Stainless steel crown vs bulk fill composites for the restoration of primary molars post-pulpectomy: 1-year survival and acceptance results of a randomized clinical trial

Background: A key factor for the success and longevity of the endodontic treatment is sealing of the cavity after restorative treatment. Aim: The aim of this randomised clinical trial was to evaluate the 1-year survival of endodontic treatment in primary molars restored with stainless steel crowns (SSCs) and bulk fill composite resin (BF). As a secondary outcome, the acceptance of both children and parents was evaluated. Design: Ninety-one 3- to 8-year-old children with at least one primary molar requiring endodontic treatment were selected. Participants were randomized to SSC or BF and evaluated after 1, 3, 6, and 12 months. An acceptance questionnaire was completed immediately after the treatment. The primary outcome was the endodontic treatment success, evaluated in the intention-to-treat (ITT) population using the Kaplan-Meier and non-inferiority Cox regression analyses, with a non-inferiority limit of 15%. Sensitivity analysis between the success rates after 1 year was performed using Miettinen-Nurminen's method. The Mann-Whitney test was used to compare the treatment acceptance (α = 5%). Results: The survival rate after 1 year was BF = 75% and SSC = 88% (HR = 1.41; 90% CI 0.57-3.43). ITT analysis showed a success rate of BF = 86.7% and SSC = 82.6% (RR = 0.95; 0.78-1.16). The non-inferiority hypothesis between the survival of endodontic treatment could not be proved in both analyses (P >.05). The overall acceptance scores did not differ between the restorative groups (P >.05). Conclusion: This study failed to show non-inferiority of BF compared with the SSC. The materials were well accepted by both children and their parents.