Bleaching effect on surface roughness and microhardness of dentin

Abstract

The main objectives of this study were to determine the effects of the bleaching solutions on the surface characteristics of dentin namely, microhardness and surface roughness. Sixteen dentin samples were prepared for the measurements. Teeth mounted in an acrylic resin blocks for microhardness measurements and surface roughness. The bleaching was performed by immersion of each sample in (35%) hydrogen peroxide at (37)°C in an incubator for a period of one hour. Vicker'smicrohardness instruments used for microhardness measurements and profilometertesting machine was used to evaluate surface Toughness. Two measurements were taken from each samples one before and the other after bleaching procedure. The data were collected and analyzed using analysis of variance and t-test, The results showed that the microhardness of dentin is greater before bleaching than the mean after bleaching procedures. This indicated that the bleaching solution used in this study reduced the microhardness of the dentin in vitro. There are slight changes in the mean value of the surface roughness of dentin after bleaching, which is statistically not significant.