The aim of the present study will be to clinically evaluate the post operative pain during root canal preparation , with three different methods of working length preparation. 

Suitable number of patients will be selected for this in-vivo study . Single rooted tooth will be taken into consideration for this study . Healthy young patients having irrerversible pulpitis with  tooth positive to a percussion test , negative to palpation test  and without any periapical lesion or any systemic disease will be included in this study

Patients which will be excluded from the study according to the following criteria: those with systemic diseases, swelling, sinus tract, or preoperative palpation pain , those having bruxism or clenching , a severely damaged tooth, severe periodontal disease in related tooth or resorption in related tooth , having previously undergone root canal treatment in related tooth.

A digital radiograph will be used to confirm the presence of single root for the tooth to be operated on . Preoperative pulpal diagnosis will be performed by both cold test and Electric pulp test .Periapical diagnosis will be performed by periapical radiographs and percussion and palpation tests  .

Patients will be randomly distributed into 3 experimental groups viz. Radiographic group, Electronic apex locator group and Simultaneous Prepared Group; with equal number of  patients  in each group. After the root canal preparations , patient will be evaluated for post operative pain after 24hrs ,48 hrs & 72 hrs respectively , keeping in mind no anaelgesics were given post-operatively before pain evaluation . Patient will respond for pain after percussion on a designed visual analogue scale for pain.