超声波后牙根尖倒预备牙体切割量的定量研究

目的定量研究超声波与传统慢速手机根尖倒预备牙体组织切割量的差异。方法 32例附有颌骨和牙周组织,含两个主根管的下颌第一磨牙近中根,随机分成2组,分别采用两种处理方式进行倒预备：（1）超声波组：超声波配金刚砂尖Berutti与镍钛尖RE2;（2）慢速手机组：慢速手机配2号圆钻。显微成像系统和数据分析系统分别测量预备前、后根切面的相关参数并进行计算分析,定量比较两种倒预备技术牙体组织切割量的差异。结果超声波根尖倒预备切割的牙体组织量明显少于慢速手机（P〈0.001）。结论超声波倒预备技术能更有效地保护牙根尖硬组织,保持牙根的强度。

The Cutting Volume of Ultrasonic Posterior Teeth Root-end Preparation:A Quantitative Study

Objective To compare quantitatively the cutting volume of posterior teeth root-end preparation between ultrasonic retrotips and traditional slow-speed handpiece.Methods 32 mesial roots of the mandibular first molars with two canals,mature root apices,and periodontal tissue were assigned randomly to 2 groups of 16 each.The root-end preparations were made respectively using ultrasonic diamond tip Berutti and NiTi tip RE2 and slow-speed handpiece with No.2 round bur.Image processing and analysis system were used to measure the preoperative and postoperative parameters for further evaluating the difference between the two groups.Results The cutting volume of ultrasonic instruments was significantly less than that of slow-speed handpiece group（P0.001）.Conclusion Ultrasonic instrument is feasible in the posterior teeth root-end preparation.