Cytotoxicity of 35 Dental Resin Composite Monomers/additives in Permanent 3T3 and Three Human Primary Fibroblast Cultures

It was the purpose of this investigation to determine the cytotoxic effects (ED50 concentrations) of 35 monomers or additives identified in commercial dental resin composites. Monolayers of permanent 3T3 cells and three primary human fibroblast types derived from oral tissues (gingiva, pulp, and periodontal ligament) were used as test systems. All substances were tested in concentrations ranging from 0.01 to 5.0 mM. In general, ED50 values varied from 0.06 to > 5 mM. Within the groups of co(monomers), initiators, and cointiators, severe (e.g., Bis-GMA, UDMA, DMBZ, and DMDTA) or moderate (HEMA, BEMA, CQ, DMPT, and DMAPE) cytotoxic effects could be evaluated. Within the group of reaction/decomposition products, only moderate or slight effects were found (ED50: 0.7 to > 5 mM). The inhibitor BHT, the contaminant TPSb, and the photostabilizer HMBP, however, were highly cytotoxic in all cell cultures. In addition, the ED50 values of DBPO and HMBP significantly varied (0.43-3.8 mM, respectively, and 0.44-3.07 mM) with the applied cell culture. Our comprehensive screening shows that for several of the highly cytotoxic composite components, less cytotoxic alternatives are available. Furthermore, there was no cell type identified which was consistently less or more sensitive to the toxic effects of the tested compounds than the others. Primary human periodontal ligament and pulp fibroblasts, however, were found to be more sensitive than 3T3 and gingival fibroblasts to alterations from most tested substances.