Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, Av. Prof. Lineu Prestes, 2227, Cidade Universitária, São Paulo, SP, 05508-900, Brazil.
Post-graduate Programme in Dentistry, School of Dentistry, Paulista University-UNIP, Av. Dr Bacelar 1212, Vila Clementino, São Paulo, SP, 04026-002, Brazil.
Clin Oral Investig. 2018 Mar;22(2):961-970. doi: 10.1007/s00784-017-2175-2. Epub 2017 Jul 8.
The objective of the present study is to evaluate the effects of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on bleached enamel.
A bleaching agent (35% hydrogen peroxide) was applied, 4 × 8 min on premolar teeth (n = 8). A CPP-ACP paste was applied for 7 days. Prior and post-treatment, microtomography images were obtained and 3D regions of interest (ROIs) were selected, from outer enamel, extending to 110.2-μm depth. CT parameters of structure: thickness (St.Th), separation (St.Sp), and fragmentation index (Fr.I.) were calculated for each (ROI). Data was submitted to paired t tests at a 95% confidence level. The samples were evaluated at 3000 to 100,000 magnification. Quantitative analysis of enamel mineral content was also determined by SEM EDX.
There was a significant increase in structure thickness and calcium content. The phosphorus content increased after bleaching. There was also a decreased separation and fragmentation index on the outer enamel to a depth of 56.2 μm (p < 0.05). There were no changes at 110.2-μm depth for the bleaching CPP-ACP association. A covering layer and decreased spaces between the hydroxyapatite crystals appeared around the enamel prisms, 7 days after the CPP-ACP application.
The application of a CPP-ACP provides a compact structure on the enamel's outer surface, for 7 days, due to calcium deposition. CT parameters seem to be a useful tool for mineralizing and remineralizing future studies.
CPP-ACP neutralizes any adverse effects on enamel surface when applied during a week after bleaching and minimizes any side effects of the bleaching treatment due to a more compact structure.
本研究旨在评估酪蛋白磷酸肽-无定形磷酸钙（CPP-ACP）对漂白牙釉质的影响。
在 8 颗前磨牙上应用漂白剂（35%过氧化氢），每次 8 分钟，共 4 次。应用 CPP-ACP 糊剂 7 天。治疗前后，获取微断层扫描图像，并选择 3D 感兴趣区域（ROI），从外釉质延伸至 110.2μm 深度。计算每个 ROI 的结构 CT 参数：厚度（St.Th）、分离（St.Sp）和碎片指数（Fr.I.）。数据在 95%置信水平下进行配对 t 检验。样品在 3000 至 100000 倍放大倍数下进行评估。SEM EDX 还定量分析了牙釉质矿物质含量。
结构厚度和钙含量显著增加。磷含量在漂白后增加。在外釉质至 56.2μm 深度处，分离和碎片指数也降低（p<0.05）。在 110.2μm 深度处，漂白 CPP-ACP 联合治疗没有变化。CPP-ACP 应用 7 天后，牙釉质棱柱周围出现覆盖层和羟磷灰石晶体之间的间隙减少。
CPP-ACP 的应用可在 7 天内在牙釉质外表面形成钙沉积，使结构更加紧密。CT 参数似乎是未来矿化和再矿化研究的有用工具。
CPP-ACP 在漂白后一周内应用时可中和对牙釉质表面的任何不利影响，并通过更紧密的结构最小化漂白治疗的任何副作用。
