EFFECTS OF DENTIN BONDING AGENTS ON MACROPHAGE MITOCHONDRIAL ACTIVITY

Dentin bonding agents (DBA) have been considered for use as root-end f illings. Previous studies have documented the release of DBA component s in vivo and in vitro, but the biological implications are not clear. The macrophage is important in wound healing, and likely to be import ant in any inflammatory response. Therefore, this study determined the concentrations of the components of DBAs that suppress the mitochondr ial activity of human macrophages in vitro. THP-1 macrophages were cul tured in the presence of four DBA components (2-hydroxyethyl methacryl ate (HEMA), 4-methacryloxyethyl trimellitate anhydride (4-META), bisph enol-glycidylmethacrylate (Bis-GMA), and urethane dimethacrylate (UDMA )) at various concentrations and for varying durations. Residual effec ts were also measured after the resins were removed. Controls received only the vehicle solution, ethanol or water. THP-1 mitochondrial acti vity was estimated using the MTT assay, and the 50% toxicity concentra tions (TC50) were determined graphically. Resin components suppressed the mitochondrial activity of macrophages at different concentrations (TC50) values for HEMA (10,000 mu mol/L), 4-META (3,800 mu mol/L), Bis -GMA (130 mu mol/L), and UDMA (110 mu mol/L) at 24 h, and the effect w as time-dependent. Residual effects were observed for all resins.