eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2015-10-25 8 October Spl Edition 335 339 10.13005/bpj/700 3503 article J. Prabhakar 1 Alagarsamy Venkatesh 2 Gold Pearlin Mary 2 Department of Conservative Dentistry and Endodontics, Tagore Dental College and Hospital, Chennai, India Department of Conservative Dentistry, Sree Balaji Dental College and Hospital, Bharath University, Pallikaranai, Chennai-600100 Accurate working length determination is a prerequisite for successful root canal treatment, reducing the chance of insufficient cleaning of the canal or of damaging the periapical tissues from over instrumentation. The use of an electronic apex locator has improved the accuracy of the working length measurement in clinical endodontics. The purpose of this in-vivo study was to compare the accuracy of three different Electronic Apex Locator (EALs). Twelve    human  mandibular   premolar to be extracted for orthodontic treatment were selected. Teeth were divided into three groups Group 1   (n = 4) (IPex, NSK   NAKANISHIINC, Tochigi, Japan) Group 2  (  n =4) (Mini Apex Locator ,Sybron Endo, Glendora,CA, USA) Group 3 ( n=4)(IROOT S,S-Denti,Korea).After determining the working length the No 10 Kfile was cut at the reference point and sealed in position using Glass Ionomer cement. Tooth is extracted and apical 3- 5mm is exposed and photographed using SLR digital camera. The distance between file tip and minor apical diameter were measured using a calibrated measurement software. (Adobe .version 9). Raw data of 12 samples were recorded and inference was made. Within the limitation of this pilot study we are able to comment that all the Electronic Apex Locators evaluated in this  study performed to the recommended accuracy. Further study is important to statistically analyze above mentioned comment. https://biomedpharmajournal.org/vol8octoberspledition/accuracy-of-three-different-electronic-apex-locators-a-pilot-study/ Electronic Apex Locator EAL Working length