There are numerous materials used to provide temporary coverage for teeth while permanent restorations are being fabricated. The biocompatibility of these materials is important for the protection of teeth and gingiva, but there is little information on this subject. This study aimed to examine possible time-dependent toxic effects of provisional crown and bridge restoration materials, manipulated intraorally or extraorally, on epithelia cells. A total of 20 discs, 4 sample discs from each product having dimensions of 4 mm diameter and 2 mm thickness, were prepared. After sterilization, toxicity of these discs was evaluated in the Madin Darby Bovine Kidney (MDBK) cell line. Morphological cell changes were observed microscopically at the 3rd, 6th, 12th, and 24th hours by the filter diffusion test method. After the 3rd hour, Artglass and Structur produced cytotoxic symptoms. Temdent had the least toxic effects at the end of the 12th hour. However, after the 24th hour, the toxic values were similar for all materials. The results of this study show that although the toxicity response of chemically and light curing materials had changed in different time periods, all of them had the same toxic effects at the end of the 24th hour.