Randomized clinical trial of adhesive restorations in primary molars. 18-month results.

PURPOSE: To evaluate the clinical performance of adhesive restorations of resin composite and resin-modified glass-ionomer cements in primary molars.

METHODS: This randomized clinical trial included subjects (5-9 year-old children) selected at two university centers (UFRGS and UNIFRA). The sample consisted of 132 primary molars presenting active cavitated carious lesions (with radiographic involvement of the inner half of the dentin), located on the occlusal and occlusal-proximal surface. The sample was randomly divided into three groups, according to the restorative material: (G1) universal restorative system (Adper Single Bond 2 system and Filtek Z350); (G2): Resin-modified glass-ionomer cement (Vitremer); and (G3): Low shrink restorative system (Filtek P90). The restorations were clinically and radiographically followed every 6 months for up to 18 months using the USPHS modified criteria for clinical evaluation. Survival estimates for restoration longevity were evaluated using the Kaplan-Meier method. Log-rank test (P< 0.05) was used to compare the differences in the success rate according to the type of the restorative material.

RESULTS: The type of restorative material used did not influence the longevity of the restorations. After clinical follow-up, there was no statistical difference in the rates of success for the three materials used to restore active cavitated carious lesions in primary molars. The survival rates for the follow-up were similar regarding the number of restored surfaces and the caries removal technique (partial or complete). Mean estimated time of survival was 17.2 months (95% CI: 16.7-17.7). Estimated survival rates of the restorations were 100%, 98%, 88% and 65% at 1, 6, 12 and 18 months of clinical evaluations, respectively.