Evaluation of The Effect of In-Office Bleaching Agent on Mechanical Properties of Different Single-Shade Resin Composites: An In-Vitro Study

Aim: This study aimed to evaluate the surface roughness and micro-hardness of five different single-shade resin composites in vitro after a bleaching treatment protocol. Material and methods: A total of fifty resin composite specimens were prepared from each single-shade resin composite (Filtek Universal [FU], Vittra Unique [VU], Omnichroma [O], Essentia Universal [EU], Charisma Diamond One [CDO]). Ten specimens were prepared from each material, for surface roughness and micro-hardness testing (n=10). After the first measurements, in-office bleaching gel was applied to the specimen surfaces three times, and each application took 15 minutes. After the bleaching protocol, the measurements were repeated, and the values were statistically analyzed using ANOVA and post hoc Bonferroni tests. Significance was evaluated at a p