Dental restorative biomaterials induce glutathione depletion in cultured human gingival fibroblast: Protective effect of N-acetyl cysteine

Eight biomaterials eluted from four different types of dental restorative b iomaterials, that is, from glass ionomer cement (GIC: Ketac-fil and Fuji II ), resin-modified glass ionomer cement (RM-GIC: Fuji II LC and Photac-fil), composite (Z100 MP and Tetric-flow), and compomer (Compoglass F and F-2000 ), were studied for their cytotoxic properties in relation to glutathione ( GSH) content in cultured human gingival fibroblasts. Z100 MP, Tetric-flow, and Compoglass F were less cytotoxic than the others, with a toxic concentr ation of 50% (TC 50) > 24% (of eluate), as determined by the MTT test. F-20 00, Tetric-flow, and the other biomaterials were relatively more cytotoxic (TC 50 = 9-16%). With the exception of Z100 MP, all the biomaterials induce d a depletion of cellular glutathione (GSH) that was variable depending upo n the biomaterial eluates. The strongest GSH depletion was with F-2000, Fuj i II, and Photac-fil. GSH depletion, with Compoglass and F-2000, was rapid- detectable after one h of cell treatment and complete within 3 h-whereas a longer period of incubation was required for the other biomaterials. Intere stingly, the drug cytotoxic effects induced by all the biomaterials were pr evented by cell treatment with the antioxidant N-acetylcysteine (NAC). This study provides evidence that the cytotoxic property of dental restorative biomaterials is associated with depletion of the glutathione level in gingi val fibroblasts. While the molecular mechanisms of this phenomenon require further investigations, our data suggest that NAC may be useful in preventi ng the cellular damage induced by dental restorative biomaterials. (C) 2000 John Wiley & Sons, Inc.