Bulk Fill Composite Resin for Non-carious Cervical Lesions: A 24-Month Randomized Clinical Study

Objective: To clinically evaluate for 24 months the restorations of caries-free cervical lesions (CFCL) made with bulk-fill composite resin.  Materials and Methods: Sixty CFCL were selected and divided into two experimental groups: Filtek Z350 (control with conventional composite resin) and Filtek BF (Bulk Fill composite resin). The restorations were evaluated according to the USPHS criteria - marginal adaptation, anatomic form, marginal discoloration, caries formation, postoperative sensitivity, and retention - at the following periods: initial, 7, 30, 180, and 720 days. The results were statistically analyzed using the Friedman ANOVA test (p < 0.05) followed by the Durbin-Conover post-test (p < 0.05). For intra-group analysis, the Wilcoxon non-parametric test was used (p < 0.05). Results: Significant differences were observed between the groups, with Bulk Fill resin showing superior clinical performance in terms of marginal adaptation, restoration discoloration, anatomic form, and especially dentin sensitivity. Regarding caries formation and retention, both groups presented similar results. Conclusion: Bulk-fill composite resins demonstrated superiority in various USPHS criteria in the treatment of caries-free cervical lesions, proving to be a promising material for this treatment context.