinical report describes aesthetic and preventive approaches for treatment of a patient diagnosed with bilateral peg-shaped lateral incisors. Direct composite veneers were applied to this case. Natural Look DFL (Rio de Janeiro, RJ, Brazil) composite laminate in B1 color together with 37% orthophosphoric acid Alpha Etch Gel and Alpha Bond (Rio de Janeiro, RJ, Brazil), all from the composite kit, were used for this purpose.

**Result:** An 18 years old girl has begun to smile easily without caring her teeth appearance.

**Conclusion:** Conical tooth anomaly is a hereditary and otosomal dominant disorder which usually effects the maxillary permanent lateral incisors and third molars. Generally, the affected teeth are smaller than normal sizes and usually show a conical form which may be peg, cylindrical, barrelshaped etc. This anomaly can give rise some physiological and psychological problems. Because of this reason, early diagnosis and treatments are important. For treatment of this anomaly, composite veneer restorations can be made and thus an ideal oral condition and pleasure of patient may be provide esthetically and functionally.

## CC18

### Treatmant of flourosis and enamel hypoplasia with direct laminate veneers

Ali Alabas, Elif Aybala Oktay, Fulya Toksoy Topcu

Gulhane Military Medical Faculty, Department of Restorative Dentistry, Ankara, Turkey

**Objective:** The defects caused by enamel hypoplasia and the discolorations caused by dental flourosis that occur at the anterior teeth can cause aesthetic problems. Because of aesthetic problems and decay rise, such cases must be urgently treatment. For the treatment of these cases, laminate veneer restorations may be a treatment option.

**Case Report:** In these two cases, enamel hypoplasia and flourosis was observed at two patients that presented to our clinic. The advantage of aesthetic, simply use and short treatment time, direct composite resin restoration application was decided to both patients. Natural Look DFL (Rio de Janeiro, RJ, Brazil) composite laminate in A1 color together with 37% orthophosphoric acid Alpha Etch Gel and Alpha Bond (Rio de Janeiro, RJ, Brazil), all from the composite kit, were used for this purpose.

**Result:** As a result of direct composite resin application, reached an acceptable aesthetic.

**Conclusion:** Enamel hypoplasia and flourosis, result in esthetic and even psychological problems. At the treatment of enamel hypoplasia and flourosis, from simple to complex tooth colored restorative materials, laminate veneer restorations and all ceramic restorations can be used. It should be aimed to choose the less harmful, the quickest and the most esthetic treatment method. Direct composite veneers are thought to be more conservative than prosthetic approaches.

## CC19

### Direct laminate veneers instead of orthodontics treatment

Ali Alabas, Elif Aybala Oktay, Fulya Toksoy Topcu

Gulhane Military Medical Faculty, Department of Restorative Dentistry, Ankara, Turkey

**Objective:** A few people are born with a perfectly aligned smile. If your teeth are crooked or misaligned, you may need to use orthodontics to improve the appearance of malposed teeth. However, some people are not enthusiastic about the idea of wearing fixed braces for an extended period of time. Furthermore, composite veneers can be used to fix minor misalignments in just a single appointment.
**Case Report:** In these two cases, class one malocclusion was observed at two patients that presented to our clinic. In accordance with the wishes of the patients, direct composite veneers were applied. Natural Look DFL (Rio de Janeiro, RJ, Brazil) composite laminate in B1 color together with 37% orthophosphoric acid Alpha Etch Geland Alpha Bond (Rio de Janeiro, RJ, Brazil), all from the composite kit, were used for this purpose.

**Result:** We have created the appearance of a straight, white, aligned smile.

**Conclusion:** The advantages of using direct laminate veneers to restore the teeth are many. In a short time very good aesthetics can be obtained, with minimal tooth preparation. And also they are becoming more popular as they are easy to repair. However the main disadvantages of them are discoloration, fractures and low resistance to wear. Furthermore, indirect composite laminate veneer restorations have better color stability due to polymerization outside of the oral cavity.

## CC20

### Some little aesthetic touches with composites to make you happy

Ali Alabas, Elif Aybala Oktay, Fulya Toksoy Topcu

Gulhane Military Medical Faculty, Department of Restorative Dentistry, Ankara, Turkey

**Objective:** Defects in the maxillary anterior teeth, such as fractures in teeth crowns, can present esthetic challenges. A treatment plan that can be completed in a single appointment is highly desirable such as these cases. Laminate veneers are restorations which are envisioned to correct existing discolorations, abnormalities and esthetic deficiencies. Direct laminate veneers have no need to be prepared in the laboratory and are based on the principle of application of a composite material directly to the prepared tooth surface in the dental clinic.

**Case Report:** A 21-year-old female with incisal edge fractures of maxillary central incisor and a 26-year-old female with enamel and dentin fractures of both maxillary central incisors were observed at two patients that presented to our clinic. Direct composite veneers were applied to both of them. Natural Look DFL composite laminate in A1 color together with 37% orthophosphoric acid Alpha Etch Gel and Alpha Bond, all from the composite kit, were used for this purpose

**Result:** The final result met the patient's expectations.

**Conclusion:** Usually because of difficulties with the final restoration of the treatment of fractured teeth, can be complicated. The systematic history and examination are very important in all cases of dental trauma treatments. It also shows that conservative management is possible or not. Direct and indirect laminate veneers, as esthetic procedures, have become treatment alternatives for patients with esthetic problems of anterior teeth in recent years. In deciding between treatment options, the cost, social and time factors have to be considered.

## CC21

### Only 30 minutes is sufficient for whiter teeth

Ali Alabas, Elif Aybala Oktay, Fulya Toksoy Topcu

Gulhane Military Medical Faculty, Department of Restorative Dentistry, Ankara, Turkey

**Objective:** Today beautiful smile with white teeth is one of the most important expression of a person. Nothing could be more desirable than a beautiful and white smile. Aesthetic dentistry, including tooth whitening, has increased in recent years. Dental bleaching is more conservative, quick, simple, and low cost approach to change the color of discoloured teeth. Vital tooth bleaching can be used to fix discolored teeth in just a single appointment.

**Case Report:** In these two cases, discoloration was observed at two patients that presented to our clinic. In office vital bleaching technique were applied for thirty minutes to get whiter teeth for both cases. As bleaching agent, Whiteness HP (FGM, Joinville, Brazil), containing 35% hydrogen peroxide was used.

**Result:** After 30 minutes bleaching treatment, whiteness was obtained which satisfied the patient.

**Conclusion:** In-office systems, typically 35% hydrogen peroxide whitening agent are used. Advantages include minimal dependence on patient compliance and immediate visible results, which satisfy patients who want to see quick results. Tooth sensitivity is the most common side effects in vital tooth bleaching. Usually the sensitivity was moderate and was more severe on the day of the gel application. With the addition of potassium nitrate-fluoride into bleaching agent, reduces sensitivity of bleaching.

## CC22

### Nonvital bleaching is enough to get a better color

Ali Alabas, Elif Aybala Oktay, Fulya Toksoy Topcu

Gulhane Military Medical Faculty, Department of Restorative Dentistry, Ankara, Turkey

**Objective:** In recent years, number of patients admitting to the dentist for a beautiful smile is increasing. Discolorations of nonvital teeth lead to esthetic problems since they can be easily distinguished in teeth. The reason for this is that they are usually asymmetrical. So they need to be treated.

**Case Report:** In this clinical study, 2 patients were treated using carbamide peroxide for intracoronal bleaching of maxillary santral incisor teeth discolored due to trauma and root canal therapy. As bleaching agent, Whiteness Super-Endo (FGM, Joinville, Brazil), containing 37% carbamide peroxide was used.

**Result:** Bleaching in both two cases was achieved in two days. The treatment with carbamide peroxide as regards the handling and application time proved advantages.

**Conclusion:** Discoloration may result from pulp necrosis, intrapulpal hemorrhage, pulp residues remaining after endodontic treatment, endodontic materials, resorption and aging for the treatment of non-vital teeth, the most conservative one is intracoronal bleaching technique. Most commonly used bleaching agent is Hydro Peroxide. The bleaching agents on the market generally contain carbamide peroxide (CP) or hydrogen peroxide (HP). CP solutions do not have a stable structure and they decompose to HP, carbon dioxide and urea in oral environment. Then bleaching process occurs with HP
## CC24

**Case series demonstrating poly-ether-ether-ketone (PEEK) framework RPDs in the rehabilitation of partially dentate patients.**

Zaid Ali¹,², Nicolas Martin¹,², Sarah Baker¹

¹University of Sheffield, Sheffield, UK, ²Charles Clifford Dental Hospital, Sheffield, UK

The use of poly-aryl-ether-ketones (PAEK) materials as metal alternatives in the aerospace, device manufacturing and medical fields has been in place now for over twenty years. The introduction of these materials to the dental market is a novel development in the last few years. Market driven and patient led pressures to replace non-precious metal materials in prosthetic dental devices may encourage clinicians to take up the use of this novel material in their clinical practice.

The proposed advantages of PAEK polymers as non-metal framework alternatives are, in addition to being non-metal; having a modulus of elasticity closer to that of bone thereby reducing stresses to abutments, high wear resistance, high strength-to-weight ratio, manufacturing predictability and a proven track record for biocompatibility.

One such PAEK polymer which has been CE marked for use in dentistry is the JUVORA™ Dental Disc. This is a poly-ether-ether-ketone (PEEK) disc that is milled to a digitally designed shape using either a scan of a working model or data from an intra-oral scan impression.

We present three cases of the use of the Juvora dental disc as a removable partial denture material in the rehabilitation of partially dentate patients treated at the Charles Clifford Dental Hospital, University of Sheffield. Early outcomes are considered and discussed.

## CC25

**Dental inlays using nano-hybrid composite. Do it yourself**

Sebastiana Arroyo Bote, Javier Martinez Mmartinez Osorio

Faculty of Dentistry Barcelona University, Barcelona, Spain

**Objective:** The aim of the study was to perform laboratory-free dental inlays using Nano-Hybrid Composite. (GrandioSO, VOCO)

**Introduction:** Increased life expectancy of our patients obliges us to perform minimally invasive reconstructive treatments and to using materials that offer the best properties. This study presents two clinical cases where the clinicians doing dental inlays without laboratory

**Clinical Cases:** Two patients with coronal destruction of 4.6, one vital and another endodontically treated.

Treatment begins with carious tissue removal, cleaning and cavity preparation. In the vital case, we perform a direct impression of the cavity. For the endodontically treated case, a cavity floor is made in the distal conduit to place a fiberglass pole. After testing and adjusting the post an impression is made

In both cases, we empty the prints and perform Nano-Hybrid Composite (GrandioSO, VOCO) inlays using layering technique and 20-second

polymerization cycles. We perform another 120-seconds polymerization cycle on the inner part of the inlays.

Finally, we model and polish the inlays and, after clinical test, we perform adhesive bonding and occlusal adjustment of the inlay.

**Discussion-Conclusion:** Dental reconstruction is one of the most important treatments in Conservative Dentistry because of the technical challenge of rebuilding the crown and the importance of the materials we use for it. Indirect treatment allows for a better handling and polymerization of composites, helping to improve their properties.

## CC26

**In case of one tooth absence, discoloration, and mobility, restorative treatment**

Ertürk Bilgec, Fulya Toksoy Topçu, Elif Aybala Oktay

Gulfane Military Medical Faculty, Department of Restorative Dentistry, Ankara, Turkey

The patients are gradually requesting to complete their procedures in one session. Although this request is not feasible in all procedures, thanks to fibre technology, one session bridge production has become available for ruling out the one tooth lack. In order for eradicating one tooth lack, it could be used in mobile teeth as splint, as well. In this case report, one tooth lack was eradicated with adhesive bridge strengthened with fibre while it was used as a fibre splint to reduce the mobility in the teeth of this region. The decays and discolorations of the anterior teeth were treated with composite laminate veneer.

49 year old male patient presenting with tooth decays, discoloration and lack of the right upper lateral tooth, referred to our clinic. In order for ruling out the tooth lack (Angelus Interlig, Londrina, PR, Brasil) glass fiber (Technical & General, London, England) flowable composite, A2 colored (Herculite XRV, Kerr, Scafati, Italy) composite and (Alpha Etch Jel, Rio de Janerio, RJ, Brazil) 37% orthophosphoric acid and (Optibond, Kerr, Scafati, Italy) bonding were used for bridge application. The fibre was fixed to the mobile teeth and used as splint. Composite laminate veneer restoration was performed on the anterior teeth with the same composite set.

Due to the fact that teeth, alveolar bones were inappropriate for implant or crown bridge prosthesis procedure, we tried to perform the procedure with the adhesive bridge strengthened with fibre. Due to the dental mobility, the fibre was also used as a splint. With the composite laminate veneers, the patient gained his good appearance. Such procedures provide an aesthetic and advantaged restoration to the dentists thanks to the features including economic, adhesive, and aesthetic, one session applicable, splint use, biocompatible and easy to repair.

## CC27

**Quick and alternative solutions for aesthetic expectations**

Ertürk Bilgec, Elif Aybala Oktay, Fulya Toksoy Topçu

Gulfane Military Medical Faculty, Department of Restorative Dentistry, Ankara, Turkey
With the introduction of developing fibre technology in the dentistry, one tooth lack recovery has become easy within a short period. Adhesive technology provided an economic restoration and it became an alternative to conventional methods. In this case report, it is reported that adhesive bridge strengthened with fibre for one tooth lack as well as discoloured and former restorations containing upper anterior teeth were exposed to composite laminate veneer restoration procedure.

38 year old female patient presenting with lack of right upper lateral tooth and discoloration in the teeth referred to our clinic. She reported that she had little time, and due to the economic reasons she requested us not to apply prosthesis or implant. As a result of intraoral and radiographic examination of the patient, adhesive bridge strengthened with fibre was used for eradicating the lack of tooth, and for dental discoloration and former restorations, composite laminate veneer procedure was decided to be applied. In order for ruling out the tooth lack (Angelus İnterlig, Londrina, PR, Brasil) glass fiber (Technical & General, London, England) flowable composite, A2 colored (Herculite XRV, Kerr, Scafati, Italy) composite and (Alpha Etch Jel, Rio de Janerio, RJ, Brazil) 37% orthophosphoric acid and (Optibond, Kerr, Scafati, Italy) bonding were used for bridge application and composite laminate veneers.

Adhesive bridges strengthened with fibre are economic, aesthetic, one session applicable, biocompatible and easy to repair provide the advantaged restoration to us.

## CC28

### Change the appearance in a session

Ertürk Bilgeç, Fulya Toksoy Topçu, Elif Aybala Oktay

Gulhane Military Medical Faculty, Department of Restorative Dentistry, Ankara, Turkey

In today's dentistry, patients want the processes without pain and in a short time. These requests have led the dentists to the short-term treatments Developments of composites present to dentists to make good restorations in a short time. In that case report, the esthetic problems solved in a session on the upper anterior teeth with caries and discolorations.

23 year old young male patient presenting caries and discolorations on upper anterior teeth referred to our clinic. He complained from the appearance. He can't smile comfortable. As a result of intraoral and radiographic examination of the patient composite laminate veneer procedure was decided to be applied. First we treated the caries then we prepared teeth for direct laminate veneer. We choosed the convenient colours as dentin and enamel and made the direct laminate veneers. A2 colored (Herculite XRV, Kerr, Scafati, Italy) composite and (Alpha Etch Jel, Rio de Janerio, RJ, Brazil) 37% orthophosphoric acid and (Optibond, Kerr, Scafati, Italy) bonding were used for composite laminate veneers.

The bonding agent systems and composites present us to restore teeth without microleakage and we can make good colour on teeth. The patients are happy about restoration finished in a session and good appearance.

## CC29

### An esthetic bridge in a session

Ertürk Bilgeç, Elif Aybala Oktay, Fulya Toksoy Topçu

Gulhane Military Medical Faculty, Department of Restorative Dentistry, Ankara, Turkey

Nowadays the dentists work fast and less harmful to answer the patients' expectations. Lack of tooth can be resolved with prothesis and implant but these treatment can't be made in a session. The fibre technology solve the time problem. In this case report, lack of the right upper canin tooth problem was solved with the fibre reinforced bridge in a short time.

36 year old female patient presenting with lack of right upper canin tooth referred to our clinic. She reported that she had little time, and due to the economic reasons she requested us not to apply prosthesis or implant. As a result of intraoral and radiographic examination of the patient, adhesive bridge strengthened with fibre was used for eradicating the lack of tooth. In order for ruling out the tooth lack (Angelus İnterlig, Londrina, PR, Brasil) glass fiber (Technical&General, London,England) flowable composite, A2 colored (Herculite XRV, Kerr, Scafati, Italy) composite and (Alpha Etch Jel, Rio de Janerio, RJ, Brazil) 37% orthophosphoric acid and (Optibond, Kerr, Scafati, Italy) bonding were used for bridge application. So we solved the patient's functional and esthetic problem in a session with the fibre reinforced bridge.

We used fibre in the bridge because of the patient's requests. This bridge technique isn't stronger than classic prothesis. But Adhesive bridges strengthened with fibre are economic, aesthetic, one session applicable, biocompatible and easy to repair provide the advantaged restoration to us.

## CC30

### Minimal invasive treatment to white spot lesion

Ertürk Bilgeç, Fulya Toksoy Topçu, Elif Aybala Oktay

Gulhane Military Medical Faculty, Department of Restorative Dentistry, Ankara, Turkey

Nowadays, people are getting more and more worried about esthetism. While solving the esthetic problems, it is crucial that the patients' teeth are given as less harm as possible. If patients' discoloration problems cannot be solved by using bleaching techniques, the dentists use restorative ways. In this case report the upper four anterior teeth are restored with composite after minimal preparation.

27 year old female patient presenting with tooth discoloration and cavities referred to our clinic. The patient stated that she didn't want any prosthetic restoration. After examining the patient, it was easily seen that the discoloration couldn't be removed with bleaching methods. We decided that the teeth was restored with composite to get the esthetism again. A2 colored (Herculite XRV, Kerr, Scafati, Italy) composite and (Alpha Etch Jel, Rio de Janerio, RJ, Brazil) 37% orthophosphoric acid and (Optibond, Kerr, Scafati, Italy) bonding were used for composite laminate veneers.
It was a good choice to prefer to restore the teeth with the composite due to the fact that the discoloration cannot be treat with bleaching and it will be harm to make prosthesis. To become better with the developing technology of composite offers opportunities for minimally invasive interventions to dentists. Therefore the patients' satisfaction increases.

## CC31

**A resin composite layering approach for solving complex class IV restorations: a case report.**

Romain Ceinos¹,², Marie-France Bertrand¹,²

¹Nice Sophia Antipolis University, UFR Odontologie, Department of Conservative Dentistry and Endodontics, Nice, France, ²Nice University Hospital, Pôle Odontologie, Nice, France

**Objective:** A 60-year-old patient consulted the Nice university hospital to get a cosmetic opinion. The aesthetic problems on maxillary incisors were complex and linked to fractured and decayed teeth, old infiltrated or misshapen composite resin restorations. The treatment involved the replacement of faulty restorations. The two options for restoring teeth were discussed with the patient:

- a direct composite layering, the benefits of which include easy repair and a more conservative approach

- an indirect restoration made-up by a ceramist, which provides greater color homogeneity.

The patient rejected this high-cost option and desired smile enhancement in the most minimally invasive manner.

**Methods:** Study casts were taken and mounted on a semi-adjustable articulator to achieve an aesthetic analysis. A diagnostic wax-up was carried out to simulate the teeth's shape and volume modifications. The patient accepted the treatment plan. Direct anterior restorations were made using a layering technique with Enamel Plus HRI® (Micerium®) and special attention was given to finishing adjustment. The procedure was performed under rubber dam isolation to ensure the control of moisture.

**Results:** The four maxillary incisors were restored with a natural look. The patient confirmed her satisfaction with the smile enhancement.

**Conclusion:** The aesthetic integration of a restoration remains a complex challenge especially as far as the anteriors are concerned. As composite resins are used for aesthetic enhancement, the procedure represents a valuable framework on which to develop a rich stratification of natural teeth colors that achieves the expectations of both patient and practitioner.

## CC32

**Additive restorations of anterior teeth: improvement of treatment planning trough Aesthetic Digital Smile Design**

Riccardo Tempesta

University of Turin, Turin, Italy

**Objectives:** This report deals with one case of additive restorations on anterior teeth to close diastemas and to modify teeth shape. The aim of

this case report is to show the importance of Aesthetic Digital Smile Design (ADSD) in treatment planning.

**Methods:** The patient was a 19-years-old female that decided to stop a complex treatment after 4-year. The upper anterior region presented 2.2 conoid and diastemas between 1.1,1.2 and 2.1. The initial treatment, planned by the orthodontist, provided the shape correction of 2.2. However, once the patient was visited in the Operative Dentistry Department, the patient was involved in the treatment planning with ADSD, that through a dento-facial analysis performs a digital project of the aesthetic treatment. The final aesthetic result chosen by the patient was realized on a gypsum model with wax, thus the dentist could obtain several silicon guides that are needful to replicate the ADSD result. Additive restorations were then performed following a standardized clinical procedure: field isolation through rubber dam; teeth cleaning with aluminium oxide sandblasting; etch-and-rinse adhesive system application; direct additive restorations were performed using Clearfil-ES2 in an incremental layering technique with the help of silicon guides; interproximal contacts were created with shaped acetate matrices.

**Results:** 7 days and 12 months follow-up showed perfect aesthetic result and complete patient satisfaction.

**Conclusions:** Direct additive restoration can be a conservative choice for diastemas closure and tooth shape modification. Nowadays ADSD is fundamental to decide with patient its aesthetic restoration and to guide the dentist in performing it.

## CC33

**Open apex necrotic treatment options. Revitalization versus MTA apical barrier.**

Cristina González Losada¹, Alfredo Saralegui Calvo¹, Vicente Vera González¹

¹Complutense University, Madrid, Spain, ²Complutense University, Madrid, Spain, ³Complutense University, Madrid, Spain

**Introduction:** Calcium hydroxide has been considered the gold standard when choosing a material to induce apical root closure. After Andreasen publication's about decreased resistance to fracture of immature teeth after filling with calcium hydroxide, other treatment options had to be considered.

Actually open apex treatments are MTA apical barrier or “Revascularization technique”, described by Trope, also named “Revitalization”.

**Clinical cases:** We show different treatment options depending on the apex size and the age of the patient.

**Case 1:** Central incisor, ten years old patient with a non-vital immature teeth cylindric canal, not wider than 1,1 mm. In this case an apical MTA barrier was created to seal the apex successfully.

**Case 2:** Eight years old patient with a central incisor traumatically injured. The open apex is wider than the case described before eight. Better option to indicate a “revitalization”.

**Case 3:** Forty years old woman with open necrotic reabsorbed apex. An apical barrier with MTA was indicated due to age of patient and its apical anatomy.
In all these clinical cases radiolucencies were healed and clinical symptoms were resolved but only in Case 2 roots continued to develop.

**Conclusions:** Open apex necrotic teeth options are the creation of an apical barrier, the revitalization technique or both in case of failure of the last option.

Revitalization must be considered the preferred option in recent days as it can help to improve the prognosis of necrotic immature teeth by strengthening dentinal walls. It reduces risk of root fracture for now.

## CC34

### Conservative dentistry in provisionalization and progressive loading

Javier Martinez Osorio, Sebastiana Arroyo Bote, *Esther Lazaro*, Esther Berastegui Jimeno

*Faculty of Dentistry. Barcelona University, Barcelona, Spain*

**Objectives:** The aim of this study is to show the use of composites, glass-fiber reinforced with composite, adhesives and resin cements in provisionalization and progressive loading in patients undergoing dental rehabilitation.

**Clinical Cases:** Clinical cases of direct clinical reconstruction in patients with aesthetic and functional needs are presented. We perform rehabilitations of teeth within the incisor canine group using glass fiber-reinforced composite. The different opacities and effects of composites are particularly suitable for leading-edge aesthetics to treat urgent problems and/or when we need time to work on a definitive treatment.

We used conservative materials in the rehabilitation of a patient who had lost an anterior tooth in a traumatic situation. In the moment of the extraction we replayed the tooth using conservative techniques and materials. This treatment maintained the aesthetic appearance of the patient during the period in which the tissues healed. With another patient we used these materials during the period of osseointegration of implants to maintain aesthetic appearance and apply progressive occlusal forces over the implant.

**Discussion and Conclusions:** The aesthetic needs of today's society require us to provide immediate solutions for patients. The aesthetic adhesive materials allow the clinician to restore the aesthetic function of teeth immediately. The patients can have these treatments for a relatively long period in order to give sufficient time to study each case and provide definitive solutions. Composites with different densities, adhesives, glass-fiber reinforced with composite, and resin cements are suitable to solve these aesthetic cases.

## CC35

### Tridimensional Radiology applied to the treatment of calcified canals in Endodontics

Cristina González Losada¹, Alfredo Saralegui Calvo¹, Paula Saralegui González¹

¹Complutense University, Madrid, Spain, ²Complutense University, Madrid, Spain, ³Autonoma University, Madrid, Spain

**Introduction:** CBCT is a 3-D technology device, derived of Computer Tomography technology, whose main advantages are its reduced economic cost and radiation exposure.

Endodontic therapy depends on diagnosis radiographs and image guided treatment. Periapical and panoramic radiography have been supplemented by the introduction of limited field of view (FOV) high resolution CBCT, allowing three dimensional assessment of lesions, root canal morphology and anatomy.

Periapical radiographies allow mesio-distal adjustments during endodontic treatment but if we need confirmations of the canal position in a sagital (vestibule - palatal axis) we must resort to the use of 3D images.

**Clinical cases:** We show two clinical cases of calcified canals which made necessary an intraoperatory CBCT (Kodak 9000) to locate the canal position. In both patients periapical radiographies were not enough to place its position in a sagital axis, so a further tridimensional image testing was necessary to stablish a proper and accurate diagnosis.

Sequence or conventional and tridimensional images are describes in both cases.

**Conclusions:** Use of CBCT in Endodntics is limited to complex clinical cases when conventional radiography methods do not allow clinicians to establish a concludent diagnosis. This device is also useful during the endodontic treatment, especially in case of calcified canals when the determination of canal spatial situation is necessary.

This technique offers the possibility to analyze multiple section of the tooth in three planes so it helps to interpret and understand images and avoids the risk of perforations during the canal location phase.

## CC36

### Subcutaneous emphysema as a complication of endodontic treatment.

Fawad Amin

*Bristol Dental Hospital, Bristol, UK*

**Background:** Subcutaneous emphysema is rarely encountered in endodontic practice and consequently there is a dearth of information in the dental literature about this complication.

Subcutaneous emphysema is defined as the abnormal presence of air in tissue spaces. It arises when air is forced, under pressure, into the subcutaneous fascia leading to a sudden onset of soft tissue swelling. Introduction of air via the air-driven hand piece during surgical removal of impacted teeth is the most common cause of subcutaneous emphysema. Less commonly, it results from nonsurgical dental procedures including root canal treatment.

In most cases emphysema during root canal therapy resolves spontaneously after few days. However, it can be a frightening and unpleasant experience for both patient and dentist.

**Observations:** During re root canal treatment of the UR1, the patient experienced discomfort and swelling around her right
eye. This eventually resulted in her being unable to open her right eye. Most probably compressed air from the air syringe entered through the patent canal and spread along the facial planes into the periorbital space.

She was referred to an ophthalmologist who confirmed the diagnosis of periorbital emphysema. The patient was successfully treated with oral antibiotics and made an uneventful recovery.

**Conclusions:** Dentists should be aware of subcutaneous emphysema and its presentation. It is characterised by sudden onset of soft tissue swelling, associated with crepitus, during or shortly after the procedure. The majority of cases are managed conservatively. Patients should be reassured and advised as to the nature of emphysema.

## CC37

### A clinical complication of fiber-reinforced ribbon-composite provisional fixed partial denture of an adolescent patient

Derya Merve Halacoglu, Duygu Tuncer, Burcu Oglakci, Neslihan Arhun
Baskent University, Ankara, Turkey

**Background:** Treatment of adolescent patients with a missing incisor may be compromising because implants cannot be placed until craniofacial growth is complete. Fiber-reinforced ribbon-composite fixed provisional partial dentures can be used for the replacement of the missing teeth. Since the craniofacial growth continues in transverse, sagittal and vertical directions, regular control appointments must be managed to check the alveolar ridge/gingival level in the pontic area. This case report describes a clinical complication of fiber-reinforced ribbon-composite fixed provisional partial denture of an adolescent patient with a trauma originated missing incisor.

**Materials and Methods:** A 14 years old male patient who had attended to Baskent University in 2010, had a traumatic dental injury in #21 tooth which was extracted. Afterwards the missing tooth was replaced with a fiber reinforced ribbon-composite fixed provisional partial denture with patient's tooth as pontic until the definitive implant supported single-tooth prosthetic rehabilitation and the family was asked to visit every six months regularly.

**Results:** The patient didn't attend to the control appointments until the provisional denture's failure and the harmony between pontic tooth and the alveolar ridge/gingiva was severely compromised after 4 years.

**Conclusion:** If the goals of treatment favors fiber-reinforced ribbon-composite fixed provisional partial denture use before skeletal maturation, attention must be given to prosthesis design. Regular control appointments of alveolar ridge and pontic design must be managed and pontic tooth must be re-shaped to accommodate physiological soft and hard tissues in accordance with the skeletal growth to ensure esthetic future single implant supported prosthetic rehabilitation.

## CC38

### Management of the fractured and dehydrated tooth fragment

Derya Merve Halacoglu, Duygu Tuncer, Neslihan Arhun
Baskent University, Ankara, Turkey

Reattachment of the fractured and dehydrated tooth fragment should be considered as a first treatment choice and it is a valid alternative to a composite resin restoration. This case report presents the restoration of a fractured maxillary central incisor by reattaching the dehydrated tooth fragment.

A 17 years old male patient attended to the Baskent University, Restorative Dentistry department with the complaint of the fractured tooth (#11) and the fractured tooth fragment was kept in dry conditions for 5 days. After clinical and radiographic examinations, discolored composite resin restorations were noticed on #11 and #21. The fractured tooth and the fragment were acid etched with %37 phosphoric acid and then rinsed with water, dried gently. The bonding agent (Adper Single Bond-2, 3M ESPE) and flowable composite resin (Clearfil Majesty-A2, Kuraray) were applied without light curing on fractured tooth and fractured fragment. The fragment was carefully repositioned to the fractured tooth gently with finger pressure and light cured for 20s twice. After reattaching the fragment, discolored composite resin restorations were removed and new restorations were done with the same adhesive system and a nanohybrid composite (Spectrum TPH-A2, Dentsply) and finished-polished with finishing/polishing disks (Sof-Lex, 3M ESPE). Finally the reattached fragment was whiter than tooth but the white color was compensated after 1 week service in the mouth by rehydration. Restoration of the tooth by reattaching the original dehydrated fragment and gaining its natural color on the mouth is the best way of treatment in esthetic, conservative and economic point of view.

## CC39

### Conservative treatment of patients received head and neck radiation therapy – Protocols and clinical cases

Angeliki Karveli, Elissavet-Maria Tagka, Dimitris Kambouropoulos, Afrodite Kakaboura
Dental School of Athens, Athens, Greece

Patients, who receive anti-neoplasmatic therapy, usually present symptoms in the oral cavity such as oral mucositis, xerostomia and dental caries. Concerning dental caries, these patients are considered as high-risk patients. The management of these patients should begin before the therapy with treatment of all the dental problems and with intense preventive protocols, which are customized according to the type and phase of their anti-neoplasmatic therapy. Lastly, a strict recall system during and after the therapy is followed in order to monitor the changes in the oral cavity and deal with possible implications. However, even after application of this protocol, excessive loss of dental tissues due to caries is a common phenomenon. In addition, severe trismus due to surgical procedures or fibrosis of the masticatory muscles often reduce the mouth opening and further complicate the treatment procedures of the dental lesions. Furthermore, due to their serious health problems, a high percentage of such patients are left without specific dental care. As a result, extensive dental caries cause remarkable difficulties for tooth restoration. Even more, technically easy, less time-consuming and low-cost treatment plans are necessary for the most of the patients described.

In the current study, specific protocols regarding the prevention of dental caries which should be applied before, during and after the anti-neoplasmatic therapy will be reported. Furthermore, the step by step clinical conservative approach with resin composites for tooth rehabilitation in representative cases of patients who received anti-neoplasmatic therapy and were suffering from extensive dental caries will be presented.
## CC40

**A magical touch of cryotherapy on oral leukoplakia, a case report**

Sencer Secer¹, Didem Dincer², Hilal Ozturk³, Necdet Dogan¹, Hasan Ayberk Altug¹, Metin Sencimen¹, Tamer Zerener¹

¹Oral and Maxillofacial Surgery Department, Gulhane Military Medical Academy, Ankara, Turkey, ²Dermatology Department, Gulhane Military Medical Academy, Ankara, Turkey, ³Oral and Maxillofacial Radiology Department, Gulhane Military Medical Academy, Ankara, Turkey

**Aim:** Oral leukoplakia (OL) is a relatively common and a potentially malignant white lesion of the oral cavity. Tobacco and alcohol misuse are significant risk factors for the development of OL. The presence and degree of dysplasia are important diagnostic and prognostic criteria for OL. There is a lack of consensus on the most appropriate method of OL management. Cryotherapy is a frequently used method with promising results, that locally destroys lesion tissues by freezing in situ. In this case we aimed to show the steps of healing OL with cryotherapy.

**Case:** A 48 years old female heavy smoker patient was admitted to our clinic with a painless but a few stinging white plaque like lesion on all over her lower side of tounge and lingual side of alveolar crest between molars. An incisional biopsy was done on the lingual area and the patological report was orthokeratotic type leukoplakia with mild degree dysplasia. Complete excision was not possible due to the damage risk on salivary gland, lingual nerve and vessels, than we decided to apply cryotherapy.

**Results:** After cryotherapy treatment which was maintained for 9 months the lesion was disappeared without any complaint and any possible surgical complications.

**Conclusion:** Complete excision of high-risk lesions is recommended in suitable cases, besides careful selection of patients, cryotherapy is a simple, safe, easy, conservative, and acceptable treatment modality for treating OL. Specialists should closely follow up these patients with OL for life, like as we are going to do in this case.

## CC41

**Restorative Clinical Case (Conservative, Periodontics, Oral Surgery, Prosthodontics)**

Steve Conteh

Kings College London, London, UK

A 31 year old male attended the Primary Dental Care Clinic as a new patient for an oral health assessment 3-4 years since his last oral health assessment in the UK.

Upon comprehensive history taking, clinical examination and special testing the patient was diagnosed with:

- Generalised Moderate Chronic Periodontitis

- Dentine hypersensitivity most likely from TSL Tissue Surface Loss (TSL)

- Erosion + Attrition of maxillary anterior teeth-possibly due to Gastro-Oesophageal Relux Disorder (GORD) and reduction in posterior support

- Caries in UR7(mesial) UR3(distal) and UL5(mesial) Secondary Caries (UR5 and 6)

- Fractured LL5(distal), UR 5 and 6(occlusal)

- Unrestorable retained roots (UL4 and UR4)

A plan was put in place to first acheive stabilisation from active pathology. This involved significant prevention and intervention.

Having achieved stabilisation in dental health, through repeated preventative and interventive means, we were able to discuss definitive treatment option. All options appropriate to this case were discussed, together with their risks, benefits, length of treatments and what to expect. The patient was also informed of the consequence of no treatment.

We came to a suitable agreement on the definitive treatment to be embarked upon.

Definitive treatment was completed with a very favourable outcome that both the patient and I were very pleased with. The patient will continue regular periodontal maintenance of a few sites with appropriate changes being made to recall and intervention as indicated by examination result.

I am most pleased with the improvement in periodontal health as we would not have been able to build on pathological foundations. Work completed by myself with nurse assistance.

## CC42

**Management of severe tooth wear and occlusal collapse using composite build-up and overdenture**

Hayder Ameer¹,²

¹Guy's and St Thomas' NHS Trust, London, UK, ²Peninsula Dental School, Plymouth, UK

This is a clinical presentation illustrating the restorative management of a patient with severe tooth wear resulted from bruxism. 62 year old patient presented with severe wear of anterior teeth (grade 3 Smith & Knight index), loss of posterior support, and reduced occlusal vertical dimension (OVD).

The aim of the treatment was to increase the OVD in a reversible manner. Comprehensive clinical assessments were carried out using articulated study models in retruded position to construct diagnostic wax-up prior to the start of treatment.

Indirect composite build up was used to increase the occlusal dimension by 4mm. This was well tolerated by the patient as he had an original freeway space of 8mm. Severely worn upper anterior retained roots were root canal treated to maintain alveolar bone and preserve the proprioceptive capacity of periodontium. They were also fitted with gold copings to improve the stability of an overdenture. Upper (over-denture) and lower partial cobalt chromium dentures were constructed in the newly organised intercuspal position.

This treatment was successful in restoring the dentitions' form and function. The patient was reviewed in three monthly basis in which topical fluoride varnish was applied. He was also prescribed 5000ppm of sodium
flouride toothpaste. Clinical photographs and study models were used to monitor the patient's tooth wear.

This case was complex and presented with many challenges. However, through continual discussions with the patient and the technicians, a comprehensive, sequential treatment plan, with alternative treatment options was tailored to his needs.

## CC43

### Pulp vitality preservation in traumatic avulsion of maxillary central incisor: case report with 2-year follow-up

Claudio Ghiberto, Riccardo Tempesta, Elio Berutti, Nicola Scotti
*University of Turin, Department of Surgical Sciences, Dental School, Turin, Piedmont, Italy*

**Objectives:** This clinical case shows the clinical procedure and 2-year result for the resolution of a severe dental trauma.

**Methods:** The patient, a 21-years-old female, was visited in the Department of Operative Dentistry of Turin after a dental trauma, which occurred 20h before. The patient showed a partial avulsion (6mm out of alveolar bone) of 1.1 and coronal fractures on 1.1 and 2.1. After clinical and radiographic exams, which showed any bone fractures, 1.1 was immediately replaced in the correct position and splinted with glass fibres (GrandTec, Voco) to adjacent teeth. Teeth vitality was evaluated with thermal and electric pulp tests every 7days for the following weeks. After 2 months teeth were still vital, thus splint was removed and tooth mobility was absent. Then, 1.1 and 2.1 fourth-class composite restorations were performed as follow: field isolation through rubber dam; enamel margin bevelling and finishing; etch-and-rinse adhesive system application; execution of direct restorations with Asteria (Tokuyama) in an incremental layering technique with the aid of buccal and oral silicon guides; finishing and polishing with fine-grit burs and silicon points. Final radiographs were taken and follow-up visits were planned.

**Results:** 6, 12, 18 and 24 months follow-up showed teeth vitality and stability maintenance, soft tissue healing and perfect composite integration.

**Conclusions:** Immediate tooth repositioning and stable splint are key factors in the treatment of dental traumas, above all when severe damage such as avulsion (partial of complete) happens. Further follow-up are necessary to verify treatment behavior overtime.

## CC44

### Diastema closure treatment with direct resin composite restoration: clinical reports

Solen Gunal, Zeynep Batu
*Department of Restorative Dentistry, Istanbul Aydin University, Istanbul, Turkey*

**Objective:** Shape, position, size irregularities and gaps between anterior teeth are major aesthetic problems for patients. Adhesive systems enables clinicians to recontour teeth minimally or non-invasively with the aid of

direct composite resin buildups to form a better smile. The aim of this study was to evaluate the clinical performans of direct composite restorations in diastema closure treatment at 6 months follow up.

**Methods:** A total of 82 composite restorations of 22 patients applied for diastema closure included in this study. All teeth were restored by one operator with Filtek Z250 universal restorative material (3M ESPE, USA) and dentin bonding system Clearfil S³ (Kuraray, Japan). All of the restorations were then polished with Sof-Lex finishing and polishing systems (3M ESPE, USA) from coarse to fine grits. The patients were recalled after 6 months and the restorations were evaluated using the modified USPHS criteria for retention, color match, marginal discolorization, marginal adaptation, surface texture and anatomic form.

**Results:** At the 6 months follow up all restorations were in situ, no complete loss was recorded and most of the restorations displayed excellent or good quality.

**Conclusion:** Direct composite restoration is an effective treatment when minimally invasive tooth preparation, economical and aesthetical treatment is required for closing diastemata.

## CC45

### Direct composite veneers on severely eroded anterior teeth: a case report with 1 year follow-up

Alessandro Pezzana
*University of Turin, Turin, Piedmont, Italy*

**Objectives:** This report deals with one case of direct composite veneers on anterior teeth with severe acid erosion. The aim of this case report is to understand clinical possibilities of extended

**Methods:** The patient was a 32-years-old female who presented maxillary anterior teeth with erosion of the whole buccal enamel. The patient wishes were to smile again and to reduce sensitivity to thermal stimulus. She previously visited several dentists, but she cannot afford expensive treatments because of low-economic conditions. The patient was then treated in the Operative Dentistry Department with direct composites veneers. At the first appointment, impressions were taken and a wax-up of the ideal teeth shape was performed, thus the dentist could obtain several silicon guides that are needful during composite layering. Additive restorations were then performed following a standardized clinical procedure: field isolation through rubber dam; teeth cleaning with aluminium oxide sandblasting; etch-and-rinse adhesive system application; direct additive restorations were performed using Clearfil-ES2 in an incremental layering technique with the help of buccal and oral silicon guides. Finishing and polishing procedures were then performed with fine-grit burs and silicon points. Final rx were taken and follow-up visits were planned.

**Results:** 7 days and 12 months follow-up showed perfect aesthetic and functional results and complete patient satisfaction.

**Conclusions:** Direct additive restoration can be a conservative and low-cost choice for direct composite veneers. With this technique an aesthetic smile improvement and sensitivity disappearance were obtained. Further follow-up are necessary in order to understand treatment behavior overtime.
CC45

Neurorehabilitation with Low-Level Laser Therapy after retromolar
ridge bone graft: A case report

Despoina Chatzistavrianou, Lochana Nanayakkara

Barts Health NHS Trust, The Royal London Hospital, Turner street, Whitechapel, London, E1 1BB, UK

A wide variety of dental procedures can result to inferior alveolar nerve
injury. Nerve impairment clinically is reflected as total loss of function,
mild and transitory reduction of the tactile and thermal acuity or neuro-
genic disturbance. Although, more rapid recovery is noticed the first six
months post-injury, late recovery may occur.

This case report presents a patient with numbness in the area of the
inferior alveolar nerve distribution after a bone graft procedure from the
left retromolar ridge that partly resolved with the application of low-level
laser therapy. Patient was treated with low level laser therapy (3 Watt for 1
min) in the left chin/lip, left mandible, left zygoma and left buccal sulcus
once a week in 8 sessions. Subjective and objective evaluations were
completed before and after the laser treatment and confirmed improve-
ment in the sensation of the left site after the laser therapy.

Prevention of nerve damage in oral and maxillofacial interventions is the best treatment. Low level laser therapy can offer alternative treatment possibilities by improving treatment outcomes and reducing associated complications in a wide range of oral and maxillofacial interventions. Although, there is paucity of evidence on the efficiency of low level laser therapy in neurorehabilitation of inferior alveolar nerve, patients reported improvement in sensory function after the application laser treatment. Low level laser treatment is a viable treatment modality in case of paraesthesia and nerve damage taking into consideration its non-invasive nature.

Dental Education (DE)

DE01

Bibliometric study of articles about DMF indices and ICDAS pub-
lished on pubmed

Adjaratou Wakha Aidara¹, Christian Mesenge², Denis Bourgeois³

¹Cheikh Anta Diop University, Dakar, Senegal, ²Université du Québec en Abitibi-Témiscamingue, Québec, Canada, ³Université Claude Bernard Lyon 1, Lyon, France

**Background:** Bibliometrics is an important tool in decision-making's of research policy. The evolution of clinical and epidemiological concepts has led to a new paradigm in cariology. However, few bibliometric studies are conducted on epidemiological indices used on Cariology. This transverse study aims to identify and to make a comparative bibliometric analysis of articles dealing with the two indexes of caries mainly used during the last ten years.

**Methods:** the methodology consisted in a bibliometric research of articles focused on DMF and ICDAS indices published on PubMed without limitation of dates and a bibliometric analysis of the results of bibliometric research.

**Results:** The results showed that few bibliometric studies (4 items) dealing with cariology were published. Two thousand and fifty-

five (2055) articles on DMF and 91 articles on ICDAS were
identified in PubMed. Thirty-six years separates the first publica-
tions on DMF and those on ICDAS. For DMF, the publication
ratio was 6 articles by newspaper and 46.7 articles per year while
for ICDAS it was 2.8 articles per newspaper and 11.4 articles per
year. The bibliometric analysis revealed that the authors published
the same types of articles for the DMF and the ICDAS. Most of
the published articles were comparative studies (41.6%), clinical
trials (13.8%), validation studies (10.6%) and randomized clinical
trials (10.2%).

**Conclusion:** The results showed the need for further study by exploiting other types of bibliometric data to build a comprehensive database that will help for clinical and epidemiological decision-making based on the evidence in the field of Cariology.

DE02

Effect of Education on Dental Students' Attitudes on Caries
Prevention

Hande Sar Sancakli¹, Lezize Sebnem Turkun², Yusuf Ziya Baymdr³,
Cemal Yesilyurt⁴, Gamze Yildirim², Merve Iscan³, Tugba Serin Kalay⁴,
Sevda Ozel Yildiz⁵, Taner Yucel¹, Esra Yildiz¹

¹Istanbul University Faculty of Dentistry Department Of Restorative Dentistry, Istanbul, Turkey, ²Ege University Faculty of Dentistry, Department Of Restorative Dentistry, Izmir, Turkey, ³Ataturk University Faculty of Dentistry, Department Of Restorative Dentistry, Erzurum, Turkey, ⁴Karadeniz Technical University Faculty of Dentistry, Department Of Restorative Dentistry, Trabzon, Turkey, ⁵Istanbul University Faculty of Medicine, Department of Isthematics, Istanbul, Turkey

**Aim:** Dental caries remains as the most common chronic disease which can be prevented to decrease the prevalence and severity. The contemporary dentistry approach requires caries risk assessment and prevention which is already included in the undergraduate curriculum. The aim of this multi-centered questionnaire was to assess the effect of caries prophylaxis education within the dental curriculum on the knowledge, attitudes, and intended behaviors in caries prevention of dental students from 4 dental schools located in different regions of Turkey.

**Materials and methods:** 281 fifth-year students were included in a thirty-seven-itemed written opinion and knowledge regarding a caries prophylaxis based questionnaire. Data were gathered and the total frequency was determined.

**Results:** 95% of the students reported that caries can be inhibited by prophylactic measures performed at the 6-12 months recalls. 96% evaluated fissure sealants applied on the first and second molars as an effective method to inhibit caries whereas 60% would prefer fluoride gel as first choice. 86% of the students would recommend sugar-free chewing gums with an increasing rate and 85% considered that snack meals increases caries risk. 43% of the students reported that they would use caries diagnostic tests for the high-caries risk patients while only 14% would use them for all. 84% would recommend routine check-ups while 78% would apply fluoride gel as a primer preventive measure.

**Conclusion:** The effect of the education regarding the caries prevention awareness seems to raise and increase the attitudes of dental students toward implication of preventive techniques in their daily practice.
## DE03

**The application of haptic simulation in manual dexterity performance in first dental students.**

Anuradha Polster, Michael Francis Burrow, Matthew Hopcraft
*The University of Melbourne, Victoria, Australia*

The aim of this study was to evaluate manual dexterity performance and development of 70 first year Doctor of Dental Surgery students at the Melbourne Dental School using MOOG Simodont haptic dental trainers in association with traditional preclinical training on phantom head manikins.

Students performed a series of gradually more complex 3D tasks that simulated cutting shapes encountered in Operative Dentistry on the haptic dental trainer. The Simodont is able to generate reports on a range of parameters, including the number of attempts for each task, the total ‘drilling’ time, the percentage of the 3D target shape removed, and the percentage removed beyond the leeway space (greater than the desired shape) around the task. The parameters generated from the reports were then compared with assessment scores from the phantom head exercises later in the first year. Phantom head tasks included various cavity preparations in plastic teeth. The project was approved by the University Humans ethics committee; signed informed consent was obtained from participants.

It was shown that as students progressed on the more complex Simodont tasks their manual dexterity improved. A few students showed continual difficulty in completing the complex tasks even after extended practice. It was also demonstrated that level of performance on the 3D haptic tasks was a good predictor of later performance in phantom head tests.

It was concluded that the SIModont may be a useful tool for early identification of students who may encounter difficulties in developing dexterity skills.

## DE04

**CAFS - Enhancing teacher feedback and learner reflection in clinical dental education**

Upen Patel, James Kelly, David Attrill, Deborah White, Giles Perryer
*School of Dentistry, University of Birmingham, Birmingham, UK*

Educating clinical dental students in a busy multi-chair clinic is challenging, and time pressures can often result in clinical educators becoming mere supervisors. CAFS (Clinical Assessment and Feedback System) provides a tablet-based transparent quality assurance tool that ensures educators provide learners with (recorded) constructive feedback for each clinical session, and that learners consider the feedback received, and record their reflections. A typical clinical learning episode using CAFS would have the learner record the procedures they had undertaken. The patient then has the opportunity to provide confidential feedback based on their experiences with the dental student. The educator records performance grades (assessment) and feedback into the system. Finally, the learner is expected to record their reflections and learning points from their experience of treating the patient. This final step allows the learner to achieve a higher level of learning.

Having educator feedback stored electronically and being available online allows the learner to reflect on the complete learning process when they wish rather than at the time of the learning episode. The learner is also able to check their ranking within the cohort, putting their clinical progress into perspective. Holding the information in this way facilitates educator calibration and ensures transparency of information between all educators and learners. This system has shown to increase the quality of feedback by educators. Learners have also demonstrated an increase in reflective - higher-level - learning. We believe this system significantly enhances clinical dental education and is the future for effective learning in a clinical environment.

## DE05

**The CAD/CAM unit in Paris Descartes University: for and by students**

Anne-Margaux Collignon¹,², Claudine Wulfman¹,³, Boris Jakubowicz¹,⁴, Mathieu Derbanne¹, Bruno Zamansky¹, Nicolas Lebon¹,⁵, Stephane Le Goff³,⁴, Aurelie Dubroca¹,³, Laurent Tapie¹,⁵, Jean-Pierre Attal¹,⁴

¹Paris Descartes University, Biomaterials laboratory URB2i – EA 4462, Platinum, Paris, France, ²Paris Descartes University, Department of Conservative Dentistry, Paris, France, ³Paris Descartes University, Department of Prosthodontics, Paris, France, ⁴Paris Descartes University, Department of Biomaterials, Paris, France, ⁵Paris Descartes University, Department of Engineering Research, Paris, France

**Objective:** To include CAD/CAM technologies in oral rehabilitation teaching.

Three difficulties arise when bringing and applying the theoretical knowledge in clinical training:

* To offer a standard teaching to all students,

* In 4 dental units located in different hospitals,

* Under a high level supervision.

**Materials and method:** A dedicated room is equipped with three different CAD/CAM systems and a 3D printer, as well as characterization and polishing kits (ceramic, composite and furnace). In clinic, with his teacher, the student indicates the partial restoration and performs preparation and impression (conventional or optical). Design and manufacturing are realized at the faculty under the supervision of a multidisciplinary team, including biomaterials, prosthodontics and conservative dentistry teachers, prosthodontics technicians, engineering specialists and researchers.

**Results:** In this privileged dialogue about a patient, the student discovers the unit scientific interest, as all clinical relevant information about patients, clinical situation and restoration features is recorded for a long-term cohort study. Teachers note a better comprehension of preparation needs and tissue preservation while the student manages the whole process of partial denture restoration. His understanding widens when confronted to clinical situation, cast model and 3D reconstruction.

**Discussion and conclusion:** CAD/CAM is a key teaching in 21st century dental curriculum. These new technologies confront us to a new educational challenge. Because of the limited background available, a multidisciplinary team is necessary to explore the opportunities they open as well
as their limitations. From this point of view, collaboration with researchers is essential.

## DE06

# Comparing the Effectiveness of Dental Health Education Program Using Digital Aids and Conventional Methods

Kundabala Mala

Manipal College of Dental Sciences, Mangalore, Mangalore, India

**Introduction:** Health education is very important tool for health promotion, helps to improve the health of populations, thus promote health capital. Access to appropriate education tools, engaging people in effective health education practice, reaching people of remote and rural areas, time and cost involved in health education and effective and timely support from government are some of the challenges that exist. Advances in technology such as computers and images in a multimedia presentation have made the messages to be delivered more comprehensively to patients to help them understand the available treatment options.

**Objectives:** the present study was undertaken to evaluate and to compare the effectiveness of Dental Health Education program using digital aids with conventional methods in improving oral health knowledge, practices and oral health status of dental patients.

**Methodology:** The study utilized "Activated Health Education Model". A total no. of 150 individuals divided randomly into 2 groups of 75 each for conventional and digital technique respectively. Pre-education questionnaire was collected to evaluate oral health knowledge, awareness and attitude from all the samples. Pre-education plaque index, DMFT and gingival scores were recorded. Education was conducted by digital and conventional methods. 3 months post education mean scores with standard deviation were tabulated for both conventional and digital education techniques. Statistical analysis of Variance was done using one way Anova and post Hoc test.

**Conclusion:** There is no difference between digital aids and conventional educational methods but dental education has a definite role in improving patient knowledge, awareness regarding oral health.

## DE07

# Dental pre-clinical education with haptic-based virtual reality: state of art and challenges

Minh Tran Bui¹,², Céline Gaucher¹,², Jean-Jacques Lasfargues¹,³

¹Conservative dentistry and Endodontics department of Paris Descartes dental school, Montrouge, France, ²Albert Chenevier Hospital, GHHM, AP-HP, Creteil, France, ³Bretonneau hospital, HUPNVS, AP-HP, Paris, France

**Introduction:** Virtual reality simulation (VRS) has already proved its effectiveness in high reliability organisations (aviation, surgery...). It is now reaching the field of dental education, very sensitive to the integration of gestural dexterity with medical skills and knowledge.

**Objectives:** This study aims to explore the main existing simulators available on the market and assess the potential impacts of haptic-based VRS on dental student formation.

**Materials and methods:** A literature review on haptic-based VRS was performed and a comparison of the main commercial systems (VirTeaSy, HRV®; Simodont, Moog® and Voxel-Man Denta, Voxel-Man®) was elaborated after dataset analysis and experimental testing. In addition, an assay with students and teachers was performed on the VirTeaSy simulator at the Paris Descartes dental school.

**Results:** Literature analysis as well as simulator comparison have led to the conclusion that haptic-based VRS would be an interesting complementary system to conventional trainings. Relevance of the simulators is demonstrated in terms of construct and content validities. While satisfactory, face validities and ergonomics have to be improved. Live tests at the Paris Descartes dental school confirm these data and point to the high degree of adaptability of novice face to simulators.

**Conclusion:** Haptic-based VRS systems are promising tools for dentist education. They allow progressive skill acquisition together with self-assessment, and interactive follow up of the learning curve for teachers. For a better integration, simulators contents should be thought in-depth within university communities and further research needs to be conducted.

## DE08

# Qualitative Analysis of Dental Practitioners’ Perceptions of a Part Time Master’s in Restorative Dentistry

Peter Fine, Albert Leung, Chris Louca

UCL Eastamian Dental Institute, London, UK

**Objective:** This study explores the perceptions of General Dental Practitioners (GDPs) following the completion of a five year, part time MSc in Restorative Dental Practice (RDP). It also explores potential new pedagogy for programme development. Qualitative data were collected. The learning experience and perceived impact of new knowledge and skills on general dental practice were explored.

**Method:** Qualitative data from the GDP participants were collected via questionnaires and individual interviews. The questionnaires requested responses to open ended questions on overall perceptions of the programme, perceived impact of the programme on clinical practice and future career aspirations. The interviews (in person or by telephone) were semi structured and complimented the questionnaire.

**Results:** 18 questionnaires were distributed. 94% (n = 17) were returned and 61% (n = 11) of the participants were interviewed. Analysis of the qualitative data revealed: i) achievement of an overall satisfactory learning experience ii) a significant improvement in confidence iii) positive changes to clinical practice iv) work related restrictions in implementing newly acquired knowledge and skills and v) a tendency to use personal development plans for future studies. Criticisms included a lack of feedback from the teachers and inconsistencies with student supervision.

**Conclusion:** Following the MSc, GDP participants perceived the programme had a positive impact on clinical practice and a distinct improvement in their confidence to undertake restorative dental treatment. An increase in treatment uptake by the patients and a perceived improvement in employment opportunities were also noted. In addition teachers on such PG programmes should be adequately trained and appropriately mentored.
# Endodontics & Pulp Biology (EP)

## EP01

### Clinical outcomes of non-surgical root canal treatment of mandibular second molar with C-shaped canals

Hye-Ra Ahn, Young-Mi Moon, Min-Seock Seo

Wonkwang university daejeon dental hospital, Daejeon, Chungcheongnam-do, Republic of Korea

The aims are to evaluate the clinical outcomes of non-surgical root canal treatment of mandibular second molar with the comparison between C-shaped and non-C-shaped canals in terms of periradicular healing and tooth survival, and to investigate their prognostic factors.

Total 109 teeth treated by non-surgical root canal treatment were analyzed retrospectively. The clinical outcomes of non-surgical root canal treatment were determined by clinical and radiographic evaluation. Periradicular healing and tooth survival estimates were compared using Kaplan-Meir analysis. The contributions of a patient's age and gender, number of canal, canal type, tooth location, preoperative diagnosis, and existence of crack were investigated using the multivariate Cox proportional hazard model.

The mean follow-up period was 24.2 months. The overall survival rate was 57.8% and the survival rate of teeth with C-shaped canals was 60.6%. The survival rates were 41.7% for cracked teeth and 51.8% for teeth with apical periodontitis. Amongst the variables tested, existence of crack, and preoperative periradicular status significantly affected the survival rate of a tooth. Other prognostic variables such as age, gender, number of canal, and tooth location did not affect the survival of mandibular second molar with C-shaped canals after non-surgical root canal treatment.

In conclusion, mandibular second molar with C-shaped canals, which has been vaguely considered hard to be treated, did not suggest necessarily the higher failure of root canal treatment than non-C-shaped canals in this study. Preoperative existence of crack and preoperative diagnosis were the most influential factors of treatment failure.

## EP02

### In Vitro Assessment of Force Generated by Different Novel Nickel-Titanium Rotary Systems

Anwer Eshaq, Salman Alsalman, Federico Foschi, Francesco Mannocci

King's College Of London, London, UK

**Aim:** The aim of the present study was to compare *in-vitro* the force necessary to reach the apical portion of the natural root canals in extracted human teeth of the new PTN files with other files including PTU, Revo-S and RaCe123 by a miniature load-testing machine.

**Methodology:** Eighty mesio-buccal canals of extracted human permanent maxillary first and second molars teeth were manually prepared, to the pre-determined working length, up to a size ISO 15 K-flexofile. The teeth were randomly assigned to four groups of 20 samples each (PTN, PTU, RaCe123, and Revo-S). The teeth were mounted on one end of a miniature load-testing machine while the files/handpiece assemblies were mounted on the other. The canal preparation was undertaken at a pre-set velocity towards the apex, while the machine measured the apical force applied on the file. Maximum and average forces were calculated and statistically analysed using Kruskal-Wallis and Mann-Whitney-U test analyses of variance followed by the Bonferroni correction for multiple testing.

**Results:** Statistically significant differences in the forces applied by the different filing systems were noted in the experimental groups, with the Revo-S and PTN generally scoring the lowest average forces (with the concomitant highest peaks) when reaching the apical third and fourth quarters of the canal length, followed by RaCe123 and PTU.

**Conclusion:** The results, within the limitations of this study, indicated that the ProTaper Next and Revo-S systems required less apical force during root canal shaping than ProTaper Universal and RaCe 123.

## EP03

### Bacterial invasion into radicular dentine

Simone Stauffacher¹, Klaus W. Neuhaus¹, Adrian Lussi¹, Sigrun Eick²

¹University of Bern: Department of Preventive, Restorative, and Pediatric Dentistry, Bern, Switzerland, ²University of Bern: Department of Periodontology, Bern, Switzerland

**Introduction:** Penetration of bacteria into radicular dentine, may lead to endodontic failure because these microorganisms are protected against chemo-mechanical treatment. Most endodontic persistent infections are not caused by only a single species.

**Aim:** The aim of this study was to investigate differences in penetration of root dentinal tubules by mono-cultured and by co-cultured bacteria frequently found in infected root canal.

**Materials and Methods:** 51 human roots were inoculated with mono-cultured *Streptococcus gordonii* (Sg), *S. sanguinis* (Ss), and five anaerobes as well as with anaerobes co-cultured with a streptococcal species for 8 weeks. Thereafter samples from the inner, middle and outer part of the root dentine of lengthwise broken teeth (n = 5) were cultivated. In addition, scanning electron microscopy (SEM) photographs were taken.

**Results:** Single grampositive species were able to penetrate onto the middle and outer part of the root dentine. *Fusobacterium nucleatum* (*Fn*) was not found in any of the dentine pieces, *Prevotella intermedia* (*Pi*) and *Porphyromonas gingivalis* in the inner and middle parts.

Except for co-culture with *Pi*, streptococci were always found more often in middle and outer parts in co-cultures when compared with single infection. In co-cultures with streptococci *A. viscosus* was found in 9/10 samples in the outer parts, whereas *Pi* was not detectable in dentine. Co-culture with *Ss* enabled *Fn* to invade dentine; SEM photographs showed a swollen shape of *Fn*.

**Conclusions:** Oral streptococci promote or inhibit invasion of anaerobes in radicular dentine.

## EP04

### Representative Survey on the Reprocessing of Endodontic Instruments in Germany

David Sonntag, Evelyn Martin, W.H.-M. Raab

Department of Operative and Preventive Dentistry, Periodontology and Endodontology, Düsseldorf, Germany
**Aim** The aim of the study was to review the implementation of hygiene guidelines for the reprocessing of endodontic instruments in a representative survey and to determine the time needed for the procedure.

**Methodology** A questionnaire with nine items was sent to 4000 German dentists. In addition to obtaining personal information, the procedure and total time required for the reprocessing of instruments were calculated to determine whether the requirements of the German Federal Ministry of Health were complied with. The data were analyzed statistically using the Chi-square test and Cramer’s V as a measurement of effect size.

**Results** The response rate was 29.4%, 1118 (27.95%) questionnaires could be included in the evaluation. With effect sizes between 0.12 and 0.21, the survey could be classified as statistically representative of German dentists in terms of age and gender. 68.3% of respondents adhered the guidelines either not fully or not at all (P < 0.001). There were no significant differences in adherence to guidelines between younger (<45 years) and older (>44 years) dentists (P = 0.179) or between women and men (P = 0.194). The reported time for cleaning a patient-related instrument set was more than 9 min for 68.1% of respondents, not including the time needed for sterilization; 5% of respondents treated files as single-use instruments.

**Conclusions** The guidelines of the German Federal Ministry of Health for cleaning, disinfecting and sterilizing endodontic instruments are widely disregarded in Germany. The designation and use of endodontic instruments as single-use instruments should be considered.

EP05

Cyclic fatigue resistance of conventional and new generation nickel-titanium rotary instruments. an in vitro comparison.

Celia Ruiz-Sánchez, Vicente Faus-Matoses, Teresa Alegre-Domingo, Vicente J. Faus-Llácer

Valencia University. Master in Restorative Dentistry and Endodontics, Valencia, Valencia, Spain

**Objective:** The purpose of this study was to compare the cyclic fatigue resistance (FC) of 3 nickel-titanium (NiTi) endodontic instrument, ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland), Profile Vortex Blue (PVB; Dentsply Tulsa Dental, Tulsa, OK, USA) and ProTaper Universal (PTU; Dentsply Maillefer, Ballaigues, Switzerland).

**Methods:** Cyclic fatigue test was conducted by operating instruments from ProTaper Next X2, Profile Vortex Blue 25.06 and ProTaper F2. A total of 198 instruments were rotated in 2 simulated stainless steel curved canals with different angles of curvature (45° and 60°) and 5-mm radius of curvature. The number of cycles to fracture (NCF) was calculated. Data were compared by using 2-way analysis of variance (P < 0.05).

**Results:** PVB showed better resistance to cyclic fatigue in both curved canals than PTN and PTU. The lowest resistance to cyclic fatigue canals were obtained by PTU.

**Conclusions:** From the tested rotary files, PVB was the most resistant to fatigue failure; and PTN showed higher number of cycles to failure than PTU.

EP06

C-shaped root canals of mandibular second molars: an in vivo cone-beam computed tomography study

Yemi Kim

Department of Conservative Dentistry, Ewha Womans University, Seoul, Republic of Korea

**Objective:** To investigate the anatomical features of C-shaped root canal system in mandibular second molars in a Korean population by using cone-beam computed tomography (CBCT).

**Methods:** A total of 960 subjects with bilateral mandibular second molars were enrolled. The prevalence of C-shaped root canals and their anatomical features were determined. Root canal configurations at four different levels were categorized based on modified Melton's classification. Differences in the prevalence of C-shaped root canal systems between sex, age, and tooth position (right or left side) were compared using the Chi-squared test.

**Results:** Of the 1,920 mandibular second molars, the prevalence of C-shaped roots was 40.10%. C-shaped roots in combination with additional mesiolingual or distolingual roots were found in 0.73% of molars. Of the C-shaped roots, the most common configuration types were Melton's type I (66.36%) in the coronal region and Melton's type III (55.58%) in the apical region. The prevalence of C-shaped roots was higher in females (46.92%) than in males (32.09%) (P < 0.001) and did not differ with age (P = 0.497) or tooth position (P = 0.514). Most (82.34%) C-shaped canals were symmetrical (P < 0.001).

**Conclusions:** A high prevalence of C-shaped canals were observed in the mandibular second molars of the Korean population. The configuration of C-shaped canals varied along the length of the root.

This research was supported by the National Research Foundation (NRF-2012R1A1A1012913 and NRF-2012M3A9B6055379) of South Korea.

EP07

Sealing ability of 2 root-end filling materials: a comparative in-vitro study

Blanca Faci-Martin¹, Vicente Faus-Matoses², Teresa Alegre-Domingo³, Vicente J. Faus-Llácer⁴

¹Valencia University. Master Student in Restorative Dentistry and Endodontics, Valencia, Valencia, Spain, ²Valencia University. Associate Professor of Master in Restorative Dentistry and Endodonics., Valencia, Valencia, Spain, ³Valencia University. Associate Professor of Master in Restorative Dentistry and Endodonics., Valencia, Valencia, Spain, ⁴Valencia University. Professor and Director of the Master in Restorative Dentistry and Endodonics., Valencia, Valencia, Spain

**Introduction:** Periradicular surgery involves the root-end cavity preparation and its filling. MTA is considered the gold-standard retrograde filling material.

Recently, a bioceramic cement which is called Biodentine (Septodont, Saint Maur des Fossés, France), with similar and improved properties compared to MTA, has been introduced.