自制口内平行备牙仪对提高牙体预备质量的研究

Study on the Parallel Tooth Preparing Instrument to Improve the Quality of Tooth Preparation

目的:研制口内平行备牙仪,用提高牙体预备质量。方法:根据Parallel-A-Prep的原理,制成由金属托盘、可折叠的延伸臂、适配器、观测针组成的新型口内平行备牙仪。在模型上对64颗后牙进行备制,测量倒凹数、倒凹坡度及轴面会聚度并与传统的目测法进行比较。结果:用新型口内平行备牙仪备牙后,倒凹数和内聚度远远小于目测法备牙法,大大提高了固定桥基牙的共同就位道。结论:口内平行备牙仪可提高固定桥基牙的共同就位道,大大减少倒凹的发生及内聚角的度数,明显提高牙体预备质量。

Objective：To develop aparallel tooth preparing instrument to improve the quality of tooth preparation.Methods：The newly device of parallel tooth preparation was made of metal tray,collapsible spread arm,adapter,and observation pin according to the principle of Parallel-A-Prep.64posterior teeth,prepared on models were measured in order to compare the quantity of undercut,the gradient of undercuts and angles of convergence between conventional visual preparation and this device preparation.Results：The quantity of undercuts and angle of convergence of study group were significantly less than that of control group.Common insertion paths were achieved easier in study group.Conclusion：The newly parallel tooth preparing instrument can improve the common insert path and reduce the quantity of undercut and the angle of convergence of abutment teeth,therefore improve the quality of tooth preparation.