正畸多次酸处理后牙釉质表面的扫描电镜观察

Observations of the enamel surfaces of teeth after acid etching for several times:scanning electron microscope study.

目的：通过扫描电镜观察正畸多次酸处理后牙釉质表面的结构变化。方法：以正畸临床即将拔除的正常第一双尖牙为实验样本，分为实验组和对照组。应用５０％ 的磷酸处理牙齿的颊面，时间为６０ｓ。对实验组样本分１、２、３ 次粘结托槽。按所设计的酸处理与粘结托槽的次数拔除该牙并固定，扫描电镜下进行观察。结果：镜下的观察显示，第一次酸处理后只是部分釉柱的轻度脱钙，蜂窝样结构少而不均匀。第二次酸处理后牙釉质表面蜂窝样结构密集而规则。经一、二次粘结后牙釉质表面残留的树脂均比较少，第三次粘结后牙釉质表面相对有较多的树脂残留。结论：第二、三次粘结托槽，仍会获得较好的机械性粘合。

Objective: The purpose of this study was to investigate the enamel surface changes of teeth after acid etching for several times.Methods:First premolars that would be extracted according to the therapeutic schedule were used in this study as samples. These teeth were etched with 50% phosphoric acid for 60 seconds.The structure of the enamel surface of the teeth after 1.2.3. times of acid etching and bracket adhesion was observed with scanning electron microscope.Results:These observations showed that areas of slight decalcification were limited to some enamel rod after the acid etching for the fird time and the number of cellular structure was low. On the contrary,relatively high density and regular shape were found to be the characteristic of the cellular structure after the acid etching for the second time.Compared to the bracket adhesion for the first two times,there was much more remaining resin on the enamel surface for the third time.Conclusions:The mechanic intensity remains high for the bracket adhesion of the second and third times.