邻面不同去釉方法对牙釉质的影响

目的:通过体外pH循环实验,找到一种临床效果较好的邻面去釉方法。方法:收集因正畸减数治疗的前磨牙50颗,沿牙体长轴纵向剖开,得到100个样本,随机分为5组。Ⅰ组为片切砂条,Ⅱ组为片切盘,Ⅲ组为片切砂条+抛光+35%磷酸,Ⅳ组为片切盘+抛光+35%磷酸,Ⅴ组为未去釉组。每组样本经过体外pH循环30 d后,采用扫描电镜及显微硬度仪检测,采用SPSS13.0软件包对数据进行统计学分析。结果:①各组的显微硬度值两两比较,Ⅰ组与Ⅱ组、Ⅲ组与Ⅳ组间无显著差异(P>0.05);Ⅰ组与Ⅲ组、Ⅰ组与Ⅳ组、Ⅱ组与Ⅲ组、Ⅱ组与Ⅳ组有高度显著差异(P<0.01);Ⅰ组与Ⅴ组、Ⅱ组与Ⅴ组、Ⅲ组与Ⅴ组、Ⅳ组与Ⅴ组间差异显著(P<0.05)。②肉眼及扫描电镜观察,Ⅲ组及Ⅳ组无明显不同,但均优于其余几组。结论:①去釉盘和去釉砂条的去釉效果无显著不同。②化学抛光组的再矿化效果优于未抛光组及对照组。③邻面去釉后釉质表面的划痕,即使经再矿化也难以恢复。

Effect of different orthodontic interproximal reduction methods on the enamel

PURPOSE: To find a suitable interproximal enamel(IER) reduction method for clinical use by pH cycles in vitro.METHODS: 50 human premolars extracted for orthodontic reasons were collected for the experiment.After removal of the roots,the crowns were split vertically into two halves with wafer-thin wheel blade.Then the 100 samples were randomly divided into 5 groups,20 samples for each group.The enamel in each group was reduced with different IER methods: group Ⅰ,stripping strip;group Ⅱ,stripping disk;group Ⅲ,stripping strip with polishing system and 35% orthophosphoric acid;group Ⅳ,stripping disk with polishing system and 35% orthophosphoric acid;group Ⅴ,no treatment control group.All the samples were treated with pH cycles in vitro for 30 days.The microhardness of enamel surface of all samples was detected by microhardness testing machine.The enamel surface morphology of microstructure was examined by scanning electron microscopy(SEM).The data was analyzed with SPSS13.0 software package.RESULTS: ①ANOVA detected statistically significant differences between groups.The post SNK-q test showed that there was no significant difference between group Ⅰ and group Ⅱ,between group Ⅲ and group Ⅳ(P>0.05);But there was significant difference between group Ⅰ and group Ⅲ,group Ⅰ and group Ⅳ,group Ⅱ and group Ⅲ,group Ⅱ and group Ⅳ(P<0.01).And there was significant difference between group Ⅰ and group Ⅴ,group Ⅱ and group Ⅴ,group Ⅲ and group Ⅴ,group Ⅳ and group Ⅴ(P<0.05).②From naked eye and SEM,there was no distinct difference between the two chemical polishing groups,but better than the others.CONCLUSIONS: ①There is no significant difference between strip and disk after IER.②Chemical polishing group is better than the others after IER.③The scratches of the enamel surface caused by IER are hardly repaired even after remineralization.