Characterization of nano α-TCP: Setting time, antibacterial activity and cytotoxicity on fibroblast cells

Background Nano α-Tricalcium Phosphate (nano α-TCP) is a potential pulp capping material due to its calcium/phosphate ion release, antibacterial properties, and biocompatibility. Objectives To evaluate the setting time, antibacterial activity against Streptococcus mutans , and cytotoxicity of nano α-TCP. Methods Setting time was measured using the Vicat test. Antibacterial activity was assessed by direct contact testing at concentrations of 100%, 50%, and 25%. Cytotoxicity on fibroblasts was evaluated using the CCK-8 assay after 24 and 72 hours. Results Nano α-TCP at 100% concentration showed the strongest antibacterial effect and the fastest setting time. All tested concentrations maintained high fibroblast viability, indicating low cytotoxicity. Conclusion Nano α-TCP effectively inhibits S. mutans , sets rapidly, and is biocompatible, supporting its potential as a pulp capping material.