Effects of lesion size on the 30-month clinical performance of restorations with bulk fill and a regular nanofilled resin composite in noncarious cervical lesions

Abstract

Objective: The aim of this double-blind, randomized controlled trial was to evaluate the in uence of the occlusogingival distance (OGD) in noncarious cervical lesions (NCCLs) on the clinical performance of a regular bulk-ll resin composite and a regular nano lled resin composite.Materials and Methods: 140 NCCLs in 77 participants were randomly divided into four groups (n=35), according to OGD (1.5 mm±10% or 3 mm±10%) and resin composites (Filtek Bulk Fill Posterior [B] or Filtek Z350 XT [C]), namely: 1.5 mm-B, 1.5 mm-C, 3 mm-B, and 3 mm-C. The restorations were bonded using a two-step self-etch adhesive (Clear l SE Bond), applied following the manufacturer's instructions. Restorations were polished 1 week after placement. Two experienced and calibrated examiners evaluated the restorations using modi ed US Public Health Service criteria at baseline (7 days) and after 6, 12, 18, 24 and 30 months. Statistical analyses were carried out using Kruskal-Wallis, Friedman's repeated measures analysis of variance and the Wilcoxon Signed rank test (α = 0.05).Results: After 30 months, the recall rate was 94.2%. Eight restorations were lost (3 for 1.5 mm-C, 2 for 1.5 mm-B, 1 for 3 mm-C and 2 for 3 mm-B). All groups resulted in a signi cantly worse marginal discoloration and surface texture at 30 months in comparison with the baseline (one week). Conclusion:The restorations performed with both resin composites produced clinically acceptable restorations. The OGD of NCCLs of did not in uence the clinical performance of restorations.Clinical signi cance: The regular bulk-ll material showed excellent clinical behavior in NCCLs of different sizes, similar to the regular nano lled resin composite.