Demineralization effects of 10 percent carbamide peroxide.
OBJECTIVE
The purpose of this in vitro study was to measure the amount of calcium lost from enamel exposed to a 10% carbamide peroxide solution.


METHODS
Nine teeth (3 incisors, 2 premolars, 4 molars) were sectioned to serve as paired test and control specimens. Each tooth half was coated with wax, leaving a uniform 3 mm x 4 mm window of exposed enamel. Test specimens were placed in culture tubes with 1.00 ml of deionized water and 0.02 ml of 10% carbamide peroxide for 6 h; controls were exposed to water alone. Calcium concentrations in the solutions were measured using a Perkin-Elmer 5100 atomic absorption spectrophotometer.


RESULTS
Teeth exposed to carbamide peroxide lost an average of 1.06 micrograms/mm2 of calcium. This amount of loss was significantly greater than controls (p < 0.001), according to ANOVA. For comparison, teeth were exposed to a cola beverage for 2.5 min, the time equivalent of drinking a 16 oz. beverage. The amount of calcium lost from these teeth was also about 1 microgram/mm2.


CONCLUSIONS
Teeth exposed to 10% carbamide peroxide lost calcium. However, the amount of loss was small, and may not be clinically significant.
McCracken
M S
MS
Department of Restorative Dentistry, UAB School of Dentistry, South Birmingham, Alabama 35294-0007, USA.
Haywood
V B
VB
D000704:Analysis of Variance; D001641:Bicuspid; D002118:Calcium / Q000032:analysis; D000077463:Carbamide Peroxide; D002253:Carbonated Beverages / Q000009:adverse effects; D003743:Dental Enamel / Q000737:chemistry / Q000187:drug effects; D004338:Drug Combinations; D006244:Hardness; D006801:Humans; D007180:Incisor; D008963:Molar; D010545:Peroxides / Q000008:administration & dosage / Q000009:adverse effects*; D013054:Spectrophotometry, Atomic; D013997:Time Factors; D014073:Tooth Bleaching / Q000009:adverse effects*; D017001:Tooth Demineralization / Q000139:chemically induced* / Q000378:metabolism; D014508:Urea / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*
D004338:Drug Combinations; D010545:Peroxides; D000077463:Carbamide Peroxide; D014508:Urea; D002118:Calcium