Surface Properties of Enamel after Using Different Bleaching Agents

Abstract

The aim of this study was to investigate the effect of non-peroxide bleaching agents on microhardness and surface topography of enamel surface in comparison with peroxide based bleaching agents. A total of forty teeth were used in this study. Teeth were divided into two equal groups of twenty teeth each according to the bleaching agent used either in-office or at-home bleaching. Each group was divided into 2 equal subgroups of ten teeth each according to the material used into peroxide containing or non-peroxide-containing bleaching agents. Using diamond stone, a groove of one mm depth was done dividing the labial surface of each tooth longitudinally into 2 halves, one half was used to measure microhardness as a control while the same measurements were done on the other half after bleaching agent application. Two representative samples of each subgroup were used for Ultra-morphological examination of the treated enamel surface using Scanning Electron Microscope (SEM). Peroxide based at-home bleaching agent recorded the highest hardness % change followed by non-peroxide based in-office bleaching agent then peroxide based at-home bleaching agent meanwhile peroxide based in-office bleaching agent recorded the lowest change value. The non-peroxide bleaching agents (in office and at home) adversely affected enamel micro hardness. The enamel surface topography was affected more by the non-peroxide based bleaching agent.