摘要目的 探讨超声洁牙不损害牙体组织的最佳频率及操作要点.方法 选择25颗离体牙,其中有一颗牙为正常对照,另24颗均有程度不同牙结石和烟斑的牙,随机分为3组:A组、B组和C组.每8颗牙1组,每组又分牙结实验组和对照组,以上实验各组均由培训过同一医师进行不同超声频率操作.对照组由没有培训过的医师进行超声洁治.然后以扫描电镜观察.同时,选择临床200例,随机分为两组:100例为临床实验组(下简称实验组),由专门培训的医师进行超声洁牙;另100例为临床对照组(下简称对照组),由未培训的医师超卢洁牙,半年随访临床观察.结果 从离体牙和临床的观察结果可以确定,超声输出频率最佳为4～5 MHz,手的压力为0.049035～0.09807 N,超声工作头与牙齿弧面的切面相一致的方向,成角小于20°,不能在牙面某一点上往来逗留过久,才能最大限度地降低牙面损害程度,另外超声洁牙后最好抛光.结论 超声洁牙省时、省力,但要注意使用正确的输出频率,正确的操作方法,才能做到既清除牙结石、牙垢及色素,又不损害牙体组织.

abstractsObjective To explore the best operation and power option in ultrasonic dental cleaning without damaging the teeth. Methods Twenty-five unorganized teeth were used in this study,which were divided into three groups of A,B and D,and the normal one was as control.Each group of 8 teeth was cleaned with different power and technique,and then observed under scannig electron microscope.Meanwhile,200 cases of patients,100 as the experimental group and other 100 as control,were selected to clean the teeth by well-trained dentists.In half a year they were followed up and analysed.Results The findings of treatment of unorganized teeth in vitro and 200 cases of patients,the best ultrasonic export power was 4～5 MHz.and the preasure from the hands ranged from 5 to 10 grams.The parallel direction of the transverse section and the ultrasonic probe formed an angle of 20 degrees.Minimum damage to the teeth was acheived if the working point of ultrasonic probe on the teeth swept fast and in addition the polish after the cleaning was suggested.Conclusions Ultrasonic tooth cleaning saves time and energy.The correct power export and techniques guarentee thorough cleaning of the concretion and pigmentation on the teeth,leaving the teeth intact.