EFFECT OF TWO DIFFERENT BLEACHING TECHNIQUES ON THE MICROHARDNESS AND SURFACE ROUGHNESS OF TWO BULK-FILL COMPOSITE MATERIALS: AN IN VITRO STUDY

Abstract

Patients demand for frequent whitening of teeth, with different bleaching materials. The most common bleaching chemical used are carbamide and hydrogen peroxide. This study examines the effects of different bleaching regimens by the evaluation of surface roughness (Ra) and microhardness of two bulk-fill composite materials. Sixty disk-shaped (10 mm x 4 mm) specimens of either Filtek bulk-fill or Tetric N-Ceram bulk-fill were used. These specimens were casually assigned in five main classes in line with the restorative material present. All specimens were measured for their microhardness and Ra values (Baseline-T1). Each group was encountered with two dissimilar bleaching regimens, first refers to in-office bleaching using Opalescence Boost 40%, and at-home bleaching using Opalescence 20%. Statistical analysis was made via Statistical Package for Social Sciences version 23.0 at a significance level of p ˂0.05. Findings of the study indicated significant alterations in the microhardness when exposed to at-home bleaching agent. While, in the Ra values no significant alterations were found between the groups except for versus in-office bleaching in Surface Arithmetical mean height (SA) for Tetric N-Ceram. The study concludes that surface roughness and microhardness of bulk fill composite resin were affected by bleaching agents.

Keywords

• bleaching techniques
• composite materials
• microhardness, resin
• vitro study