Methods: To use the ultrasonic scaler,scaler,scraper and sand blast to clean the teeth,then to scan the samples with electronic microscope.Through polishing the teeth,to observe the recovery degree.

• 方法:应用超声波洁牙机、手工洁治器、龈下刮治器、喷沙等洁牙方法对离体牙进行洁治,然后对其表面做扫描电镜观察,抛光后,再观察其损伤恢复的程度。