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This practice-based study investigated the performance of a large set of anterior composite restorations placed by a group of 24 general practices. Based on data from electronic patient files, the longevity of 72,196 composite restorations was analyzed, as placed in 29,855 patients by 47 general dental practitioners between 1996 and 2011. Annual failure rates (AFRs) were calculated, and variables associated with failure were assessed by multivariate Cox regression analysis with shared frailty for 2 age groups (5 to 24 y and ≥25 y). The observation time of restorations varied from 2 wk to 13 y, with a mean of 4.8 y, resulting in a mean AFR of 4.6% (95% confidence interval [95% CI], 4.5% to 4.6%) at 5 y. Among dentists, a relevant variation in clinical performance of restorations was observed, with an AFR between 2% and 11%. The risk for restoration failure increased in individuals up to 12 y old, having a 17% higher risk for failure when compared with the age group of 18 to 25 y (hazard ratio, 1.17; 95% CI, 1.03 to 1.34), and for the age group >65 y, having a 81% higher risk for failure when compared with 25 to 35 y (hazard ratio, 1.81; 95% CI, 1.66 to 1.98). In both multivariate models, there was a difference in longevity of restorations for different teeth in the arch, with fillings in central incisors being the most prone to failure and replacement. It was concluded that anterior composite restorations placed by general dental practitioners showed an adequate clinical performance, with a relevant difference in outcome among operators. [ABSTRACT FROM AUTHOR]

There are no prospective studies investigating the effects of sugar-related feeding practices on changes in dental caries from early childhood to young adulthood. The aim of this study was to assess whether sugar-related feeding practices affect dental caries between the ages of 6 and 18 y. This birth cohort study was initiated in 1993 in Pelotas, Brazil. There were 3 dental clinical assessments; at ages 6 y (n = 359), 12 y (n = 339), and 18 y (n = 307). Sugar-related feeding practices were assessed at ages 4, 15, and 18 y. Covariates included sex and life course variables, such as family income, breast-feeding, mother's education, regularity of dental visit, and child's toothbrushing habits. Group-based trajectory analysis was performed to characterize trajectories of time-varying independent variables that had at least 3 time points. We fitted a generalized linear mixed model assuming negative binomial distribution with log link function on 3-time repeated dental caries assessments. One in 5 participants was classified as "high" sugar consumers, and nearly 40% were "upward consumers." "Low consumers" accounted for >40% of the sample. High and upward sugar consumers had higher dental caries prevalence and mean DMFT in all cohort waves when compared with low sugar consumers. Caries occurred at a relatively constant rate over the period of study, but in all sugar consumption groups, the increment of dental caries was slightly higher between ages 6 and 12 y than between 12 and 18 y. Adjusted analysis showed that dental caries increment ratio between ages 6 and 18 y was 20% and 66% higher in upward and high sugar consumer groups as compared with low consumers. The higher the sugar consumption along the life course, the higher the dental caries increment. Even the low level of sugar consumption was related to dental caries, despite the use of fluoride. [ABSTRACT FROM AUTHOR]

This study aimed to assess the prevalence of use and need for dental prostheses (UNDP) by individuals at age 24 and their life-course determinants. A representative sample (n = 720) of all 5914 births occurring in Pelotas in 1982 were prospectively investigated, and the UNDP were assessed in 2006. Exploratory variables included demographic and socio-economic, oral health, and dental service utilization patterns during the lifecourse. The prevalence of UNDP was 2.1% and 29.7%, respectively. Multivariable Poisson regression analysis showed that low socio-economic status through the life-course [Prevalence Ratio (PR) = 1.56 (95% CI: 1.08-2.26)], lower maternal schooling in childhood [PR 2.79 (1.34-5.79)], no oral hygiene instruction by a dentist at age 15 [PR 1.64 (1.11-2.41)], and caries presence at age 15 (high DMFT tertile) [PR 2.90 (1.98-4.24)] were associated with prosthetic treatment needs. These results support the hypothesis that life-course socio-economic, behavioral, and clinical determinants are associated with the need for dental prostheses. [ABSTRACT FROM AUTHOR]

It is known that stem cells from exfoliated deciduous teeth (SHED) can be induced to differentiate into odontoblasts. However, the nature of dentin-derived morphogenic signals required for dental pulp stem cell differentiation remains unclear. The hypothesis underlying this work is that dentin-derived Bone Morphogenetic Proteins (BMP) are necessary for the differentiation of SHED into odontoblasts. We observed that SHED express markers of odontoblastic differentiation (DSPP, DMP-1, MEPE) when seeded in human tooth slice/scaffolds and cultured in vitro, or implanted subcutaneously into immunodeficient mice. In contrast, SHED cultured in deproteinized tooth slice/scaffolds, or scaffolds without a tooth slice, do not express these markers. SHED express the BMP receptors BMPR-IA, BMPR-IB, and BMPR-II. Notably, blockade of BMP-2 signaling inhibited the expression of markers of odontoblastic differentiation by SHED cultured in tooth slice/ scaffolds. Collectively, this work demonstrates that dentin-derived BMP-2 is required to induce the differentiation of SHED into odontoblasts. [ABSTRACT FROM AUTHOR]

This double-blind randomized clinical trial evaluated the efficacy and safety of two carbamide peroxide concentrations used in at-home vital bleaching. Ninety-two volunteers with a shade mean of C1 or darker for the six maxillary anterior teeth were randomized into two balanced groups (n=46) according to bleaching agent concentration: 10% (CP10) or 16% (CP16) carbamide peroxide. The patients were instructed to use the whitening agent in a tray for two hours once a day for three weeks. Shade evaluations were done with a value-oriented shade guide mad a spectrophotometer at baseline and one week post-bleaching (four-week evaluation). Tooth sensitivity was measured daily using a scale ranging from 0 (no sensitivity) to 4 (severe sensitivity). At the end of the study, the volunteers filled out a questionnaire with seven questions aimed to give their opinion about the adopted treatment regimen. Both carbamide peroxide concentrations resulted in significantly lighter teeth at the four-week evaluation compared to the baseline for all color parameters (p<0.0001) and shade median (p<0.001). There was no significant difference between the two groups in terms of shade change difference with either the spectrophotometer (p=0.1) or the shade guide (p=0.7). Also, no statistically significant difference was found in relation to ΔL* (p=0.7), Δa* and ΔE* (p=0.5). A significant reduction in yellowness (Δb*) was observed for CP16 compared to CP10 (p=0.05) in crude analysis, which disappeared after controlling for b* parameter at baseline. The group treated with CP16 experienced more tooth sensitivity during the first (p=0.02) and third (p=0.01) weeks of treatment compared to the CP10 group. However, no major difference was observed (p=0.09) when the degree of tooth sensitivity between groups was compared. Both 10% and 16% carbamide peroxide concentrations were equally effective and safe for a three-week at-home tooth-bleaching treatment. [ABSTRACT FROM AUTHOR]

Purpose: This in vitro study tested tensile bond strength to enamel and dentin and the flexural modulus of three resin cements. It also determined the influence of these properties on the fracture resistance of teeth restored with ceramic inlays. Materials and Methods: Initially, 10 standard ceramic discs were bonded to enamel using the following resin cements: Enforce (E), RelyX ARC (RX) and Fill Magic Dual Cement (FM). After seven days of storage, the specimens were subjected to tensile forces at a crosshead speed of 0.5 mm/minute until fracture. The enamel was then ground and the ceramic disks were bonded to dentin. The flexural modulus of each type of resin cement was calculated based on the straight-line tension-deformation curve using the three-point flexure method. For resistance to fracture, 40 sound maxillary premolars were randomly divided into four groups (n=10). Three groups were submitted to preparations and restored with ceramic inlays bonded with the same resin cements used during the tensile test (n=10). Intact teeth were used as the control group. The specimens were subjected to compressive axial loading at 0.5 mm/minute using a 10-mm steel ball until fracture. Results: Statistical analysis revealed that, for all cements, the bond strength to enamel was significantly higher (p<0.05) than that obtained in dentin, in both substrates, RX and FM showed higher bond strengths than that obtained for E (p<0.05). In relation to flexural modulus, FM had the lowest and E the highest flexural modulus; whereas, RX differed from the other two (p<0.05). The teeth with inlays that were bonded using RX, and E had a significantly higher (p<0.05) fracture resistance than those where the inlays were bonded with FM but without recovering the resistance observed for the control group (intact teeth). Conclusion: The three resin cements had different mechanical properties. A higher flexural modulus usually resulted in improved resistance to fracture for the ceramically restored teeth. [ABSTRACT FROM AUTHOR]

This study evaluated in vitro and in situ the potential adverse effects of 10% carbamide per oxide on human enamel using microhardness calcium loss and surface morphology analysis. Twenty-four enamel slices (4 mm2) were obtained from recently extracted premolars. The specimens were polished under water-cooling down to 1,200-grade sandpaper. After initial microhardness readings (100g), the specimens were randomly divided into two groups for in situ and in vitro specimens were stored in deionized water and the in situ specimens, included in an intra-oral appliance, were placed in the oral cavity of four volunteers. these cycling sequences took place for 14 days. Upon conclusion of the bleaching treatment, new microhardness readings were performed on all specimens. Calcium dosage was assessed from the bleaching gel collected after initial exposure on day one, then from gel collected between days two and seven and gel collected between day eight and 14 using an atomic absorption spectrophotometer. Surface morphology was observed from two non-treated control specimens and two specimens of each experimental bleached group under SEM evaluation. Statistical analysis (ANOVA and Tukey test) disclosed that specimens bleached in situ showed similar microhardness to unbleached specimens and had statistically higher (p<0.01)hardness than in vitru bleached specimens. The loss if calcium in the vitru conditions. SEM micrographs demonstrated that surface alterations were more pronounced in the in vitro condition. The adverse effects of carbamide peroxide on enamel were evident in specimens bleached in vitro but were not seen in situ. The presence of saliva could prevent the demiralizing effects of bleaching gel in situ. [ABSTRACT FROM AUTHOR]

This study evaluated in vitro the influence of five solutions used to treat cavity preparations on microleakage of amalgam restorations. Seventy-two standard Class V cavities were prepared in buccal and lingual surfaces of 36 recently extracted human third molars. The cervical wall was located in cementum and the occlusal wall was located in enamel. Specimens were randomly divided into six groups (n=12) according to the solution employed to treat the cavities: Group I-2.5% sodium hypochlorite; Group II-Calcium hydroxide solution; Group III-1.23% Acidulated phosphate fluoride; Group IV-2% digluconate of chlorhexidine; Group V-anionic detergent solution (1.25% sodium lauryl sulfate) and Group VI-control group. The solutions were applied for one minute, followed by washing and drying. Two coats of copal varnish were applied in each cavity. The cavities were filled with capsuled amalgam GS-80 (SDI). After finishing and polishing, the specimens were submitted for thermal cycling followed by immersion in methylene blue. Then, the specimens were sectioned and microleakage was evaluated based on a standard ranking under magnification (40x). Data were subjected to statistical analysis using non-parametric tests. Results of the study concluded that leakage was higher in cementum than enamel (p<0.01). The substances employed have no influence on microleakage except for sodium hypochlorite, which increased leakage values in enamel (p<0.05). [ABSTRACT FROM AUTHOR]

This study compared marginal leakage of Class II cavities with gingival margin in cementum using different technique~ Twenty-four recently extracted third molars were used. Proximal standard box cavities were prepared in both mesial and distal surfaces. The gingival margin was located apical to the cemento-enamel junction. All the preparations and restorations were performed by the same operator. Standard cavities were randomly divided into three groups (n=16) and restored as follows: Group 1-light-cured composite resin; Group 2--self-cured composite resin + light-cured composite resin and Group 3-amalgam + light-cured composite resin. After polishing, the teeth were thermocycled and their gingival margins exposed to dye. Specimens were sectioned and leakage scores observed in accordance with a standard ranking. Data were subjected to statistical analysis (Kruskal-Wallis). Results showed that the amalgam/resin composite combination demonstrated the least leakage. [ABSTRACT FROM AUTHOR]

This study evaluated the influence of caries-detection dyes on the in vitro tensile bond strength of adhesive materials to sound dentin. Caries-free human molars were ground to expose superficial dentin. Two dyes (a commercial 0.5% basic fuchsin in propylene glycol and Cari-D-Tect) were applied to sound dentin and rinsed. Subsequently, the dentin was etched with phosphoric acid (35%) and rinsed, leaving a moist dentin surface. The adhesive (Prime & Bond 2.0) was applied in two layers and light cured. A composite (TPH Spectrum), a compomer (Dyract), and a hybrid ionomer (Advance) were used to prepare the bond-strength specimens with a 3-mm-in-diameter bonding area. Control groups were made without use of dyes. Six specimens were prepared for each group. After 24 hours in distilled water, tensile bond strength (MPa) was measured using a testing machine. Analysis of variance was used to evaluate the data. Without dyes, bond strengths of TPH Spectrum and Dyract with Prime and Bond 2.0 were similar and both values were significantly (P < 0.05) higher than that of Advance with Prime & Bond 2.0. Dyes for caries detection reduced the bond strength of TPH Spectrum and Dyract but not Advance when used with Prime and Bond 2.0. [ABSTRACT FROM AUTHOR]