he differences in the method and area of observation from other studies including the use of CBCT for the present study. The presence of more voids with lentulospirals could be due to entrapment of air bubbles during mixing of the powder with liquid, need of repeated removal and reinsertion of the instrument in the canal during the filling procedure.

Insulin syringe showed the poorest POV or less postobturated volume with a statistical significant difference compared to the other three techniques used in the present study. In case of insulin syringe, the hub being small and slender provided easy access to the pulpal orifice within the pulp chamber though the needle is not flexible which provided an intracanal reach only till the middle one third of canals, thereby causing less approach or fill of the material to the apical third of the canal and comparatively more voids in that area. Lentulospirals are more flexible thereby resulting in the complete fill of the root canals and lesser number of voids particulary in the apical third of the canal. However, in the study conducted by Nagar P et al. there was no significant difference found between the insulin syringe and hand held reamer technique when depth of fill and voids were compared radiographically.4 No studies are available where insulin syringe was compared with other filling techniques.

It would appear that the two syringes used in the present study i.e. endodontic pressure syringe and insulin syringe should have shown the similar results as both are based on the plunger system, but under the conditions of this study this was not found to be true. Though the pressure exerted by the two plunger systems was not measured for the present study, the statistically highly significant higher values of the postobturated volumes and POV of canals for the endodontic pressure syringe compared to insulin syringe, could be attributed to the obvious higher pressure generated by the plunger system of the endodontic pressure syringe than that of the insulin syringe. The ZOE mixtures used and recommended for the two syringes was thicker (0.275 ml/gm) for the endodontic pressure syringe and thinner (0.40 ml/gm) for insulin syringe. The greater pressure was required to push thicker material by the endodontic pressure syringe however; lesser force was required by the insulin syringe. In the present study insulin syringe did not exerted enough pressure to deliver even its thinner mix effectively and efficiently. This was in consistent with the findings of Aylard et.al. Therefore, it is suggested from the findings of this study that the plunger system of endodontic pressure syringe is much better in providing far greater pressure required to release the thicker mix of ZOE recommended by the manufacturers. Also comparatively flexible and thin needle of endodontic pressure syringe provided a homogenous fill with lesser number of voids in the canals of primary molars compared to the non flexible or rigid needle of the insulin syringe. The flexibility of the needle of the endodontic pressure syringe allowed it to bend simulating the curvature of the root canals of posterior primary teeth which adds to its advantage of filling the canals of primary molars particularly those with curved root canals, more efficiently and eff