Use of bulk fill resin composite and universal adhesive for restoring primary teeth after selective carious tissue removal to soft dentin: A randomized clinical trial

Purpose: To investigate the survival of adhesive restorations after selective carious tissue removal to soft dentin in primary molars. Methods: This two-arm randomized clinical trial included 62 subjects (5.9 years ± 1.7) and 144 primary molars presenting deep active dentin carious lesions. The sample was randomly assigned based on restorative material: universal adhesive (Scotchbond Universal) plus bulk fill resin composite (Filtek Bulk Fill Posterior Restorative) and resin-modified glass-ionomer cement (Vitremer). Two operators performed all restorative procedures. Restorations were evaluated at 6, 12, and 18 months using the FDI World Dental Federation criteria. Survival estimates for restorations' longevity were evaluated with Kaplan-Meier method. Multivariate Cox regression analysis with shared frailty was used to assess the factors associated with failures (P< 0.05). Results: Restorative material did not influence the restorations' survival (HR 1.56 95% CI 0.78-3.13; P= 0.12). The survival rates at 18 months of follow-up were 62.9% and 76.8% (AFR: 26.6% and 16.1%) for resin-modified glass-ionomer cement and bulk fill resin composite restorations, respectively (long-rank P= 0.14). Boys had higher risk of failure in their restorations (HR: 2.64, 95% CI: 1.29-5.40). Restorations performed by a less experienced operator had 3.26 times more risk of failure (P= 0.001).