Effect of a Home Bleaching Gel Containing Chitosan and Theobromine on Tooth Surface Roughness, Microhardness, and Colour Change

This study aimed to evaluate the effect of experimental bleaching gels containing chitosan and theobromine and compare their performance in terms of tooth surface roughness, microhardness, and colour change with the bleaching gels BioWhiten ProHome and FGM Whiteness Perfect. One hundred and forty-four upper central incisors were used for microhardness, surface roughness, and colour change analyses (n = 12). Prior to bleaching, surface roughness was measured using a profilometer, microhardness was analysed using a Vickers hardness test, and colour was measured using a spectrophotometer. For Group 1, the treatment consisted of an experimental gel containing chitosan-theobromine (16% CP); for Group 2, it was an experimental gel containing chitosan-theobromine (6% HP); for Group 3, it consisted of BioWhiten ProHome (6% HP); and for Group 4, it consisted of FGM Whiteness Perfect (16% CP). Microhardness and surface roughness tests were performed under the same conditions before bleaching, after bleaching, and 14 days after the initial treatment. Colour analysis was performed before the bleaching, during the application, 24 h after bleaching, and at 7 and 14 days after treatment. <i>p</i> < 0.05 was considered significant. No statistically significant increase in microhardness values after bleaching was detected in any group (<i>p</i> > 0.05), effective bleaching was detected in all groups, and the highest efficacy was observed in Group 4 (<i>p</i> < 0.05). The experimental gels containing theobromine and chitosan resulted in effective bleaching and did not exert any negative effects regarding surface roughness or microhardness.