Effect of Overlying Material on BiodentineTM Setting Reaction in Primary Molar Pulpotomies

Objective: The purpose of this in vitro study was to evaluate the effect of different overlying materials, such as Intermediate Restorative Material (IRM) or resin-modified glass ionomer cement (RMGIC) on the hardness of BiodentineTM, used as a pulpotomy agent in primary teeth, as a function of its hardness 24 hours after final tooth restoration. Methods: Forty extracted primary molars were mounted in stone. The teeth were randomly selected into four groups of ten teeth each. Occlusal cavities were prepared to the furcation and pulpal debris was excavated in each sample. Group 1 was restored with BiodentineTM, IRM, and a Stainless Steel Crown (SSC). Group 2 was restored with BiodentineTM, Fuji II, and a SSC. Group 3 was restored with BiodentineTM and an SSC. Group 4 was restored with BiodentineTM only. All samples were stored in an incubator at 37C and 100% humidity. After 24 hours, samples were sectioned mesio-distally and polished. The setting reaction was measured as a function of Knoop Hardness value (HK) using Leco Microhardness Tester. Each sample was measured at three zones with a 50gf load force for 30 seconds starting at one millimeter from the BiodentineTM material interface. The data was analyzed using One-Way ANOVA and post-hoc Tukey test. Results: There was no significant statistical difference in the mean value among the four groups (p>0.05), and among the three zones. Conclusions: In this in vitro study, BiodentineTM was a suitable restorative material for primary molar pulpotomies and the overlying material showed no influence on the hardness of BiodentineTM after 24 hours.