Effects of different irrigation solutions on the accuracy of electronic apex locators in curved and straight root canals

Aim: To evaluate the effects of different irrigation solutions on the accuracy of 4 different electronic apex locators (Propex II, Propex-Pixi, Dentaport ZX, DTE Dypex V) (EALs) in curved and straight root canals.

Methods: A total of 20 extracted human teeth; 10 maxillary incisors with straight root canals and 10 mandibular molars with curved root canals, of which the curvature angles were between 30-50 degrees were selected. A #10 K-type file was advanced under a stereomicroscope at X15 magnification until the file was seen apically and the measured value was recorded as actual length (AL). Then, electronic length (EL) was determined using the selected EALs in different irrigation solutions. Group 1 was the control group. 1% NaOCl, 2.5% NaOCl, 5% NaOCl, 2% CHX, 17% EDTA and EDTA gel was used for groups 2-7, respectively. After each measurement, the roots were washed with 5 mL of distilled water and dried with a paper point before the same teeth were used in the next group. The difference was calculated by subtracting each tooth’s AL from EL.

Results: When EALs accuracy was compared, there was a significant difference for Propex-Pixi and DTE Dypex V. When EALs’ accuracy was compared in presence of different irrigation solutions, there was a significant difference in the Control group and Group 5.

Conclusions: All EALs performed more successfully in straight canals than in curved canals. Electronic measurements of molars with curved root canals were affected in the presence of CHX and when the root canals were dry.