4种液体对电子根尖定位仪测量准确性的影响

目的:研究4种液体对Raypex 5、TRRY 2种电子根尖定位仪(electronic apex locator,EAL)测量准确性的影响.方法:采用1%琼脂凝胶和单根管离体牙构建EAL体外评价模型,使用2种EAL,分别在0.9%NaCl、5.25%NaOCl、人血和17?TA的环境下,对47颗单直根管离体牙进行根管长度测量,记录测量值(experimental measurements,EM)、测量值和理论实际值(ideal actual measurements,IAM)之间的差值(IF值).测量结果采用SPSS10.0软件包进行配对t检验.结果:以IF值±0.5mm为衡量标准,Raypex 5在根管中充满0.9%NaCl、5.25%NaOCl、人血和17?TA 4种液体时的准确性分别为91.5%、91.5%、100%和97.8%,TRRY 分别为95.7%、93.5%、93.5%和84.8%.当根管内充满0.9%NaCl和5.25%NaOCl时,2种EAL的IF值无显著差异:当根管内充满人血和17?TA时,2种EAL的IF值有显著差异(P<0.05).结论:根管中存在不同液体时,Raypex 5与TRRY 能够在本实验条件下较为准确地测量离体牙的根管长度.

Effect of four different solutions on the accuracy of electronic apex locators

PURPOSE: To investigate four different solutions on the accuracy of two electronic apex locators (EAL) in vitro. METHODS: 1% agar and extracted single-canaled tooth were used to mimic the situation in vivo. Forty-seven teeth were used. Two kinds of electronic apex locator, Raypex 5 and TRRY , were applied to determine the length of the canals being flooded with four different solutions. Experimental measurements and the distances(IF value) between experimental and ideal actual measurements under the same measurement environment were recorded. Paired sample t test were applied to analyze the results by using SPSS10.0 software package. RESULTS: While the canals were flooded with 0.9% NaCl, 5.25% NaOCl, human blood and 17%EDTA, the ratios of the distance within limits of +/-0.5mm were 91.5%, 91.5%, 100% and 97.8% for Raypex 5 and 95.7%, 93.5%, 93.5% and 84.8% for TRRY , respectively. There was a significant difference in accuracy between two EALs regarding blood and 17% EDTA (P<0.05). CONCLUSIONS: Both Raypex 5 and TRRY can measure root canal length accurately despite the influence of solutions under this experimental environment.