４只猴的６４个牙，造成实验性尖周炎后，随机分２组进行超声或手持器械预备极管。分别于治疗后３、６、９、１２个月将猴处死，每个牙根经根尖孔制６μｍ厚的牙颌组织切片，１式３份，经不同染色显示尖周的炎症状况和根管系统内细菌的存在状况，结果表明，不论哪一种方法都不能彻底去除极管系统内的细菌和牙髓组织；所有切片均显示不同程度的尖周炎症。 Four monkeys 64 teeth, resulting in experimental pericoronitis, were randomly divided into two groups for ultrasonic or hand-held device preparation. The monkeys were sacrificed at 3, 6, 9, and 12 months after treatment, respectively, and 6 μm thick dentinal and molar teeth were made in each tooth root through the apical foramen. The specimens were stained by different stains to show the periapical inflammatory conditions and root canal The presence of bacteria in the system showed that either method did not completely remove bacteria and pulp tissue from the tube system; all sections showed varying degrees of periapical inflammation.