RESUMEN
Cell culture has been used to study the cytotoxicity of denture base resins. Indeed, denture cleansers and their effects on the resin cytotoxicity need deep concern. The aim of the present in vitro study was to investigate the cytotoxic effect of a heat cured denture base resin treated with two denture cleansers on mouse L-929 fibroblasts. Under aseptic conditions, sample disks of a heat treated resin were prepared, following manufacturers' instruction and divided into 12 groups of ten as follows: I] soaking in 1% sodium hypochlorite, II] soaking in alkaline peroxide solution, and III] soaking in water bath for 1, 24, 72 hours and a week. Suspensions of the fibroblasts with acrylic disks were put in 24-well culture plates, and the culture media containing RPMI-1640 environment plus antibiotics and 10% fetal bovine serum were added. After incubation of the plates at considered time intervals, cytotoxicity of the resin was carried out by MTT assay. A significant difference was noticed for solutions in relation to the biocompatibility of the acrylic resin samples at determined time intervals. The cleansers' soaking samples showed higher cytotoxicity in comparison to those immersed in water at each time interval. The difference between cytotoxic effects of the samples immersed in water or cleansers were significant after 72 hours and one week. Overnight immersion in alkaline peroxide and 1% hypochlorite solutions increased the cytotoxicity of the heat cured acrylic resin, but water storage improved the biocompatibility of the material tested