Biological and biochemical characterization of 4-META/MMA-TBB resin

4-META/MMA-TBB resin has clinically favorable mechanical and bonding properties and undergoes unique, moisture-insensitive polymerization. To explore the potential usefulness of 4-META/ MMA-TBB resin as a pulp capping material, this study examined its biological and biochemical properties. Rat dental pulp cells were cultured on 4-META/MMA-TBB resin, resin-modified glassionomer (RMGI) cement, and a calcium hydroxide-based pulp capping material. The percentage of viable cells was considerably higher on 4-META/MMA-TBB resin than on RMGI and calcium hydroxide 24 h after seeding. The number of attached cells and their proliferative and alkaline phosphatase activities were significantly higher on 4-META/ MMA-TBB resin during the later stages of culture. Fourier transform infrared (FT-IR) and electron spin resonance (ESR) spectroscopic analyses showed that polymerization of the 4-META/MMA-TBB resin was faster and more complete than the RMGI and calcium hydroxide, with minimal production of free radicals. These results collectively and consistently demonstrated that 4-META/MMA-TBB resin possesses a higher level of biological and biochemical compatibility with dental pulp cells than RMGI cement and calcium hydroxide tested. Given the well-established mechanical advantages of 4-META/MMA-TBB resin, the current in vitro results serve as a basis to further explore this material as a pulp capping material and warrant in vivo studies. Keyword: cytotoxicity; pulp capping; resin-modified glassionomer; calcium hydroxide; free radical