Accuracy of electronic apex locators in primary teeth: a meta‐analysis

Aim To conduct a meta-analysis on the accuracy of electronic apex locators (EALs) in determining working length in human primary teeth. Methodology An electronic literature search was conducted using a combination of the terms ‘primary teeth’, ‘root canal length’ and ‘electronic apex locators’. Additional eligible articles were identified using a manual search. The full texts of identified articles were screened according to inclusion criteria. Results Overall, 19 studies met the inclusion criteria and were subjected to further data extraction. Meta-analysis of studies that reported mean lengths and difference in mean lengths between EAL and actual root canal length (ARCL) revealed a significant difference (P = 0.015) between the two readings whilst those studies that evaluated intraclass correlation (ICC) suggested a high correlation (P < 0.0001) between the EAL and ARCL readings. A subgroup analysis revealed that the presence of root resorption did not affect the accuracy of EALs (P = 0.567). Conclusion Electronic apex locators offer an acceptable level of accuracy in the measurement of root canal length in primary teeth.