Lateral Canals – Incidence and Effect of Instrumentation Method on Access

Objective: The purpose of this study was to examine the incidence of lateral/accessory canals in roots of extracted teeth and to evaluate the effect of two endodontic instrumentation techniques on access to these areas during obturation. Methods: 216 extracted single-rooted human teeth were randomly placed into one of two groups. The first group received hand instrumentation while the second group received rotary NiTi instrumentation (GT/Profile). Teeth in each group received the same irrigation, sealer and obturation (System B/Obtura) techniques. Teeth were cleared and examined under a steromicroscope at 70 X magnification for detection of lateral/ accessory canals and for evidence of filling these canals. Results were analyzed using Fishers exact test. Results: Out of 216 teeth examined, 103 lateral canals were found in 74 teeth. Within the hand instrumentation group, 111 teeth were examined and 46 lateral canals were identified in 35 teeth. A total of 20 of the lateral canals in 19 teeth were filled (43.5%). Within the rotary instrumentation group, 105 teeth were examined. 57 lateral canals were identified within 39 teeth with a total of 20 lateral canals filled in18 teeth (35.1%). Fishers exact test indicated that instrumentation method did not significantly affect the filling of lateral canals (p=0.42). Conclusion: The incidence of lateral canals in non-molar teeth was 34.3%. Rotary instrumentation did not significantly affect the filling of lateral canals, compared to hand instrumentation.