作者用超声波和手工对３８颗无保留价值的患牙分别行龈下刮治，离体下用体视镜及图象分析仪观察并计算根面残留菌斑及牙石占观察面积的比率。结果表明无论在浅袋区或深袋区，两种方法清除牙石及菌斑效果相同。超微结构显示超声波洁治组根面出现牙骨质部分或全层剥脱，手工刮治组部分根面出现划痕，两种方法均不能完全清除深袋区牙石和菌斑。 The authors treated 38 intact teeth with subgingival scaling by ultrasound and manual, respectively, and observed and calculated the ratios of residual plaque and calculus to the observed area with a stereo microscope and an image analyzer. The results show that both in shallow bag area or deep bag area, the two methods to remove calculus and plaque effect the same. The ultrastructure showed that the root surface of ultrasonic cleaning group had partial or full cementum exfoliation, some of the root surface scratched by manual scraping group, and both methods could not completely remove the deep pocket calculus and plaque.