The aim of this study was to evaluate the cytotoxicity of several tooth whitening material, carbamide peroxide 10%, 15%, 20% and hydrogen peroxide 38% toward BHK-21 cell using MTT assay. Each well of microplates which used for the test were aliquotted BHK-21 cell suspension, after that the test solution were added to eight well each group, respectively. Microplates were incubated at 37⁰C in 5…