美白剂对正畸后脱矿着色牙齿的硬度影响

目的 使用常用的美白剂治疗正畸后脱矿着色的牙齿，观察美白剂对牙齿硬度的影响。 方法 选取因正畸拔除的前磨牙120颗，建立早期脱矿着色模型，分为4组：Opalescence美白剂（A组）、Beyond美白剂（B组）、氟化钠（C组），空白对照组（D组）。观察色阶的变化和釉质显微硬度的变化。 结果 比色板比色：各组色阶值随着时间变化呈逐渐降低再升高的趋势；各组间·时间点比较色阶值差异有统计学意义（P＜0.05）。釉质表面显微硬度值（surface microhardness value，SMV）：A组SMV值随时间的变化呈现先升高再降低的趋势，其余3组SMV值随时间变化增加后趋于平稳；组间比较：除A组与C组差异无统计学意义（P＞0.05），其余各组间的差异有统计学意义（P＜0.05）。 结论 Opalescence美白剂和Beyond美白剂均可以使正畸脱矿牙发生再矿化，Opalescence Boost美白剂对釉质矿化程度略高于Beyond美白剂。

Effect of tooth-whitening products on hardness of demineralized and stained teeth after orthodontic treatment

Objective To observe the effect of tooth-whitening products on the hardness of demineralized and stained teeth after orthodontic treatment.Methods In total,120 premolars extracted due to orthodontic treatment were used to establish early demineralization models. They were randomly divided into four groups(n=30): Opalescence tooth-whitening products group(group A), beyond tooth-whitening products group(group B), duraphat group(group C), and blank control group(group D). The changes in color scale and enamel microhardness were estimated.Results Colorimetric palette: The color scale values of each group gradually decreased and then increased with time, and the difference in color scale values in time points between groups was statistically significant(P＜0.05). Surface microhardness value(SMV): The change of SMV value of group A showed a trend of initial increasing and then decreasing with time, and SMV values in the other three groups increased initially with time and then tended to be stable. Comparison between groups showed that except the absence of statistical differences between group A and group C, the difference between the remaining groups was statistically significant(P＜0.05).Conclusion Opalescence Boost teeth-whitening products and beyond teeth-whitening products can remineralize the demineralized teeth.Opalescence Boost teeth-whitening products have a slightly higher degree of enamel mineralization than Beyond teeth-whitening products.