Introduction: Accurate working length determination is a crucial factor that influences the outcome of root canal therapy. Root canal length determination is commonly performed using radiographic methods or apex locator. Aim: Determination of accuracy of electronic apex locator in the function of different employment protocols in vital and non vital teeth. Methodology: 20 patients are selected for root canal treatment. The patients are divided into 2 groups based on vital and non vital teeth. Working length determination is done by using an apex locator. The accuracy of working length determined is confirmed using digital radiography. The tooth to be treated is anaesthetised and isolated with rubber dam. Access opening is done and a 10k file is used for determining the working length using an electronic apex locator. As the file progress in, the reading is noted. Two employment protocols are used: 1. File stops at the apex and coming back to 0.5. 2. File goes beyond zero and coming back to 0.5. Result: There is no statistical significant difference between the two protocols regardless of the conditions used. Protocol 2 showed favourable results when compared with protocol 1