Compressive strength evaluation and phase analysis of pulp capping materials based on carbonate apatite-SCPC using different concentration of SCPC and calcium hydroxide

The mechanical strength of pulp capping material based on carbonate apatite and silica calcium-phosphate composite (CO₃Ap-SCPC) is one of the key factors for the success of the material in protecting the vitality of the pulp during the formation of apatite and dentin reparative. Modifying the material in the powder phase was known to increase the mechanical strength. The purpose of this study was to determine whether the addition of SCPC and calcium hydroxide in pulp capping materials based on CO₃Ap-SCPC would affect the compressive strength of this pulp capping material. In this study, three cement groups were used, each group consisted of dicalcium phosphate anhydrous and vaterite which added by SCPC concentration 0%, 5% and 10% and calcium hydroxide concentration 0%, 5% and 10%, respectively. All groups were tested by a compressive strength test and X-Ray diffraction (XRD) for phase analysis. The mean value of compressive strength with addition of 0% SCPC and 10% Ca(OH)₂ was 16.54 ± 1.35 MPa, addition of 5% SCPC and 5% Ca(OH)₂ was 18.55 ± 2.81 MPa, addition of 10% SCPC and 0% Ca(OH)₂ was 9.22 ± 1.21 MPa. The addition of SCPC and Ca(OH)₂ show statistically significant in compressive strength (p<0.05). The XRD analysis of the highest compressive strength revealed that the apatite crystal was successfully formed. It can be concluded that incorporated specific amount of SCPC and Ca(OH)₂ could improve the mechanical strength and the apatite formation of the CO₃Ap-SCPC pulp capping material.