Setting Time and Bond Strength of New CaO-SiO₂-Based Cements

Objectives: Mineral trioxide aggregate (MTA), with the tricalcium silicate as the major component, is a commercial material using in retrograde filling, perforation repair and vital pulp therapy with promising results. However, several disadvantages of MTA have been reported, such as long setting time, difficulty in handling, and arsenic elements contained. To solve the problems, we developed new and pure CaO-SiO₂-based cements (CSCs) without toxic ingredients in endodontic therapy, and further evaluated their potential using in endodontic application. Methods: Two CSCs were produced via sintering process at high temperatures called M811 and via sol-gel process called sM811. White MTA was used as a control group. The powder of each material was mixed with distilled water in a constant powder to liquid ratio (2.5/1 for CSCs and 3/1 for white MTA) to prepare specimens for tests. The setting time test was performed by following the standard of ISO6876 and the dentin bond strength was investigated using push-out bond strength test method. Results: sM811 (108±21.69 min) demonstrated a significant decrease in setting time when compared to the M811 (162.5±2.88 min) and white MTA (355±7.07 min) groups. The dentin bond strength of sM811 (11.28±4.82 MPa) was significantly higher than M811 (5.05±2.90 MPa), but significantly lower than white MTA (20.32±7.57 MPa). Conclusion: The new developed CSCs, sM811 and M811, were potential alternative endodontic repair materials since they could solidify much faster than white MTA. However, further studies are needed to improve their dentin bond strength .