牙髓状态对Root ZX根尖电测仪准确性的影响

The Influence of Pulp Status on the Accuracy of Root ZX Electronic Apex Locator

目的:评价牙髓状态对Root ZX根尖电测仪测定根管长度准确性的影响。方法:选择根尖发育完全,因正畸、牙周疾病及义齿修复需拔除的单根牙,利用活力检测仪测定牙髓状态,获得活髓牙及死髓牙各31例。开髓,分别在保存牙髓及拔除牙髓后,Root ZX根尖电测仪测定根管长度,然后拔除该牙测定根管实长,比较牙髓存在前后测量长度与实际长度间的差别。结果:活髓牙牙髓存在时根管测量长度为(19.95±1.77)mm,拔髓后测量长度为(20.04±1.79)mm,拔牙后根管实际长度为(20.39±2.01)mm。死髓牙拔髓前根管测量长度为(19.72±1.77)mm,拔髓后测量长度为(19.80±1.76)mm,拔牙后根管实际长度为(20.12±1.74)mm。拔髓前/后与实际长度比较均没有显著差异(P>0.05)。以0.5 mm准确标准,活髓牙拔髓前/后准确率分别是61.29%和64.52%,死髓牙拔髓前/后准确率分别是64.52%和67.74%。拔髓前/后及活髓/死髓牙准确率均无显著差异(P>0.05)。结论:牙髓状态及牙髓存在与否对Root ZX根尖电测仪测定根管工作长度的准确性没有明显的影响。

Objective： To evaluate the influence of pulp status on the accuracy of determining root canal length by Root ZX electronic apex locator in vivo. Methods： 31 vital and 31 necrotic teeth （single canal） were obtained from patients extracted for orthodontic and periodontal reasons. The pulp vitality was evaluated by Pulp Evaluator. The teeth were anesthetized, isolated and accessed. Root canal lengths were determined by Root ZX apex locator before and after pulp removed. After extracted the teeth, accurate lengths of teeth were accessed by file to apical foramen. Accuracy was compared between vital and necrotic teeth with and without pulp. Results ： In vital teeth, the values of root length were （ 19.95 ± 1.77 ） mm and （20.04 ± 1.79） mm before/after pulp removed. In necrotic teeth, the length were （ 19.72 ± 1.77） mm and （ 19.80 ± 1. 76） mm before and after pulp removed. There was no significant difference between the lengths of vital and necrotic teeth with/without pulp （ P 〉 0.05 ）. With a tolerance level of 0.5mm, an accuracy rate of 61.29% and 64.52% were recorded before and after pulp removed in vital teeth. An accuracy rate of 64.52% and 67.74% were recorded before and after pulp removed in necrotic teeth. There was no significant difference between teeth with and without pulp and also no significant difference between vital and necrotic teeth （ P 〉 0.05）. Conclusion： The pulp status has little effect on the accuracy of woking length in Root ZX electronic apex locator.