Time-course diffusion of hydrogen peroxide through human dentin: clinical significance for young tooth internal bleaching.
The purpose of this study was to record the time-course diffusion of hydrogen peroxide through human dentin from a peroxide carbamide gel designed for the walking bleach technique in order to determine its optimal renewal time. It was considered that the optimal renewal rate corresponded to the time necessary to achieve 80% of the maximal diffusion because a much longer time does not involve further significant diffusion. Thirty-six freshly extracted human premolars were used for this study. Eighteen were extracted for orthodontic reasons on patients under 20 years old (young-teeth group). Eighteen were extracted for periodontal reasons on patients between 40 and 60 years old (old-teeth group). The teeth were endodontically treated, and a flat defect was created at the enamel-cementum junction. The teeth were suspended in vials containing water, and the access cavities were filled with 20 microL of 20% hydrogen peroxide gel. The amount of diffusing hydrogen peroxide was assessed at 1 hour, 24 hours, 48 hours, and 120 hours. The diffusive flux and the maximal diffusion were calculated as well as the optimal renewal time. Hydrogen peroxide diffusion through young teeth lasted 352 hours but lasted 291 hours through old teeth. Diffusive flux and maximal diffusion were higher through young teeth than through old teeth. The optimal renewal time for young teeth was 33 hours and for old teeth was 18 hours.
Camps
Jean
J
Laboratoire IMEB, ERT 30, UFR Oontologie, Faculté d'Odontologie, Université de la Méditerranée, 27 boulevard Jean Moulin, 13385 Marseille CEDEX 5, France. jcamps2035@AOL.com
de Franceschi
Hélène
H
Idir
Fatiha
F
Roland
Christelle
C
About
Imad
I
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000077463:Carbamide Peroxide; D002648:Child; D003786:Dental Pulp Cavity / Q000378:metabolism; D003804:Dentin / Q000378:metabolism*; D004058:Diffusion; D004338:Drug Combinations; D006801:Humans; D006861:Hydrogen Peroxide / Q000493:pharmacokinetics*; D008422:Materials Testing; D008875:Middle Aged; D016877:Oxidants / Q000493:pharmacokinetics*; D010545:Peroxides / Q000493:pharmacokinetics; D012390:Root Canal Therapy; D013997:Time Factors; D014073:Tooth Bleaching / Q000379:methods*; D019237:Tooth Cervix / Q000378:metabolism; D019553:Tooth, Nonvital / Q000378:metabolism; D014508:Urea / Q000031:analogs & derivatives / Q000493:pharmacokinetics
D004338:Drug Combinations; D016877:Oxidants; D010545:Peroxides; D000077463:Carbamide Peroxide; D014508:Urea; D006861:Hydrogen Peroxide