bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proffered Papers  10.30–11.15 Monday 15 September 2003 4 An audit of the positive predictive value of high‐grade dyskaryosis for CIN 2 or worse on histology
Authors: Wadehra V. , Johnson S. J. 
Published: September 2003

The positive predictive value (PPV) of high‐grade dyskaryosis for CIN2 or worse on histology is published annually for the laboratories in the UK National Health Service Cervical Screening Programme (NHSCSP). The laboratories collect this data every year for a 3‐month period from April to June as part of the KC61 return. The laboratory PPV is expected to fall between 65% to 85% and provides an inter‐laboratory comparison figure for the specificity of the laboratory reporting. The PPV of individual consultants reporting the smears is monitored internally.The RVI the PPV fell from 84.9% in 2000–2001 to 78.71% in 2001–2002. PPV for individual consultants showed a drop for four of the five consultants, including a fall from 91.6% to 77.94%. The reasons for the fall were investigated by pursuing data rechecking, accuracy of reporting, cyto‐histological correlation, histology and colposcopy factors and follow‐up cytology. The main cause of the fall lay outside the laboratory in the type of biopsy taken at colposcopy.We conclude that the type of biopsy taken at colposcopy influences the PPV calculation. Informal discussions with others suggest comparison between laboratories is not reliable as departments vary in how the KC61 data is collected. As the type of data effects the correlation results, we conclude that caution must be exercised in inter‐laboratory comparisons until more standardization is introduced in histology data collection for PPV for the KC61. It is suggested that other laboratories view their PPV data with our findings in mind.
Simulated variations in atmospheric CO2 over a Wisconsin forest using a coupled ecosystem–atmosphere model
Authors: Scott Denning A. , Nicholls Melville , Prihodko Lara , Baker Ian , Vidale Pier‐Luigi , Davis Kenneth , Bakwin Peter 
Published: August 2003

AbstractEcosystem fluxes of energy, water, and CO2 result in spatial and temporal variations in atmospheric properties. In principle, these variations can be used to quantify the fluxes through inverse modelling of atmospheric transport, and can improve the understanding of processes and falsifiability of models. We investigated the influence of ecosystem fluxes on atmospheric CO2 in the vicinity of the WLEF‐TV tower in Wisconsin using an ecophysiological model (Simple Biosphere, SiB2) coupled to an atmospheric model (Regional Atmospheric Modelling System). Model parameters were specified from satellite imagery and soil texture data. In a companion paper, simulated fluxes in the immediate tower vicinity have been compared to eddy covariance fluxes measured at the tower, with meteorology specified from tower sensors. Results were encouraging with respect to the ability of the model to capture observed diurnal cycles of fluxes. Here, the effects of fluxes in the tower footprint were also investigated by coupling SiB2 to a high‐resolution atmospheric simulation, so that the model physiology could affect the meteorological environment. These experiments were successful in reproducing observed fluxes and concentration gradients during the day and at night, but revealed problems during transitions at sunrise and sunset that appear to be related to the canopy radiation parameterization in SiB2.
Simulated and observed fluxes of sensible and latent heat and CO2 at the WLEF‐TV tower using SiB2.5
Authors: Baker Ian , Denning A. Scott , Hanan Niall , Prihodko Lara , Uliasz Marek , Vidale Pier‐Luigi , Davis Kenneth , Bakwin Peter 
Published: August 2003

AbstractThree years of meteorological data collected at the WLEF‐TV tower were used to drive a revised version of the Simple Biosphere (SiB 2.5) Model. Physiological properties and vegetation phenology were specified from satellite imagery. Simulated fluxes of heat, moisture, and carbon were compared to eddy covariance measurements taken onsite as a means of evaluating model performance on diurnal, synoptic, seasonal, and interannual time scales. The model was very successful in simulating variations of latent heat flux when compared to observations, slightly less so in the simulation of sensible heat flux. The model overestimated peak values of sensible heat flux on both monthly and diurnal scales. There was evidence that the differences between observed and simulated fluxes might be linked to wetlands near the WLEF tower, which were not present in the SiB simulation. The model overestimated the magnitude of the net ecosystem exchange of CO2 in both summer and winter. Mid‐day maximum assimilation was well represented by the model, but late afternoon simulations showed excessive carbon uptake due to misrepresentation of within‐canopy shading in the model. Interannual variability was not well simulated because only a single year of satellite imagery was used to parameterize the model.
Evaluation of root‐end cavity preparation using ultrasonic retrotips
Authors: Ishikawa H. , Sawada N. , Kobayashi C. , Suda H. 
Published: September 2003

AbstractAim  To evaluate and compare the efficiency of root‐end preparations using ultrasonic retrotips coated with diamond and zirconium nitride.Methodology  Eighty‐five extracted single‐rooted teeth were root filled, and then resected 3 mm from their apices. Root‐end cavities were prepared with KiS (zirconium nitride‐coated retrotip), CT‐5 (stainless steel tip) or diamond‐coated (DC) ultrasonic retrotips, and 10 teeth served as controls. Thirty teeth were used for evaluation of the time required to prepare the root‐end cavity, the number of microcracks produced on the resected surface and the number of dentinal tubule openings on the root‐canal wall using scanning electron microscope (SEM) images. A further 55 teeth were used for evaluation of dye penetration following filling of the root‐end cavities with Super EBA. The degree of dye penetration in millimetres was measured under the microscope after 7 days of immersion in India ink. Statistical analyses were performed using the one‐way anova and Scheffe's F‐test as the post hoc test.Results  There was no significant difference in the number of microcracks and dentinal tubule openings present in the root apices prepared by the three retrotips. The time required for root‐end cavity preparation using the DC retrotip was significantly less than that using the other groups (P < 0.01). Positive controls showed dye penetration throughout the length of the root‐end cavity, and negative controls showed no dye penetration. There was no significant difference between the three experimental groups in dye penetration.Conclusions  In this laboratory study, the time required to prepare root‐end cavities using KiS retrotips was the same as that using CT‐5 retrotips, and longer than that using DC retrotips. There was no significant difference in the number of microcracks or dye penetration between the three kinds of retrotips.
Percentage of filled canal area in mandibular molars after conventional root‐canal instrumentation and after a noninstrumentation technique (NIT)
Authors: Ardila C. N. , Wu M‐K. , Wesselink P. R. 
Published: September 2003

AbstractAim  To compare the percentage of filled canal area in mandibular molar roots after using conventional root‐canal hand instrumentation or after a noninstrumentation technique (NIT).Methodology  Forty mandibular molars were used shortly after extraction. The root canals of 20 molars in the manual group were conventionally prepared using hand instruments and then filled with warm vertical compaction of gutta‐percha. The 20 teeth in the second group were cleaned and obturated by NIT. In each case, the entire molar, including the crown and the roots, was embedded in an acrylic resin cylinder before NIT. Horizontal sections were cut at 2, 4, 6 and 8 mm from the apex. Images of the sections were taken using a microscope at ×40 magnification and a digital camera; the images were scanned as Tagged Image File Format (TIFF) images into a PC. The cross‐sectional area of the canal with the filling materials was measured using an image analysis programme. The percentage of filled area was calculated. The difference in the percentage of filled canal area between the two groups was analysed using a Student's t‐test.Results  At all levels, 93–100% of the canal area was filled in both groups. No significant difference was found between the manual technique and the NIT technique at any level (P > 0.05).Conclusions  Within the limitations of this study, following the cleaning and filling of root canals using NIT, the percentage of filled root canal was similar to that using warm vertical compaction of gutta‐percha after conventional root‐canal instrumentation.
Catalase activity in human healthy and inflamed dental pulps
Authors: Esposito P. , Varvara G. , Caputi S. , Perinetti G. 
Published: September 2003

AbstractAim  To examine the catalase activity in clinically healthy and symptomatic human dental pulps to verify if an active defence system against oxidizing agents is present as a response to bacterial invasion.Methodology  Thirty‐three systemically healthy patients, 18 females and 15 males (ages: 11.0–25.9 years; mean 18.8 ± 3.6), were the source of the pulp tissue. The condition of the pulps was assessed using clinical and radiographic evaluations. The specimens were recovered by longitudinally grooving and splitting the teeth (if extracted) or during endodontic treatment, and were matched for age and sex between the healthy and inflamed specimen groups. Catalase activity was determined through spectrophotometric methods.Results  Enzymatic activity was 1126 ± 343 and 3074 ± 698 mU mL−1 × mg of total protein in the healthy and inflamed pulp tissue specimens, respectively. This difference was statistically significant (P < 0.01).Conclusions  These results indicate a role for catalase during dental pulp inflammation in humans, and may represent an inherent biological defence system against reactive oxidants of this tissue.
Evaluation of time required for recontamination of coronally sealed canals medicated with calcium hydroxide and chlorhexidine
Authors: Gomes B. P. F. A. , Sato E. , Ferraz C. C. R. , Teixeira F. B. , Zaia A. A. , Souza‐Filho F. J. 
Published: September 2003

AbstractAim  To determine in vitro the time required for recontamination of coronally sealed canals medicated with either calcium hydroxide (Ca(OH)2), 2% chlorhexidine gel (CG) or with a combination of both.Methodology  Eighty intact, caries‐free, premolar teeth with straight roots and mature apices were selected for the study. After biomechanical preparation of 75 teeth, they were randomly divided into nine groups according to the intracanal medicament and the coronal seal with ‘Intermediate Restorative Material’ (IRM) as follows: (i) 10 teeth medicated with CG, coronally unsealed; (ii) 10 teeth medicated with Ca(OH)2, coronally unsealed; (iii) 10 teeth medicated with Ca(OH)2 + CG, coronally unsealed; (iv) 10 teeth medicated with CG + coronal seal; (v) 10 teeth medicated with Ca(OH)2 + coronal seal; (vi) 10 teeth medicated with CG + Ca(OH)2 + coronal seal; (vii) 10 teeth without intracanal medicament and coronally sealed; (viii) 5 teeth without intracanal medicament and coronally unsealed, used as the positive control group (PC); (ix) 5 teeth with intact crowns used as the negative control group (NC). Glass flasks were filled with Brain Heart Infusion broth (BHI), so that only the root apex was in contact with the broth, while the crown was immersed in human saliva + BHI (3 : 1). The flasks were then incubated at 37 °C in an atmosphere of 10% CO2, and microbial growth was checked daily.Results  All specimens of the PC showed contamination within 1 day of incubation, while the NC showed no evidence of broth turbidity. Recontamination was detected after an average time of 3.7 days in the unsealed canals medicated with CG, 1.8 days in the group medicated with Ca(OH)2 and 2.6 days in the group medicated with Ca(OH)2 + CG. When the crowns were sealed with IRM, recontamination was detected within 13.5 days in the canals medicated with CG, after 17.2 days in the group medicated with Ca(OH)2 and after 11.9 days in the group medicated with CG + Ca(OH)2. The group with no medication, but sealed with IRM, showed recontamination after 8.7 days. There were statistically significant differences between the teeth with or without coronal seal (P < 0.05).Conclusion  The coronal seal delayed but did not prevent leakage of microorganisms. There was no difference between the various medicaments.
A systematic review of in vivo retrograde obturation materials
Authors: Niederman R. , Theodosopoulou J. N. 
Published: September 2003

AbstractPurpose  The aim of this study was to answer the question: For patients requiring apicoectomy (apicectomy/root‐end resection) and retrograde (root‐end) obturation (filling), which retrograde obturation (root‐end filling) material(s) is/are the most effective, as determined by reduction in periapical radiolucency and elimination of signs and symptoms?Materials and methods  A MEDLINE and a Cochrane search (two specified searches) were conducted to identify randomised (RCT) and nonrandomised controlled clinical trials (CCT), cohort studies (CS) and case‐control studies (CCS), published between 1966 and 2002, October week 4, conducted on humans, and published in English, German and French language, relating to retrograde obturation materials following apicoectomy.Results  The MEDLINE and the Cochrane search identified 324 and 21 published articles, respectively. The Cochrane search identified three additional articles to the MEDLINE‐search articles. Fourteen studies met the inclusion criteria: two were RCTs, six were CCTs, none was a CS and six were retrospective CCSs. Nine of the 14 studies compared a new retrograde (root‐end)‐filling material to amalgam, 4 of the 14 studies compared orthograde root canal fillings to retrograde (root‐end) amalgam and the fourteenth study compared variations of a resin composite (Retroplast) when used in combination with the bonding agent Gluma (Bayer AG, Gluma 1 and 2). The two RCTs indicated that glass ionomer cement appeared to be equivalent to amalgam. The six CCTs indicated that orthograde filling with gutta‐percha and sealer was more effective than amalgam retrograde (root‐end)‐filling (one trial). Similarly, retrograde (root‐end)‐filling with (i) composite and Gluma (Bayer AG, Leverkusen, Germany) as bonding agent (one trial), (ii) reinforced zinc oxide eugenol cement (EBA cement) (Stailine, Staident, Middlesex, England; one trial) and (iii) gold leaf (one trial) appeared to be better than amalgam retrograde (root‐end)‐filling. Finally, gutta‐percha retrograde (root‐end)‐filling appears to be less effective than amalgam (one trial) and Retroplast with ytterbium trifluoride is better than Retroplast with silver, when they are both used with Gluma as bonding agent (one trial).Conclusions  For the highest level of evidence (RCT) retrograde (root‐end)‐filling with glass ionomer cement is almost as effective as amalgam. However, there was a significant caveat as there were only two RCTs. At the next highest level of evidence (CCT), and given the additional caveat that there was only one controlled trial for each material, retrograde (root‐end) EBA cement, composite with Gluma and gold leaf, as well as orthograde gutta‐percha, may be more effective than retrograde (root‐end) amalgam filling. In conclusion, these results suggest that additional validating CCTs and RCTs are needed.
Effect of apical root‐end filling materials on gingival fibroblasts
Authors: Pistorius A. , Willershausen B. , Marroquin B. Briseño 
Published: September 2003

AbstractAim  To determine the influence of root‐end filling materials on specific cellular responses of gingival fibroblasts (GF).Methodology  The reactions of cells in contact with mineral trioxide aggregate (MTA), amalgam and a chemically inert titanium alloy were determined based on the assessment of prostaglandin (PGE2) release with and without arachidonic acid stimulation, protein and lactate synthesis, and cell proliferation. Cells cultured without test materials served as controls (100%).Results  The fibroblasts showed a highly significant decrease in protein synthesis when in contact with amalgam (61.8 ± 13.6%); MTA (91.2 ± 5.9%) and titanium (92.4 ± 4.7%) had little effect on this parameter. The rate of cell proliferation in contact with MTA (98.0 ± 1.6%) and titanium (97.9 ± 7.4%) was only slightly influenced and showed similar values to that of the controls after 96 h of incubation. On the contrary, a significant and continuous reduction in the rate of cell proliferation was observed for cells in contact with amalgam (61.0 ± 2.5%) after 96 h. No significant increases in lactate synthesis values were registered for any of the materials (MTA 101.8 ± 1.7%, titanium 94.8 ± 8.6% and amalgam 105.8 ± 10.3%). There was a significant decrease in PGE2 synthesis potential when cells were in contact with amalgam (85.2 ± 3.5%). In comparison to the controls, titanium and MTA resulted in an elevated level of cellular PGE2 synthesis (titanium: 131.6 ± 19.1%; MTA: 147.3 ± 18.9%). The cell cultures stimulated with arachidonic acid (10−5 m) showed no significant differences with any material (MTA: 88.8 ± 17.6%, titanium: 97.6 ± 14.4%, amalgam: 85.5 ± 16.8%).Conclusions  MTA demonstrated cellular responses similar to those of titanium. Amalgam showed an irritation rate higher than that of MTA and titanium.
The antimicrobial efficacy of ‘MGP’ gutta‐percha in vitro
Authors: Shur A. L. , Sedgley C. M. , Fenno J. C. 
Published: September 2003

AbstractAim  To determine whether ‘MGP’ gutta‐percha (Westport, CT, USA), a commercially available gutta‐percha containing iodoform, inhibits the growth of potential endodontic pathogens.Methodology  Inocula of Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Streptococcus sanguis, Fusobacterium nucleatum and Actinomyces odontolyticus were spread onto the surface of agar plates. ‘MGP’ gutta‐percha cones presoaked in sterile water were transferred to the inoculated agar and incubated at 37 °C aerobically or anaerobically as required for optimal growth. Identical studies were performed using iodoform‐free gutta‐percha and sterile paper disks saturated with 10% povidone–iodine. Following incubation, zones of inhibition around the ‘MGP’ gutta‐percha, iodoform‐free gutta‐percha and disks were evaluated.Results  Povidone–iodine inhibited all the strains. Iodoform‐free gutta‐percha inhibited S. sanguis and A. odontolyticus. ‘MGP’ gutta‐percha inhibited S. aureus, S. sanguis, A. odontolyticus and F. nucleatum. Neither iodoform‐free gutta‐percha nor ‘MGP’ gutta‐percha inhibited growth of E. faecalis, E. coli or P. aeruginosa.Conclusions  Compared to iodoform‐free gutta‐percha, iodoform‐containing ‘MGP’ gutta‐percha had an inhibitory effect in vitro on S. aureus and F. nucleatum, but not on E. faecalis, E. coli or P. aeruginosa.
Acidity of conventional luting cements and their diffusion through bovine dentine
Authors: Hiraishi N. , Kitasako Y. , Nikaido T. , Foxton R. M. , Tagami J. , Nomura S. 
Published: September 2003

AbstractAim  To examine the changes in pH of luting cements and acid diffusion of luting cements through bovine dentine using a pH‐imaging microscope (SCHEM‐100; Horiba Ltd, Kyoto, Japan).Methodology  The pH of the surface of three conventional luting cements, glass‐ionomer, zinc phosphate and zinc polycarboxylate was measured with SCHEM‐100 for 1 month. The acid diffusion from the three luting cements through bovine dentine was investigated by measuring pH changes during the application of each luting cement on the bovine dentine surface. Coronal bovine dentine disks were prepared to thicknesses of 0.50 and 0.25 mm. Each luting cement was placed on the labial dentine surface, and the pH change of the pulpal surface was observed every 3 min for 30 min with SCHEM‐100.Results  Glass‐ionomer showed the lowest pH values for longer times. Neutralization proceeded furthest in zinc polycarboxylate. The 0.5‐mm‐thick dentine disks showed no pH change on the pulpal side with all the three cements. The 0.25‐mm‐thick disks revealed evidence of acid diffusion on the pulpal side of the cemented dentine and significantly lower pH when cemented with glass‐ionomer and zinc phosphate than with zinc polycarboxylates.Conclusions  This study demonstrated that glass‐ionomer exhibited a lower setting pH than zinc phosphate and zinc polycarboxylate, and acid diffusions from glass‐ionomer and zinc phosphate cements were observed when placed on 0.25‐mm‐thick dentine disks.
A comparative study of selected physical properties of five root‐canal sealers
Authors: McMichen F. R. S. , Pearson G. , Rahbaran S. , Gulabivala K. 
Published: September 2003

AbstractAim  To investigate selected physical properties of five root‐canal sealers.Methodology  The solubility, film thickness, flow, working and setting times of Roth 801®, Tubli‐Seal EWT®, AH Plus®, Apexit® and Endion® were evaluated. Solubility was measured by weight change of standard specimens in water over a 3‐month period. Film thickness was measured as the distance between weighted glass slides containing a standard quantity of sealer. Flow was assessed by rate of sealer extrusion through a standard bore diameter, after unit time. Working time was taken as the point at which flow rate was reduced by 10%. The indentation test using a modified Gilmore needle was employed to investigate the setting times.Results  AH Plus® was the least soluble, whilst Apexit® was the most unstable in water. The solubility values in increasing order were: AH Plus® < Tubli‐Seal EWT® < Endion® < Apexit®. Also, AH Plus® had the highest film thickness. All sealers showed comparable flow rates. The working time varied from 50 min for Endion® to over 2 h for AH Plus® and Tubli‐Seal EWT®. The range of setting times recorded was from 70 min for Tubli‐Seal EWT® to 8 days for Roth 801®.Conclusions

AH Plus® showed the greatest stability in solution and Tubli‐Seal EWT® performed well, but Apexit® and Endion® had higher solubility values.
The film thickness values in increasing order were: Tubli‐Seal EWT® < Apexit® < Endion® = Roth 801® < AH Plus®.
The flow rates for all sealers were similar.
The working times for all sealers were greater than 50 min.
Roth 801® did not set when incubated in volumes sufficient to fill the test matrices.
A comparison of the minimum canal wall thickness remaining following preparation using two nickel–titanium rotary systems
Authors: Garala M. , Kuttler S. , Hardigan P. , Steiner‐Carmi R. , Dorn S. 
Published: September 2003

AbstractAim  To examine in vitro whether Profile or Hero 642 nickel–titanium rotary instrument systems substantially reduce the minimum canal wall thickness present following root‐canal preparation.Methodology  The canal anatomy of 26 mesial roots from mandibular molars with separate buccal and lingual canals was evaluated before and after instrumentation using the Endodontic Cube. Following access, working lengths were determined and then samples invested within the cube using acrylic resin. Canal cross‐sections were subsequently prepared. Samples were then instrumented within the cube and pre‐ and post‐instrumentation images of the sections were compared to determine the minimum canal wall thickness remaining after preparation.Results  Buccal and lingual canals within the sections from each level (coronal to apical) showed a reduction in minimum canal wall thickness after instrumentation. No statistically significant differences in canal wall thickness were found between the two systems at any level of the root.Conclusions  Instrumentation with either of the two systems under investigation did not compromise canal wall thickness. Pre‐operative canal wall thickness was found to be the most significant factor determining the minimum canal wall thickness after preparation.