Hydrogen Peroxide Tooth Whitening Agent Effect on the Nanomechanical Properties of Enamel

A pleasing smile can be considered part of an attractive appearance and having “whiter" teeth is perceived as an integral part of achieving this. Tooth whitening is a conservative, relatively quick and inexpensive option that uses bleaching agents such as hydrogen peroxide at various concentrations that have been marketed for in-office and at home use. The aim of this study was to assess the effects of 30% hydrogen peroxide on the nanomechanical properties and the protein content of enamel. The effect of bleaching with 30% hydrogen peroxide for 30 minutes and 10% Carbamide peroxide for 8 hours on the mechanical properties of enamel was investigated. This was determined by measuring the hardness and the elastic modulus of twelve sound enamel samples using nanoindentation testing with a Brecovich tip at 250 mN and 25mN force, before and after bleaching. The microhardness tests showed no statistically significant difference in the mean values of the elastic modulus and the hardness of enamel samples following exposure to the bleaching agents. The results obtained from this study showed that bleaching sound enamel with a 30% hydrogen peroxide for 30 minutes or 10% Carbamide peroxide for 8 hours does not affect the microhardness of enamel.