In vitro evaluation of the accuracy of ProPex II, Raypex 6 and iPex II electronic apex locators in primary molar teeth

Background: Electronic apex locators (EALs) have become popular to measure the working length in permanent teeth in recent years, and they have helped for estimation of the working length more accurate. Objective: The purpose of this study is to evaluate the accuracy of ProPex II, Raypex 6 and iPex II EALs in primary molar teeth. Materials and Methods: Fifteen mandibular primary second molar teeth with 48 root canals were measured by all EALs. The direct length (DL) of the root canals was measured visually. The differences between DL and electronic working length (EWL) measurements of each device were calculated. Statistically analysis was performed using Student′s t-test, and the significance level was at 5%. Results: For the measurements of ProPex II, the reliability of ±0.5 mm was determined in 77% of all root canals. For Raypex 6, the same result (77%) was observed when the accuracy was also accepted as ±0.5 mm. On the other hand, the result was found as 79% in the measurements of iPex II when the same accuracy limit (±0.5 mm) was considered. When the accuracy limit was ±1 mm, the determined values were 96% for ProPex II and Raypex 6 and 94% for iPex II. There was no significant difference between each EAL group (P > 0.05). Conclusion: The ProPex II, Raypex 6, and iPex II EALs showed similar results and all tested EALs were able to determine the working length in primary molar teeth accurately.