The available tooth whitening products in the market contain high concentrations of hydrogen peroxide (H2O2 ) as an active ingredient. Therefore, in order to curb the high H2O2 concentration and instability of liquid H2O2, this study evaluated the efficacy and cytotoxicity of the bleaching gel composed of 10% calcium peroxide (CaO2 ) and visible-light-activating nitrogen-doped titanium dioxide (N-TiO2 ) with methyl cellulose as a thickener. Extracted bovine teeth were discolored using coffee and black tea stain solution and were divided into two groups (n = 6). Bleaching was performed thrice on each tooth specimen in both the groups, with one minute of visible light irradiation during each bleaching time. The CIELAB L*a*b* values were measured pre-and post-bleaching. The N-TiO2 calcinated at 350◦C demonstrated a shift towards the visible light region by narrowing the band gap energy from 3.23 eV to 2.85 eV. The brightness (∆L) and color difference (∆E) increased as bleaching progressed each time in both the groups. ANOVA results showed that the number of bleaching significantly affected ∆E (p < 0.05). The formulated bleaching gel exhibits good biocompatibility and non-toxicity upon exposure to 3T3 cells. Our findings showed that CaO2-based bleaching gel at neutral pH could be a stable, safe, and effective substitute for tooth whitening products currently available in the market.
Date:
2021-04-04
Relation:
International Journal of Molecular Sciences. 2021 Apr 4;22(7):Article number 3759.
