Context: Pulpectomy is recommended for primary teeth when both the coronal and radicular pulp tissues are irreversibly damaged. Biomechanical preparation of root canals is essential for the success of endodontic treatment. Achieving the optimal length during obturation while minimizing voids and ensuring a hermetic seal is crucial for the success of pulpectomy procedures. Aims: The aim of this in vitro study is to compare the root canal obturation quality among Lentulo Spiral, Pastinject, and Dispo Van syringe in primary teeth using cone-beam computed tomography (CBCT) scanning. Settings and design: The selected extracted primary teeth were from the age-group of 4–7 years. Teeth indicated for pulpectomy with at least two-thirds of the total root length present were included. The study was conducted over a duration of 6 months. Methods and materials: The study examined 60 primary tooth root canals, divided into three groups. Endoflas was used for obturation with Lentulo Spiral, Pastinject, and Dispo Van syringe. Postoperative CBCT was used to assess the presence of voids. Statistical analysis used: The values were analyzed for the success rate of obturation using an independent t-test with MedCalc for Windows. Results: In this study, three different filling techniques were evaluated and compared based on the presence of voids in the canals. Pastinject exhibited superior performance with the fewest voids, followed by the Lentulo Spiral and Dispo Van syringe. Conclusion: The findings indicated that the most effective technique for obturating primary teeth was the Pastinject method.