EFFECTS OF UNPOLYMERIZED RESIN COMPONENTS ON THE FUNCTION OF ACCESSORY CELLS DERIVED FROM THE RAT INCISOR PULP

Monomeric resin components from dental composites are toxic to fibrobl asts in culture and thus may interfere with the local immune system of the pulp, reducing its effective defense potential, either by cytotox icity or by a more specific immune mechanism. Therefore, the present s tudy was undertaken to observe the cytotoxic effects elicited by certa in unpolymerized components of resin composites upon the function of a ccessory pulp cells in mitogen-induced proliferation of T-lymphocytes. Accessory cells from the rat incisor pulp were released following enz ymatic digestion with collagenase. The assay included incubation of th ese cells with purified T-lymphocytes from cervical lymph nodes for 72 h in the presence of different concentrations of the resin components . The proliferative T-lymphocyte response was monitored by H-3-thymidi ne incorporation. Initially, we conducted experiments on spleen cells to determine the proper concentration intervals for suitable testing o f the resin components. To assess the individual susceptibility of acc essory cells and T-lymphocytes, we pre-treated each of these cells wit h some of the test materials prior to assay. At low concentrations, ur ethane dimethacrylate (UDMA), bis-glycidyl methacrylate (bis-GMA), tri ethylene glycol dimethacrylate (TEGDMA), and bis-phenol A (BPA) increa sed spleen cell proliferation to concanavalin A (con A). Purified T-ly mphocytes stimulated by pulpal cells did not show enhanced responses t o UDMA, bis-GMA, glycidyl methacrylate (GMA), or N,N-dihydroxyethyl-p- toluidine (DHEpT). At higher concentrations, all substances except cam phoroquinone (CAMP) showed inhibitory effects in both test systems. Th e in vitro study shows that resin components can evoke either immunosu ppression or immunostimulation on mitogen-driven proliferation of puri fied T-lymphocytes and spleen cells.