Thacker Minal, Chen Yi-Ning, Lin Chun-Pin, Lin Feng-Huei
Graduate Institute of Biomedical Engineering, National Taiwan University, Taipei 10051, Taiwan.
Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei 10617, Taiwan.
Int J Mol Sci. 2021 Apr 4;22(7):3759. doi: 10.3390/ijms22073759.
The available tooth whitening products in the market contain high concentrations of hydrogen peroxide (HO) as an active ingredient. Therefore, in order to curb the high HO concentration and instability of liquid HO, this study evaluated the efficacy and cytotoxicity of the bleaching gel composed of 10% calcium peroxide (CaO) and visible-light-activating nitrogen-doped titanium dioxide (N-TiO) with methyl cellulose as a thickener. Extracted bovine teeth were discolored using coffee and black tea stain solution and were divided into two groups ( = 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 Lab* values were measured pre- and post-bleaching. The N-TiO 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 (ΔL) and color difference (ΔE) increased as bleaching progressed each time in both the groups. ANOVA results showed that the number of bleaching significantly affected ΔE ( < 0.05). The formulated bleaching gel exhibits good biocompatibility and non-toxicity upon exposure to 3T3 cells. Our findings showed that CaO-based bleaching gel at neutral pH could be a stable, safe, and effective substitute for tooth whitening products currently available in the market.
市场上现有的牙齿美白产品含有高浓度的过氧化氢（H₂O₂）作为活性成分。因此，为了抑制液体H₂O₂的高浓度和不稳定性，本研究评估了以10%过氧化钙（CaO₂）和可见光激活的氮掺杂二氧化钛（N-TiO₂）组成、以甲基纤维素为增稠剂的漂白凝胶的功效和细胞毒性。用咖啡和红茶染色液使拔除的牛牙变色，并将其分为两组（n = 6）。两组的每个牙齿标本均进行三次漂白，每次漂白时进行一分钟的可见光照射。在漂白前后测量CIELAB Lab*值。在350℃煅烧的N-TiO₂通过将带隙能量从3.23 eV缩小到2.85 eV，表现出向可见光区域的转变。两组每次漂白时，亮度（ΔL）和色差（ΔE）均随着漂白进程而增加。方差分析结果表明，漂白次数对ΔE有显著影响（p < 0.05）。配制的漂白凝胶在暴露于3T3细胞时表现出良好的生物相容性和无毒性。我们的研究结果表明，中性pH值的基于CaO₂的漂白凝胶可能是市场上现有牙齿美白产品的一种稳定、安全且有效的替代品。
