Characterization of Ca3SiO5/CaCl2 composite cement for dental application

Objectives The purpose of this study was to investigate the effect of CaCl2 on the setting time, pH values and compressive strength of tricalcium silicate, and the in vitro bioactivity and compatibility of Ca3SiO5/CaCl2 composite paste was also studied to explore the possibility for using as a root canal filling material. Methods Composite cements were obtained by mixing Ca3SiO5 and different amounts of CaCl2 (0, 5%, 10% and 15%) with deionized water as liquid phase. The composite cement and pure tricalcium silicate were compared for setting time, pH value, compressive strength, in vitro bioactivity and compatibility. Results With the addition of CaCl2 from 0% to 15%, the initial setting time and final setting time decreased obviously from 90 to 50 min and from 180 to 90 min, respectively. The compressive strength of the Ca3SiO5/CaCl2 composite cement after setting for 7 days increased obviously from 5.28 to 23.46 MPa when the content of CaCl2 increased from 0% to 10%. Furthermore, the paste with up to 15% of CaCl2 showed good ability to induce the formation of hydroxyapatite (HA), and the dissolution extracts of the Ca3SiO5/CaCl2 composite paste also have a stimulatory effect on L929 cell proliferation in a certain concentration range. Significance The results indicated that the Ca3SiO5/CaCl2 composite cement had good self-setting properties, bioactivity and compatibility, and may be used as a novel root canal filling material.