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Notes: Purpose: Marginal integrity is a very important element in evaluating a restoration; however, there is no agreement in definition of a clinically acceptable margin. The purpose of this investigation was to examine margin acceptability using an explorer versus the actual marginal gap widths at four locations on uncemented crowns on three extracted teeth using both predoctoral students and prosthodontists as evaluators. Materials and Methods: The crown margin evaluation used 16 surfaces of four crowns fitting to three extracted caries-free teeth fitted into a dentiform. The teeth (nos. 14, 20, and 29) were prepared for a full cast (gold) crown using a chamfer finish line configuration, with some margins supragingival and others subgingival. After final impressions and working casts were made, die spacer was applied to the marginal area of the die before waxing to vary the marginal opening. The dentiform was placed in a mannequin in a supine position. Predoctoral students (N = 10) and prosthodontists (N = 9) evaluated each axial surface of each crown in the zone along the margin with an explorer and rated each surface as either “clinically acceptable” or “unacceptable.” After casting, the axial marginal openings were measured with Image Pro Software using a digital microscopic image of the surface. Each participant repeated the margin evaluations 6 months later. Results: Upon casting, marginal gaps ranged from 40 μm to 615 μm. The proportions of prosthodontists and of predoctoral students rating a given surface as “clinically unacceptable” were highly correlated (Spearman rank correlation = 0.81, p= 0.0001). The prosthodontists did not provide more or fewer ratings of clinical acceptability than the students, although kappa results indicated that the prosthodontists might be more consistent among themselves than the student raters. Upon re-evaluation, both groups rated between one and six of the surfaces differently than they had previously: the median number of inconsistencies was 1 for prosthodontists and 3 for predoctoral students. The prosthodontists tended to have fewer inconsistencies than the predoctoral students (0.05 〈 p 〈 0.10 Wilcoxon rank sum test), but this was not statistically significant. Conclusion: The data provided evidence that those surfaces associated with greater margin gaps tended to have a greater proportion of ratings of “clinically unacceptable.” The proportion of prosthodontists and predoctoral students rating a margin “clinically unacceptable” were highly correlated. Prosthodontists tended to have fewer inconsistencies than predoctoral students, but that difference was not statistically significant.

Notes: Purpose:   This study evaluated the surface roughness of polished provisional materials at baseline and after storage in artificial saliva and artificial saliva–coffee solutions. Materials and Methods: Ten specimens (25 mm × 25 mm × 2 mm) of 12 commercially available provisional crown materials (5 methacrylate and 7 bis-acryl resins) were fabricated and polished. Baseline surface roughness measurements (Ra) were made using a surface roughness tester. Specimens were divided into 2 groups and stored in artificial saliva or artificial saliva–coffee solution at 37°C for 2 weeks. Baseline surface roughness data were analyzed using the analysis of variance; multiple comparisons adjustment was made using the Tukey method. Multiple linear regression methods were used to analyze change in roughness relative to baseline and to assess the impact of storage medium, material, and baseline roughness on this change, including potential interactions among these 3 factors; descriptors of poststorage surface roughness were obtained. Results: Alike demonstrated the greatest surface roughness, both at baseline and after storage (p 〈 0.05 after adjustment for all Pairwise comparison by Tukey method). Temphase, Temporary Bridge Resin, Instatemp, Unifast, Jet, and Zeta had the lowest baseline surface roughness measurements. The lowest poststorage roughness scores were associated with Protemp Garant, Jet, and Integrity. Five materials (Protemp Garant, Instatemp, Unifast, Jet, and Zeta), formed the group having the lowest rough poststorage outcomes. The data provided strong evidence of a material effect (p 〈 0.0001) at baseline. Evaluation of change in Ra following storage indicated that surface roughness increased for the majority of materials after storage in a moist environment, and that provisional crown materials that exhibit less initial surface roughness tend to undergo greater surface roughness change in a moist environment. Strong indications were found that the effect of the type of storage solution used differed among the materials. Conclusions:   There were significant differences in surface roughness of provisional crown materials when polished under the same conditions. Methacrylate resins in general exhibited smoother surfaces after initial polishing. Surface roughness increased for nearly all materials after storage in either moist environment.

Notes: Purpose: This study compared the linear dimensional changes of 3 injection-molded denture base materials to that of conventionally processed polymethylmethacrylate (PMMA) resin. Materials and Methods: An impression of an aluminum maxillary edentulous arch was made with a condensation silicone impression material (Denture Elasticon) to fabricate a gypsum master cast that was replicated as a silicone mold. A maxillary complete denture with acrylic teeth was waxed to full contour on the master cast and replicated to make 40 wax dentures. ERA attachments cast in metal (Rexillium) with indices milled into the centers were waxed into 3 positions in each denture for recording dimensional measurements of the wax denture. Ten dentures were allocated to each of 4 groups; Group 1 was processed using conventionally processed PMMA (Microlon), Group 2 used injection-molded PMMA (SR-lvocap), Group 3 employed injection-molded nylon (Valplast), and Group 4 used injection-molded styrene (Northern). All processed specimens were stored at room temperature (25°C, ambient humidity) for 1 week (while still on the master cast) before anteroposterior and cross-arch measurements were made using the ERA reference points with a digital caliper. After separation from the master cast and following water storage at 37°C for 7 days additional measurements were made. Results: An analysis of the results showed that the effect of processing was not the same for the 3 dimensions studied, regardless of which dimension was considered (p 〈 0.0001). The pattern of dimensional changes associated with the material type was not the same between the wax and processing stages as it was for the change between the processing and decasting stages (p 〈 0.0001). Conclusions: Processing the denture base materials produced unequal deformation in different dimensions (anterior-posterior and cross-arch). Each material tested also responded differently to the processing stages.

Notes: Objective: It has been speculated that amoxicillin use could be associated with enamel defects, but there have been few studies of this possible relationship. This study assessed the association between amoxicillin use during the first year of life and primary tooth fluorosis. Methods: Subjects (n=490) were recruited at birth and followed prospectively with a series of questionnaires to gather information on fluoride intake and amoxicillin use. Primary tooth fluorosis was assessed by calibrated examiners at approximately 5 years of age. Results: Amoxicillin use for 6 weeks to 3 months and 3 months to 6 months significantly increased the risk for fluorosis of primary second molars in bivariate analyses. However, after controlling for fluoride intake, the adjusted risks of fluorosis were not significant for amoxicillin use. No other antibiotics were significantly associated with fluorosis in the bivariate analyses. In multivariate analyses with logistic regressions, only fluoride intake was statistically significantly related to fluorosis. Conclusion: Fluoride exposure was the sole predictor of primary tooth fluorosis in a multivariate model. However, bivariate results suggest that amoxicillin could play a contributing role in the development of primary tooth fluorosis, especially for children exposed to lower levels of fluoride. An investigation of the relationship between amoxicillin intake and fluorosis of permanent teeth is warranted.

Notes: Objectives: The purposes of this study were to investigate factors related to utilization of dental services during pregnancy and to assess the extent of mothers' knowledge regarding oral health during pregnancy and its effect on pregnancy outcomes.Materials and Methods: Cross-sectional data were collected from 625 women using a structured questionnaire mailed to mothers who had given birth in Johnson County, Iowa from August 2001 to March 2002. The survey assessed knowledge, behaviours, attitudes toward dental care during pregnancy, and personal, demographic and pregnancy-related factors. Variables which showed associations in bivariate analysis (p〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:03036979:JCPE739:les" location="les.gif"/〉0.1) were considered as candidates for building logistic regression models separately by domain (demographics, dental health care behaviours, lifestyle, financial variables, pregnancy-related variables, and knowledge of the possible association between oral health and pregnancy). Significant domain-specific regression results (p〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:03036979:JCPE739:les" location="les.gif"/〉0.05) were used to develop a final model using forward stepwise logistic regression analyses.Results: The overall response rate was 69%. Dental visits during pregnancy were reported by 49% of respondents. Forty-three percent were aware of the possible connection between oral health and pregnancy outcomes. In the final logistic regression analysis, factors significantly associated with reporting dental visits during pregnancy were: (1) personal factors (being married, greater frequency of visiting the dentist when not pregnant and use of inter-proximal cleaning aids); (2) financial factors (dental insurance); and (3) knowledge of the possible connection between oral health and pregnancy outcomes.Conclusions: There was limited knowledge of the possible relationships between oral health and pregnancy outcomes in a fairly homogeneous population of women who were of relatively high socioeconomic standing. This study suggests that better education of the importance of dental care before and during pregnancy is needed.