Penetration of silver nitrate into bleached enamel, dentin, and cementum.
OBJECTIVE
To observe the effect of 10% carbamide peroxide bleaching agent on the enamel, dentin, and cementum of human teeth.


METHODS
Teeth were treated with one of two 10% carbamide peroxide bleaching agents (3M Zaris, 3M Espe; Nite White Excel, Discus Dental) for 2 hours/day for 7 or 14 days. Treated teeth and 10 additional nontreated teeth were immersed in 50% silver nitrate solution. The prepared surface was then viewed under a confocal laser scanning microscope, photomicrographs were taken, and the degree of penetration of silver nitrate into the structure of bleached teeth was determined.


RESULTS
No penetration was seen in enamel of any group, and statistical analysis showed a significant difference in the degree of penetration only between treated and nontreated groups of dentin and cementum (P <.05). No significant difference was seen between 7 and 14 days.


CONCLUSIONS
Although the effect was not significant, further investigation is needed to determine the effect of long-term treatment of carbamide peroxide on human tooth substance.
Iwamoto
Nanako
N
Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. nanako_iwamoto@kuraray.co.jp <iwamoto@kuraray.co.jp>
Shimada
Yasushi
Y
Tagami
Junji
J
D000077463:Carbamide Peroxide; D004396:Coloring Agents / Q000493:pharmacokinetics*; D003739:Dental Cementum / Q000187:drug effects; D003743:Dental Enamel / Q000187:drug effects; D003804:Dentin / Q000187:drug effects; D004338:Drug Combinations; D006801:Humans; D007180:Incisor / Q000187:drug effects*; D016877:Oxidants / Q000494:pharmacology*; D010545:Peroxides / Q000494:pharmacology; D012835:Silver Nitrate / Q000493:pharmacokinetics*; D013997:Time Factors; D014073:Tooth Bleaching; D014508:Urea / Q000031:analogs & derivatives / Q000494:pharmacology
D004396:Coloring Agents; D004338:Drug Combinations; D016877:Oxidants; D010545:Peroxides; D000077463:Carbamide Peroxide; D014508:Urea; D012835:Silver Nitrate