bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of inorganic fillers in visible‐light‐cured dental composite resins
Authors: KHAN A.M. , SUZUKI H. , NOMURA Y. , TAIRA M. , WAKASA K. , SHINTANI H. , YAMAKI M. 
Published: June 2007

Summary Inorganic fillers in seven visible‐light (VL)‐cured dental composite resins were examined for their size, composition, phase and content, employing the following analytical instruments. SEM observations indicated that five samples could be classified into the hybrid type while the remaining two belonged to micro‐filled and sub‐micron types. EDX analyses revealed that five samples contained BaO while others lacked BaO. XRD analyses showed that three were in vitreous phase, two were in the crystalline phase and two were mixtures of both. DTG thermal analyses indicated that the hybrid type composites had the higher inorganic filler content (wt%) than the composites of two other types.In conclusion, wide varieties exist in the inorganic fillers in VL‐cured dental composite resins currently utilized.
In‐vitro and in‐vivo wear profile of composite resins
Authors: SATOU N. , KHAN A.M. , SATOU K. , SATOU J. , SHINTANI H. , WAKASA K. , YAMAKI M. 
Published: June 2007

SummaryThe aim of this study was to evaluate in‐vitro wear by two types of slurry of 10 commercial composite resin materials (seven hybrid and three microfilled composites). There was great variation in the in‐vitro wear pattern by two types of slurry. The wear rate of microfilled composites was greater than that of hybrid composites, and a negative correlation was observed between wear rate and Knoop hardness values among all materials when hydroxyapatite slurry was used. In contrast, the wear rate of hybrid composites was greater than that of microfilled composites when abraded by green carborundum slurry. These abraded surfaces were compared with SEM micrographs of in‐vivo composites surface after 4 years of service. The profile of in‐vivo wear surfaces was found to be similar to that of in‐vitro wear surfaces abraded with hydroxyapatite slurry.
Idiopathic cervical lesions: in vivo investigation by oral microendoscopy and scanning electron microscopy. A pilot study
Authors: BEVENIUS J. , ĽESTRANGE P. , KARLSSON S. , CARLSSON G.E. 
Published: June 2007

SummaryThe development and progression of cervical lesions have not been thoroughly documented. Clinically, two morphologically distinct forms, saucer‐or wedge‐shaped, have been described. In this study, the micromorphology of manifest cervical lesions was documented in six subjects, by SEM replication and microendoscopy. Optoelectronic recordings were made of extreme mandibular lateral excursions. Salivary parameters were evaluated and a detailed case history, including oral hygiene and dietary habits, was taken.Lesions of varying severity could be observed in the same subject. Longitudinal fractures of the enamel were common. The dietary analyses were uneventful and salivary values were normal. No correlation was found between brushing habits and the location and severity of the lesions. The optoelectronic recordings, however, indicated a possible correlation between irregular lateral excursion and the severity and location of the lesions, with a tendency for fewer and less severe lesions on the preferred chewing side. The results have indicated some areas of interest for future studies applying non‐invasive observation methods.
Posterior palatal seal adaptation: influence of processing technique, palate shape and immersion
Authors: SYKORA O. , SUTOW E. J. 
Published: June 2007

SummaryAccuracy of fit of denture bases is critical to adequate retention. This study compared the dimensional change of a newer continuous‐injection technique with a standard trial‐pack technique as determined by measuring the posterior palatal border opening. The influence of palate shape and immersion were also assessed.Stone casts were made from master moulds with either a high or flat palate. Denture base adaptation was measured at 5 mm intervals across the entire posterior palatal border. Measurements were made after deflasking, trimming and polishing, and after immersion in room temperature water for l h, 1 day and 1 week. Statistical analysis (P < 0.05) showed that where differences occurred between the two techniques, openings were always smaller for the continuous‐injection technique. It was also shown that dimensional changes were always larger for the flat palate compared with the high palate. Dimensional change using the continuous‐injection technique was reduced by immersion in water, while no influence was observed for the trial‐pack technique. It was concluded that the continuous‐injection technique showed smaller dimensional changes compared with the standard trial‐pack technique, and that these changes were influenced by palate shape and immersion in water.
A comparison of three finite element models of an edentulous mandible provided with implants
Authors: MEIJER H.J.A. , STARMANS F.J.M. , BOSMAN F. , STEEN W.H.A. 
Published: June 2007

The stress distribution in an edentulous mandible provided with two implants in the interforaminal region was calculated by means of three different finite element models. The implants were connected with a bar or remained solitary. The first model was a three‐dimensional representation of the entire mandible, the second model of the interforaminal region of this same mandible, whilst the third model was a two‐dimensional representation of the interforaminal region. The differences in stress distribution around the connected implants and the solitary implants between these three models were analysed.It can be concluded that for a parameter study the stress distribution around the dental implants following from a three‐dimensional finite element model of only the interforaminal region of an edentulous mandible can be used. For such studies therefore, benefit can be gained from the advantages of reduced modelling and calculation time.
Longitudinal study on torque around the sagittal axis in lower distal‐extension removable partial dentures
Authors: OGATA K. 
Published: June 2007

The purpose of this study was to examine the longitudinal changes of torque around the sagittal axis in lower distal‐extension removable partial dentures. The torque transmitted from the denture base to retainers was measured on several separate occasions from the insertion of new dentures to about 2 months after it. The maximal mean value of torque (Max.MT) was calculated from the magnitude of all chewing strokes of the minimum of the interocclusal distance. The integration values of torque (I) and time (T) from initiation of chewing to swallowing were obtained and then the average value of torque (Ave.T) was calculated (Ave.T= I/T).Subjects could be divided into two groups. Max.MT and Ave.T were almost constant in one group while they were remarkably decreased in another. After 1 month of insertion of new dentures the value of both groups was within the range of less than 3 × 10‐3 kgm (1 kgm = 9.8 Nm) of Max.MT and less than 1 × 10‐3 kgm ss‐1 of Ave.T.
The use of intermediary resins when bonding glass polyalkenoate (ionomer) cement to composite resin
Authors: WOOLFORD M.J. , GRIEVE A.R. 
Published: June 2007

This study was designed to examine the effects of three different types of glass polyalkenoate lining cement combined with three different types of bonding resin and varying surface treatments on the seal between the lining cement and the composite resin as used in the so called ‘laminate’ technique. The seal was assessed using a radioisotope and autoradiographic technique.Results showed that all the cements behaved in a manner specific to them. The seal of all systems examined could be improved, or at least, not compromised, by modification of the surface of the cement prior to attachment of the resin. Only one type of intermediate resin gave a reliable seal when applied to an unmodified surface of any of the cements under investigation.It is concluded that all the glass polyalkenoate cements tested behave differently when used beneath composite resin. Recommendations about the laminate restoration technique must be related to the specific combinations of materials used.
The release of chlorhexidine from modified dental acrylic resin
Authors: WILSON S.J. , WILSON H.J. 
Published: June 2007

A method for the incorporation of chlorhexidine into acrylic resin using monomer together with the pattern of release of chlorhexidine from treated resin into water at 37°C is described. Release from polished and unpolished resin, and from acrylic prepared by short‐curing and dry‐curing processes are investigated.The pattern of release in all cases was of an exponential nature, showing a rapid release within the first 10 days becoming almost constant at a level of 0.4‐1.5 μg cm‐2 at about 20 days. Release was still evident at the end of the test period in all cases. Release of chlorhexidine into water from the short‐cure specimens was accompanied by release of monomer, evident from the odour of the test solutions, indicating that polymerization was not complete.
Acoustic myography in the assessment of human masseter muscle
Authors: L'ESTRANGE P.R. , ROWELL J. , STOKES M.J. 
Published: June 2007

The feasibility of examining electro‐mechanical activity of the human masseter muscles using non‐invasive recording techniques was examined in six healthy dentate adults (aged 34‐57 years). Electrical activity of the muscle was examined by surface electro‐myography (EMG) and the mechanical activity, in the form of muscle sounds, was examined by acoustic myography (AMG).Bilateral recordings of EMG and AMG were made simultaneously using composite probes which were placed on the skin over the masseter muscles. A standardized pressure was applied to the probes via adjustable rods attached to a safety helmet. Pressures were monitored by strain gauges placed between the ends of the rods and the probes. With the subject seated, recordings of AMG and EMG were obtained during maximal jaw clenching for 4s and the raw signals were stored on a computer. Of three maximal contractions performed, the last two were used in the analysis. The raw amplified signals underwent frequency analysis by fast Fourier Transform. Total activity was also assessed after amplification, full‐wave rectification and integration, and repeatability of the results was assessed.The AMG frequency range was 6‐15 Hz and was similar to values for other human skeletal muscles. The integrated values for EMG and AMG were repeatable on both sides of the face (IEMG, right r = 0.99, left r = 0.99; IAMG right r = 0.70, left r = 0.71). Simultaneous recordings of AMG and EMG from the masseter muscles may be useful for assessing electro‐mechanical muscle function but further validation studies are required before the technique can be used clinically.
Photoelastic evaluation of the standard bionator appliance
Authors: STEFANAC J. , CHACONAS S.J. , CAPUTO A.A. , GRIFFITH J. 
Published: June 2007

A study was undertaken to demonstrate the forces in the craniofacial complex generated by the activation of the standard bionator appliance. A three‐dimensional skull replica of an orthodontic patient with a Class II Division 1 malocclusion in the mixed dentition was fabricated using a urethane based photoelastic material to simulate bone. Four muscles of mastication were simulated on the photoelastic model. Various anatomical areas of the skull were viewed in a circular polariscope and recorded photographically before and after inserting the bionator.The downward and forward repositioning of the lower jaw by the bionator appliance caused various stresses on the craniofacial complex. The photoelastic stresses visualized in this investigation would most likely cause: an increase in the gonial angle; downward repositioning of the midface; and a posterior displacement and expansion of the maxilla.
The carer's perspective: results of a survey of attitudes to dental care in 250 residential homes in Manchester
Authors: HOAD‐REDDICK G. , HEATH J.R. 
Published: June 2007

SummaryA postal survey of 250 residential homes in the Manchester area was undertaken in late spring 1991. The 152 questionnaires returned gave information about 3757 residents. In spite of an apparently adequate understanding of the importance of dental care, carers did not appear to provide as effective a service as they thought necessary. Ninety‐one percent of carers realised dentures do not last indefinitely and 77.4% thought dentures should be checked every 2 years. Yet, in over 50% of homes, there was no provision for regular dental checks and in only 42.8% were residents seen every 2 years. It was pleasing to note that 70.7% of respondents welcomed the suggestion of a half‐day educational workshop. Suggestions are made for assisting homes with areas of particular concern. The importance of good rapport with local dental surgeons is stressed.
Temporary prosthetic base materials: reproduction of surface detail
Authors: HEATH J.R. , BORU T.K. , GRANT A.A. 
Published: June 2007

SummaryThe baseplate material that best reproduced the most grooves in a gypsum cast was filled cold cure acrylic resin, followed in turn by modelling wax, grey shellac and finally the pink shellac material. These latter three thermoplastic materials performed best when softened in a water bath and subsequently adapted to a prewarmed cast.
Effect of loading and syringing on void formation in automixed addition silicone elastomers
Authors: CHONG Y.H. , SOH G. , LIM K.C. 
Published: June 2007

SummaryThe effect of loading and syringing on void formation in five automixed addition silicones was evaluated by determining the voids created in the first and second halves of material loaded and dispensed from a metal syringe. Impressions were made of a model with six stainless‐steel cylinders. The voids were counted at a predetermined site on 3 separate days using a binocular microscope at X 7 magnification. Automixed addition silicones did not confirm the ‘last out‐fewer bubbles’ phenomenon and specific loading and syringing technique did not appear to have a consistent effect on void formation in automixed elastomers.
A technique for treatment of extensive periodontal defects: a case study
Authors: GALGUT P.N. 
Published: June 2007

SummaryThis case study describes the use of oxidized cellulose mesh to improve healing of periodontal defects of poor regenerative capacity. Circumferential defects with horizontal bone loss were treated by surgical exposure of the root surface followed by scaling and root planing. Prior to flap replacement, oxidized cellulose mesh was positioned in incremental layers over the defects so as to replace the lost alveolar bone. It was to act also as a barrier to the ingress of epithlial cells and gingival fibroblasts into the healing wound using the principles vof guided tissue regeneration. Healing was good, with minimal post‐operative recession. Whether regeneration of alveolar bone and periodontal ligament occurred as a result of using this technique could not be determined in this clinical case study.
Masticatory electromyographic activity in healthy young adults and myogenous craniomandibular disorder patients
Authors: VISSER A. , McCARROLL R.S. , OOSTING J. , NAEIJE M. 
Published: June 2007

SummaryThe electromyographic (EMG) activity of the masseter and the anterior temporalis muscles were compared between 60 healthy controls and 61 myogenous craniomandibular disorder (CMD) patients. Subjects were asked to clench at 10% and at 50% of their maximum voluntary clenching level. The effects of CMD, age and gender were statistically analysed with the use of the analysis of covariance. The correlations between EMG asymmetries and the lateral slide from the retruded contact position to the intercuspal position and the asymmetry in the number of post‐canine tooth contacts between the left and the right side were investigated.The CMD patients showed lower masseter EMG activities than the controls, whereas the anterior temporalis EMG activity was not different between the two groups. The activity index, relating the anterior temporalis EMG activity to the activity of the masseter muscles, confirmed the presence of a relatively high temporalis activity in the CMD group. No significant differences were found in the EMG asymmetries between the controls and the CMD patients. Males showed higher masticatory EMG activities than females. These gender effects were significant for the anterior temporalis at the 10% and 50% level and for the masseter muscle at the 10% level. The anterior temporalis EMG activity declined with age. No age related effects were observed in the masseter EMG. The lateral slide was larger and more prevalent in the CMD group. A significant correlation between the lateral slide and the anterior temporalis EMG was found for the CMD group at the 10% level. No correlation was found between the EMG asymmetry and the asymmetries in post‐canine tooth contacts.In conclusion: significant CMD, age and gender effects were observed in the masticatory EMG activities of a group of myogenous CMD patients and a control group.
Symptomatology of patients with oligodontia
Authors: DER WEIDE Y. SCHALK‐VAN , BEEMER F.A. , FABER J.A.J. , BOSMAN F. 
Published: June 2007

SummaryThe aims of the present study were: (i) to identify the association of patterns of congenitally missing teeth with combinations of ectodermal symptoms occurring in patients with oligodontia; and (ii) to propose a diagnostic scheme for the general practitioner.For this study 167 patients with oligodontia, both isolated and as part of a syndrome, and 135 healthy controls were interviewed and documented. Chi‐square tests, logistic regression and correspondence analysis were used to evaluate and test differences between the groups and associations between the congenitally missing teeth and ectodermal symptoms.No significant differences were found between the control group and the patients with isolated oligodontia with exception of the skin. It could be concluded from the present study that there were no clear associations between congenitally missing teeth, either individually or patterns, and the ectodermal symptoms or combinations of ectodermal symptoms.However, it could be concluded that if the most stable teeth are missing, or if the number of missing teeth is large the patient should be examined carefully for symptoms of ectodermal dysplasia.Using logistic regression a patient could be classified as having isolated oligodontia or oligodontia as part of a syndrome with a specificity and sensitivity of 88.2%.
Incidence of temporomandibular joint disorders in patients seen at a hospital emergency room
Authors: LUZ J.G.C. , OLIVEIRA N.G. 
Published: June 2007

SummaryA retrospective survey of a hospital emergency room population seen at an oral and maxillofacial surgery clinic during a 6‐month period found 62 patients (2.7% of the total population) with temporomandibular joint disorders. The diagnoses were myofascial pain‐dysfunction/temporomandibular joint dysfunction (MPD/TMJ) syndrome (70.9% of the cases) and dislocation (luxation) (22.5% of the cases).The chief complaint was well defined in relation to the diagnoses: facial pain in the MPD/TMJ syndrome cases, and displacement of the mandible in the dislocation cases.
Bone augmentation using a synthetic bone graft in dogs
Authors: HÜRZELER M.B. , EINSELE F. , LEUPOLZ M. , SCHMITZ H.J. , STRUB J.R. 
Published: June 2007

SummaryThe aim of this investigation was to evaluate clinically and histologically the use of a synthetic bone graft (Ionogran®) alone and in combination with guided bone regeneration (GBR) for alveolar ridge augmentation. Five beagle dogs were used in this study. Prior to the augmentation procedure the maxillary and mandibular second, third and fourth premolars were extracted. Three months after the extractions, impressions from the area of the ridges were taken. Particles of Ionogran® were then placed under mucoperiosteal flaps in each quadrant. On the experimental sites, an expanded polytetrafluoroethylene barrier was placed between the flap and the particles. Impressions were retaken at 1 and 3 months after surgery. Three months after surgery, the animals were sacrificed and specimens were prepared for histological evaluation. Computer‐assisted volumetric analyses from the casts revealed an increase in ridge volume from baseline in both groups at 1 and 3 months. There was no difference in the height of the augmentation between the test and control sites. The histological results of this study indicate that this new synthetic bone graft appears to be a safe biocompatible grafting material. There were no apparent histological differences between the graft alone and graft/GBR sites. In both groups, however, graft particles were surrounded by dense fibrous connective tissue and bone formation was limited to the graft bone interface.
The effect of smear layer removal on marginal contraction gaps
Authors: SOH G. , SIDHU S.K. 
Published: June 2007

SummaryThe presence of the smear layer prevents direct contact between dentine and a dentine adhesive. The use of agents to remove the smear layer theoretically should improve the bonding of composite resins to dentine. This study examined the effect of smear layer removal on the effectiveness of a dentine bonding agent in reducing marginal contraction gaps. The agent used for smear layer removal in this study was ethylenediamine tetra‐acetic acid (EDTA). Eighty cavities measuring 2mm in diameter and 1.5 mm in depth were prepared in dentine and randomly assigned to two equal groups. The control group was restored with Prisma Universal Bond 2 Adhesive and Prisma Fil Resin. The experimental group was similarly restored after pretreatment of dentine with 0.5% EDTA for 60s. All specimens were thermocycled and the marginal contraction gaps were assessed using a Nikon Measurescope. The mean contraction gap was expressed as a percentage of the cavity diameter. Results showed that the experimental group registered smaller contraction gaps (mean: 0.021%) than the control group (mean: 0.027%). No penetration of material into dentine was observed. Pretreatment with EDTA did not significantly improve the effectiveness of the dentine bonding agent used in terms of reduction of marginal contraction gaps.