Assessment of Surface Roughness and Compressive Strength of Resin-Based Composite Using Different Types of Bleaching Protocols

Abstract: This study aims to assess surface roughness and compressive strength of resin-based composite using different types of bleaching protocols. Three different bleaching protocols were applied to determine their effect on composite resin's compressive strength and surface roughness. Eighty composite resin samples were prepared using metal molds; forty samples (2 mm in height and 8 mm in diameter) for surface roughness evaluation and the other forty samples (6 mm in height and 4 mm in diameter) for compressive strength. Every forty samples were divided into four groups. In group 1 (n = 10), samples were stored in deionized water at 37°C for two weeks as control, in group 2 (n =10), samples were subjected to home bleaching with 22% carbamide peroxide (CP), in group 3 (n = 10) samples were subjected to home bleaching with 14% hydrogen peroxide (HP), and in group 4 (n =10) samples were subjected to bleaching with 25% hydrogen peroxide (HP in-Office) in a dental clinic. After bleaching, surface roughness and compressive strength of groups 2, 3, and 4 were measured. After applying bleaching protocols, a similar increase in the enamel surface roughness of all samples was observed; however, this increase was not statistically significant compared to the control group. The CP-treated group had the highest surface roughness. All three bleaching protocols resulted in a decrease of compressive strength of the composite compared to the control group, and the minimum compressive strength belonged to the HP-treated group, followed by HP inOffice group and CP group, respectively. According to the results of this study, there was an increase in surface roughness using different types of bleaching protocols (22% CP and 14% HP) at-Home bleaching technique and (25%) in-Office HP bleaching with no significant difference between them, while all three bleaching protocols reduced the compressive strength of the composite with no significant difference.