Electronic & Radiographic Endodontic Working Length Measurements of Human Posterior Teeth Clinical Comparative Study

Introduction: Successful root canal therapy depends upon accurate measuring of  root canal Length (RCL) prior to biomechanical instrumentation and hermetic obturation. Objectives:  the aim of this study was to evaluate the consistency of second generation electronic apex locator (SGEAL)  measurement of (RCL) compared to conventional radiographic method (CRM)of  (RCL) and to evaluate if there is  any effect of tooth  vitality on the accuracy of the (SGEAL).  Methods: Twenty four multirooted teeth with 55 canals were  included,  eleven canals were excluded due to radiographic  technical errors .SGEAL was  used to measure the(RCL) from constant reference point on occlusal surface to apical constriction following the manufacturer instructions. Ingle's method was used to measure the radiographic (RCL) using the same reference point. The readings of the (SGEAL) were compared to the readings that obtained using the (CRM). Results:  the result of this study revealed that the (SGEAL) was less accurate in determining the(RCL) compared to (CRM)(p value 0.198), the(SGEAL) readings were consistent(± 0.5mm) with    (CRM) readings in 50% of the cases, according to type and location of teeth upper molars showed significant difference (p:0.017). According to vitality, the vital teeth 50% (14canals) showed an equal readings, in the  non-vital teeth equal readings  were recorded in 43.7 %(7) canals. Conclusion:  Within the limitations of this study it is concluded that the use of (SGEAL) still can not replace the (CRM) in determination of the  (RCL) in posterior teeth .More studies were recommended using recent  types   apex locators, comparing them with actual root canal length.