Shear bond strength of a self-adhering flowable composite when used for lingual retainer bonding

Objective The goal of this work was to assess the shear bond strength (SBS) and fracture mode of a self-adhering flowable composite when used after thermocycling for lingual retainer bonding. Materials and methods A total of 80 human mandibular incisor teeth were categorized into four equal groups: group 1: Vertise™ Flow (VF) without acid etching; group 2: VF with acid etching; group 3: VF with a self-etching bonding agent accompanied by an additional acid etching; group 4: Transbond LR control. Either VF or Transbond LR was applied to the lingual surface of the teeth by packing the material into cylindrical plastic matrices to simulate the lingual retainer bonding area. After all teeth were thermocycled (5000 cycles, 5 and 55 °C), fracture modes were examined under ×20 magnification. The SBS data were assessed via analysis of variance (ANOVA) and Tukey’s tests. Fracture modes were analyzed by the χ 2 test at a significance level of 0.05. Results Statistically significant differences in SBS values between groups (p