Performance of resin composite restorations in the primary dentition: a retrospective university-based study.

BACKGROUND: Limited data is available on variables influencing the survival of composite restorations in primary teeth. AIM: This retrospective university-based study assessed the survival and risk factors associated with failures of resin composite restorations performed in primary teeth. DESIGN: The sample was composed of 961 restorations from records of 337 patients (178 girls and 159 boys) attended in a university dental clinic. The restorations' longevity up to 48 months of follow-up was assessed using the Kaplan-Meier survival test. Multivariate Cox regression analysis with shared frailty was used to evaluate the factors associated with failures (P < 0.05). RESULTS: Mean survival time was 41.5 months (95% CI: 39.7-43.3), with 70.6% of the restorations surviving after 48 months of evaluation. The overall annual failure rate up to 48 months follow-up was 8.3%. Restorations placed in lower arch had lower survival rate than those in upper arch (HR: 1.82, 95% CI: 1.02-3.28). Restorations involving two or more surfaces had more risk of failure than restorations placed in cavities involving only one surface (HR: 2.55 95% CI: 1.34- 4.83). Girls had less risk of failure in their restorations (HR: 0.43, 95% CI: 0.19-0.96). CONCLUSION: Individual and dental variables such as gender, arch type and number of restored surfaces were associated with failure of composite restorations performed in children under daily life clinical environment.

Role of Etching Mode on Bonding Longevity of a Universal Adhesive to Eroded Dentin.

PURPOSE: To assess the immediate and six-month microshear bond strength (µSBS) of a universal adhesive applied using different etching strategies on sound and eroded dentin. MATERIALS AND METHODS: Eighty bovine incisors were polished to obtain flat buccal dentin. Forty teeth were submitted to a pH-cycling model to simulate artificial erosion (3x/day cola drink for 7 days). Teeth from both dentin conditions (sound and eroded) were randomly assigned to four groups according to the adhesive and etching approach: a universal adhesive in self-etch and etch-and-rinse modes (Scotchbond Universal Adhesive), and as controls a two-step etch-and-rinse adhesive (Adper Single Bond Plus), and a two-step self-etch adhesive (Clearfil SE Bond). Four composite restorations (Z250) were built up on each dentin surface, using the area delimitation technique. Half of the specimens were evaluated in the µSBS test after 24 h of water storage, and the other half were evaluated six months later. Data (MPa) were analyzed with three-way repeated measures ANOVA and Tukey's post-hoc tests (α = 0.05). RESULTS: The µSBS values of all adhesives significantly decreased after six months of aging (p = 0.01). Lower µSBS values were obtained in eroded dentin (p = 0.04). The universal adhesive showed similar µSBS to the self-etch adhesive used as control, irrespective of the etching strategy. However, Scotchbond Universal Adhesive applied in self-etch mode performed better than the control etch-and-rinse adhesive (p = 0.02). CONCLUSION: The universal adhesive does not provide the same bonding efficacy on eroded dentin as on sound dentin, and its performance does not depend on the etching mode.

Survival and Associated Risk Factors of Resin-based Composite Restorations in Primary Teeth: A Clinical, Retrospective, University-based Study.

PURPOSE: This clinical retrospective study evaluated the survival and risk factors associated with failures of resin-based composite restorations in primary teeth. METHODS: A total of 212 restorations in primary teeth from records of 76 high caries-risk children were included. The restorations' longevity for up to six years of follow-up was assessed using the Kaplan-Meier survival test. Multivariate Cox regression analysis with shared frailty was used to evaluate the factors associated with failures (P<0.05). RESULTS: Mean survival time was 4.3 years (95 percent confidence interval (CI) equals 4.0 to 4.6). The survival of the restorations reached 35.3 percent, up to the sixth year, with an annual failure rate of 18.8 percent. Restorations placed in teeth with pulp treatment had a lower survival rate than those in vital teeth (hazard ratio [HR] equals 2.16, 95 percent CI equals 1.02 to 4.58). Patients who did not use standard fluoride toothpaste had more risk of failure in their restorations (HR equals 6.12, 95 percent CI equals 1.47 to 25.49). CONCLUSIONS: Composite restorations placed in high caries-risk children presented limited survival after six years of follow-up. Standard fluoride toothpaste use was a protection factor, while pulp treatment was a risk factor for restoration failure.