Cytotoxicity of 2 Bleaching Agents: An In Vitro Study

Tooth bleaching procedures have become very popular since their first introduction in dental clinical practice. There are concerns about the effects of exposure of oral tissues to bleaching agents. The purpose of the present study was to determine the cytotoxic effect of 2 bleaching agents (sodium perborate and carbamide peroxide) against 2 fibroblastic cell lines. BHK21/ C13 baby hamster kidney fibroblasts and RPC-C2A rat pulp cells were used for the experiment. The cells were grown as monolayer cultures at 37°C in an atmosphere containing 5% CO2 in air, and 100% relative humidity. Cells were plated in multiwell plates and serial dilutions of the bleaching agents were prepared and placed in contact with cell cultures. The anti-proliferative effect was determined after 24 and 48 hours of exposure by means of the colorimetric sulphorodamine B assay, in reference to controls. BHK21/C13 and RPC-C2A reacted to the bleaching agents with different intensity. Cell proliferation was reduced compared to the controls after 24 and 48 hours of exposure in both cell lines. The cytotoxic effect was concentrationand time-dependent. Sodium perborate was the most potent material tested.