Introduction: Pulpectomy helps in preserving a pulpally involved primary tooth by extirpating the diseased pulp associated with microorganism and debris from the canal and obturating with an antibacterial resorbable filling material Aim: To evaluate and compare the obturation quality interms of underfilling,optimal filling, over fillings, and voids in single rooted teeth amongst the 4 different obturation techniques using cone beam computed tomography( C.B.C.T.) Method:40 freshly extracted single rooted teeth were collected and where arranged on U shaped arch ,each arch contained 10 teeth each and 4 groups and obturated with lentulospiral technique, local anaesthetic syringe, endodontic pressure syringe, pastinject technique.The assessment of obturation technique was done using CBCT. For evaluating quality of obturation and voids in the obturated canals, based on the following criteria given by Coll and Sadrian (1996)was used for CBCT and checked for Under filling ,Optimal filling ,Over filling and Voids. Results: Pastinject showed 90% of optimal filled canals and minimum void. Endodontic pressure syringe showed minimum number of optimum filled canals(20%) Conclusion: Pastinject technique of obturation proved to be the best in terms of optimal filling and less number of voids.