Although the available scientific evidence base is short and at considerable risk of bias , it is still possible to conclude that the apical locator reduces the patient radiation exposure and also that the electronic method may perform better on the working length determination .
INTRODUCTION Apical constriction has been proposed as the most appropriate apical limit for the endodontic working length .
Despite being the most used , some limitations are attributed to the radiographic method of working length determination .
It lacks precision because it is based on the average position of the apical constriction .
The electronic apex locators have been presented as an alternative to the odontometry performed by radiography .
These devices detect the transition of the pulp to the periodontal tissue , which is anatomically very close to the apical constriction and may perform with improved accuracy .
An in vivo evaluation of the ENDEX and RCM Mark II electronic apex locators in root canals with different contents.
The accuracy of many apex locators is affected by electrolytes including sodium hypochlorite . According to the manufacturer a new device , the ENDEX , overcomes this problem . The purpose of this study was to assess the accuracy of the ENDEX in comparison with a traditional device , the RCM Mark II . The lengths of 61 canals with various contents ( vital pulp , necrotic pulp , pus/exu date , sodium hypochlorite , and water ) were determined in vivo . Files were cemented within the canals at lengths determined by the ENDEX . The teeth were then radiographed and extracted , and the distance between the file tip and apical foramen was recorded . Derived readings for the RCM Mark II were compared with the actual ENDEX reading and corresponding radiograph . The results indicated that most of the file tips that were at the radiographic apex actually extended through the apical foramen , and canal content had a varying effect on each device . The overall accuracy of the ENDEX  ( 71.7 % ) was higher than that of the RCM Mark II ( 43.5 % ) within 0.5 mm of the apical foramen . The ENDEX , unlike the RCM Mark II , proved accurate in the presence of sodium hypochlorite
Although the available scientific evidence base is short and at considerable risk of bias , it is still possible to conclude that the apical locator reduces the patient radiation exposure and also that the electronic method may perform better on the working length determination .
INTRODUCTION Apical constriction has been proposed as the most appropriate apical limit for the endodontic working length .
Despite being the most used , some limitations are attributed to the radiographic method of working length determination .
It lacks precision because it is based on the average position of the apical constriction .
The electronic apex locators have been presented as an alternative to the odontometry performed by radiography .
These devices detect the transition of the pulp to the periodontal tissue , which is anatomically very close to the apical constriction and may perform with improved accuracy .