Cytotoxicity and dentin permeability of carbamide peroxide and hydrogen peroxide vital bleaching materials, in vitro.
There has been recent concern about the inadvertent exposure of dentin with patent tubules as well as gingiva to bleaching systems containing 10-15% carbamide peroxide or 2-10% hydrogen peroxide for more than a few minutes. The aims of the present study were: (1) to determine the cytotoxicity of dilutions of hydrogen peroxide in cell culture; (2) to measure hydrogen peroxide diffusion from bleaching agents through dentin in vitro; and (3) to determine the risk of hydrogen peroxide-induced cytotoxicity from exposure of dentin to these vital bleaching agents. The 50% inhibitory dose (ID50) of hydrogen peroxide to succinyl dehydrogenase activity in cultured cells was found to be 0.58 mmol/L after 1 h. All bleaching materials demonstrated diffusion of hydrogen peroxide through dentin in an "in vitro pulp chamber" device. The one- and six-hour diffusates of all bleaching agents through 0.5-mm dentin exceeded the ID50 in monolayer cultures. Inhibition of succinyl dehydrogenase activity corresponded to the amount of hydrogen peroxide that can rapidly diffuse through dentin in vitro and reach concentrations which are toxic to cultured cells in less than 1 h.
Hanks
C T
CT
Department of Oral Medicine, University of Michigan School of Dentistry, Ann Arbor 48109-1078.
Fat
J C
JC
Wataha
J C
JC
Corcoran
J F
JF
D016475:3T3 Cells; D000328:Adult; D000704:Analysis of Variance; D000818:Animals; D000077463:Carbamide Peroxide; D003782:Dental Pulp / Q000187:drug effects; D003804:Dentin / Q000187:drug effects; D003806:Dentin Permeability; D004338:Drug Combinations; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D009994:Osmolar Concentration; D010545:Peroxides / Q000633:toxicity*; D012044:Regression Analysis; D014073:Tooth Bleaching / Q000009:adverse effects*; D014508:Urea / Q000031:analogs & derivatives* / Q000633:toxicity
D004338:Drug Combinations; D010545:Peroxides; D000077463:Carbamide Peroxide; D014508:Urea; D006861:Hydrogen Peroxide