BackgroundUltimate goal of BMP is to extirpate the pulp tissue completely, microorganisms, debris & shaping the canal which preserves the original course of the canal to receive an obturating material. Due to various morphological challenges present in deciduous root canal, there is high demand of an improved quality & design of file system with less working length to prevent undesirable complication & reduce treatment time. Aim: To evaluate & inter-compare the dentin thickness and instrumentation time in root dentin of deciduous teeth after BMP in Hand, Rotary & Reciprocation motion with single-file systems.Material and Methods60 extracted primary single rooted teeth with un-resorbed roots were included in the study. Teeth were divided into three groups consisting of 20 teeth in each group. In Group-1 Root canal preparation was done with pediatric Hand files, In Group-2 with pediatric Single-file system in rotary motion and in Group-3 with pediatric Single-file system in reciprocating motion. Teeth were scanned before & after preparation with CBCT. Segments were analyzed for dentin thickness at 3mm,5mm and 7mm respectively. Instrumentation time was recorded by an assistant.ResultsMean instrumentation time of Rotary was least as compared to Reciprocation & Hand respectively, instrumentation time taken by hand filing was significantly higher. Reciprocating filing helps in better dentin debridement at apical and the middle third and no difference was found at the coronal third among all three groups.ConclusionsReciprocating filing helps in better dentin debridement and rotary instrumentation requires least time for canal preparation.Key words:Hand Files, Rotary Files, Reciprocating motion, CBCT.