Methods: As solid phases determined by XRD, different C3A content powder were proved, and three different C3S /C3A ratio fabricated with sol-gel technique ( 90/10, 70/30, 50/50) as experimental groups, and WMTA (ProRoot, Dentsply / Tulsa Dental, Tulsa, OK, USA) as a comparable group. The physical properties such as setting time, micro-hardness were measured by Gillmore pin and Micro-hardness tester (SHIMADADZU, HMV-2, Japan). The morphology and phase composition of hydration products were observed by SEM and EDS. The MTT assay was used to evaluate the cytotoxicity and ALP assay and Alizarin test were used to observe mineralization. Data was analyzed by one-way analysis of variance and post-hoc test with a significance of P<0.05.
Results: The initial setting time of 70/30, 50/50 groups were between 10-25 minutes, which were significantly lower than WMTA (165 minutes) and 90/10 group(81 minutes). The micro-hardness of 50/50 and 70/30 were also significantly higher than WMTA in the first day (p<0.05). By SEM and EDS, the hydration products were observed the calcium hydrogen phosphate in all groups. The biocompatibility of all groups were as good as the negative control except 50/50 with mild cytotoxicity. The mineralization observation showed that all groups could induce hard tissue formation.
Conclusions: When the proportion of C3A increased to 30% to 50% in calcium silicate ceramics material, the setting time and micro-hardness were significantly improved. Moreover, the 90/10 group has optimal biocompatibility, and mineralization ability.