Evaluation of Tricalcium Silicate-Based Cements Associated With Different Radiopacifiers

Objectives: Tricalcium silicate-based cements (TCS) is used as the main component in the formulation of new biomaterials due its biocompatibility and bioactivity. Bioactive cements have been developed using tricalcium silicate associated with different radiopacifiers. MTA Repair HP (MTA HP) is a cement similar to MTA, which has CaWO₄ as radiopacifier in addition to a plasticizing agent in the liquid. The aim of this study was to evaluate physicochemical, biological, and antimicrobial properties of TCS associated with the radiopacifiers zirconium oxide (ZrO₂), calcium tungstate (CaWO₄) or niobium oxide (Nb₂O₅), compared with MTA HP.
Methods: The study performed physicochemical tests: setting time, radiopacity, pH and solubility, besides in vitro assays: cytotoxicity (MTT and Neutral Red - NR), and cellular bioactivity: alkaline phosphatase activity (ALP) and alizarin red (ARS). To evaluate the antibacterial activity, direct contact test was performed on Enterococcus faecalis in planktonic cells. For physicochemical and ARS tests, the data were submitted to ANOVA and Tukey; for evaluation of the antibacterial activity, the Kruskall-Wallis and Dunn tests were performed; for the MTT, NR and ALP assays the data were analyzed by the tests Two Way ANOVA and Bonferroni (α=0.05).
Results: TCS+CaWO₄ presented the highest setting time and MTA HP the lowest value (P<0.05). Except for TCS, all materials presented radiopacity above 3 mm Al. The cements presented alkaline pH, antibacterial activity, and low solubility. The materials did not present cytotoxic effects in both cytotoxicity assays (MTT and NR). The greatest ALP activity occurred in 14 days, highlighting the cements TCS, TCS+ZrO₂ and TCS+CaWO₄ (P<0.05). TCS+ZrO₂, TCS+Nb₂O₅ and MTA HP showed higher formation of mineralized nodules than the negative control (P<0.05).
Conclusions: In conclusion, the experimental cements presented proper physicochemical properties, antimicrobial activity, cytocompatibility and induced mineralization in Saos-2, indicating their potential use as reparative materials.