Effects of bleaching gel containing TiO 2 and chitosan on tooth surface roughness, microhardness and colour

Background This study aimed to evaluate the effects of an experimental bleaching gel made with TiO 2 and chitosan, along with the Opalescence Boost PF and Philips Zoom bleaching agents, on tooth surface roughness, microhardness and colour. Materials and Methods The experimental gel, containing 6% hydrogen peroxide (HP), was evaluated against the two existing treatments, which incorporate 40% and 25% HP. For colour evaluation, 36 human premolar teeth were divided into three groups (n = 12). For surface roughness and microhardness evaluation, 72 bovine incisor samples were divided into six groups (n = 12). Data on colour alteration were analysed with the CIEDE2000 formula. Surface roughness was measured using a profilometer, and microhardness was measured with a Vickers hardness tester. ANOVA was used for statistical analysis. Results There were no statistically significant differences among the groups for surface roughness, microhardness values or colour change after bleaching ( P  > 0.05). The lowest bleaching efficacy was observed for the 40% HP agent, and the highest efficacy was observed for the 25% HP agent ( P  < 0.05). Conclusions An experimental 6% HP gel containing TiO 2 and chitosan provided effective bleaching without adverse effects on tooth surface roughness or microhardness. The use of TiO 2 with chitosan can provide clinicians with positive results.