常用手持根管扩大器械根管成形作用的研究

A study on the shape of prepared canal of commonly used hand endodontic instruments

用计算机图象处理方法对三种常用手持根管扩大器械包括Ｋ型扩大针、Ｋ型锉和Ｈ型锉扩大直或轻度弯曲（＜２０°）的离体单根牙后，离根尖孔３ｍｍ（根尖段）、６ｍｍ（根中段）、９ｍｍ（根颈段）的根管形态变化和根管偏移情况，结果表明：不同水平近远中向或唇舌向根管偏移无显著性差异，各组根管形态变化亦无显著性差异。另外，对重度弯曲（２５～３０°）的人工根管的根尖偏移观察表明，Ｈ锉组根尖偏移最明显，Ｋ型扩大针组最小。文中还就如何合理。

Straight or slightly curved single root canals of teeth (<20 degree) were instrumentated with three commonly used hand endodontic instruments,which included K reamer,K file and H file.The shape of prepared canal and root canal deviation at three levels were measured by computerized digital image processing program.The results demostrated that any significant differences were not found on root canal deviation in either labio lingual or mesio distal direction at each level,and that the shape of prepared canal was not different significantly.Apical transportation of the severely curved artificial root canals(25￣30 degree) showed that H file was the most severe,K reamer was the least.It is suggested in this article how we select endodontic instruments rationally and effectively.