Comparative investigation of the effect of calcium silicate based materials on microhardness of dentin

The aim of this study is to design that MTA and Endosequence BC Sealer, which are calcium silicate based materials, can be realized in crown and root dentin hardness. 50 single root premolar and 50 molar teeth were collected. 2 mm thick sections were obtained with a precision cutting device from the middle three of the premolar tooth roots and molar tooth crowns. Hardness values in Knoop terms were measured and recorded by applying 300 g force to these sections for 15 s with a microhardness device. Calcium silicate based materials were applied to the inner parts of the canal in root sections and to the center of the section in crown sections. 20 sections were divided into control group. They were placed in an oven for 21 days at 37◦C and the samples were moistened every 3 days. The hardness measurements of the samples taken out of the oven at the end of 21 days were repeated. Scanning electron microscope (SEM) image was taken by selecting one slice from each group. The difference between previous and subsequent hardness changes was evaluated using the t test and the Wilcoxon signed rank test. A significant difference was found between groups with multiple pair comparisons using one-way analysis of variance (ANOVA) and Scheffe post hoc test. Endosequence BC Sealer and MTA decreased dentin hardness in intracanal application and on the dentin surface. The change percentages of the experimental groups were statistically significantly higher than the control groups. The hardness values on the dentin surface decreased more than in the canal application. MTA and Endosequence BC Sealer calcium silicate based materials decrease dentin hardness.