In this study, the effect of mineral trioxide aggregate (MTA) and Biodentine on the resistance to fracture of pulpotomized primary molars was evaluated. 75 primary molars were divided into 2 control groups (positive and negative) and 3 experimental groups with 15 teeth each. No treatment was applied to the teeth in the negative control group. In the teeth in the positive control group, pulpotomy cavities were performed, but not filled. In the teeth in the experimental group, pulpotomy cavities were performed, and filled as follows. Group 3: mineral trioxide aggregate + glass ionomer cement (GIC); Group 4: Biodentine + GIC and Group 5: zinc oxide-eugenol + GIC. Final restorations in teeth in all experimental groups were completed with composite filling material. 75 teeth were then subjected to fracture resistance testing. Obtained data were analyzed statistically. Sorting by fracture resistance; Group1 > Group 4 > Group 3 = Group 5 > Group 2 ( p < 0.05). Restorable fracture type was predominant in experimental groups ( p < 0.05). The use of Biodentine in teeth undergoing pulpotomy in primary teeth can be preferred as a suitable base material to increase resistance to fracture.