3种往复旋转单支镍钛器械预备人下颌标本切牙根管后牙根微裂形成的比较

摘要

目的:采用显微CT (Micro CT)观察3种往复旋转单支镍钛器械预备人下颌标本切牙根管后牙根微裂的形成情况,为临床上往复旋转单支镍钛器械的选择提供依据.方法:选取15个人下颌标本,共60颗单根下颌切牙,且均无牙根微裂,根据根管预备中所用镍钛器械的不同随机分为4组,每组15颗牙齿,以ProTaper Universal组为对照组,以Wave One组、Reciproc组和One File组为实验组.按厂家提供的使用说明书预备根管,Wave One镍钛锉、Reciproc镍钛锉和One File镍钛锉预备根管至25#,ProTaper Universal镍钛锉预备根管至F2.根管预备后每组牙齿分别用Micro CT进行扫描,分析牙根微裂的发生情况.结果:与ProTaper Universal组比较,Wave One组、Reciproc组和One File组牙根微裂发生率明显降低(P＜0.05);Wave One组、Reciproc组和One File组牙根微裂发生率组间比较差异无统计学意义(P＞0.05).各组下颌切牙中牙根微裂纹均在根尖1/3处最为常见,其次为根中1/3.结论:根管预备过程易引起牙根微裂,需要重视镍钛器械的选择,3种往复旋转镍钛器械Wave One、Reciproc和One File根管预备后牙根微裂形成少,能降低根管治疗后牙根折裂风险.%Objective:To observe the development of dentinal microcracks after root canal preparation with there kinds of reciprocating nickel-titaninm instruments using an in situ cadaver model by means of micro-computed tomography (Micro CT),and to provide the reference for their clinical application.Methods:A total of 15 mandible bone specimens having at least the anterior teeth (n=60) with single root were selected and there was no dentina microcrack,then they were randomly divided into 4 groups (n=15) according to the preparation protocol:Wave One,Reciproc,One File and ProTaper Universal groups,and ProTaper Universal was used as control group.The root canals were prepared up to 25 # instruments in Wave One,Reciproc and One File groups and F2 instruments in ProTaper Universal groups.After the preparation procedures,the specimens were scanned by Micro CT again,and the number of dentinal microcracks were investigated and analyzed statistically.Results:Compared with ProTaper Universal group,the incidence rates in Wave One,Reciproc and One File groups were significantly reduced (P＜0.05).There were no statistical differences in the incidence rates of dentinal microcracks between Wave One,Reciproc and One File groups (P＞0.05).Conclusion:Root canal preparation can cause the dentinal microcracks,so it is important to choose the types of instruments.Root canals prepared with Reciproc,Wave One and One File produce less dentinal microcracks,which can decrease the risk of vertical root fracture.