Clinical Evaluation of Electronic Apex Locator in Primary Teeth

MATERIALS & METHODS: The pulp tissue was removed from 41 incisors and molars. After irrigation the root canals (n= 105) with (NaOCl 1%),the length was determined clinically with each electronic device prior to extraction.The real length(RL) was recorded after extraction, and compared with measurements of each electronic device. RESULTS:Paired samples T test was performed at significance level:95%(P≤0.05); there was a significant difference in length variation(LV) between the tow devices; in ZX:(x=-0.29 +/- 1.43 mm) with a tendency to estimate the root canal length just short of the apex, while in AFA the LV was higher(x = +0.46 +/- 1.63 mm)with a tendency to overestimate the apex. The resorption's degrees(Res) were:38.1% (Res1:less than1/4 of the root), 42.9%(Res2:1/4 of the root), 19%(Res3:1/2 of the root).ANOVA and Bonferroni tests showed a significant difference in LV between the Res1 and Res2 in AFA; but measurements of ZX were not affected by resorption's degree.The results of tow devices were not influenced by root canal type and pulp vitality.

CONCLUSION: The accuracy of ZX is higher than AFA which has a tendency to overestimate the apex; therefore it is better to use the bias switch in AFA to stop before the apex foramen The accuracy of AFA is affected by the half root resorption or less; that is may be explained by the sample's destruction ,or the apex foramen shape or size,while ZX is not affected.