1910 Degradation of Hydrogen Peroxide and Carbamide Peroxide in Vitro

J.S. SORHUS, and B. MATIS, Indiana University School of Dentistry, Indianapolis, USA

As the public demand for whiter teeth increases, many new companies are scrambling to enter the whitening revolution . It is imperative that the products they produce be accurate to the stated peroxide level on the box.

Objective: The purpose of this study was to assess whether or not the actual peroxide levels, as reported by the manufacturer, were accurate.

Methods: The US Pharmacopeia method was utilized to measure the amount of both carbamide peroxide (CP) and hydrogen peroxide (HP). This method consists of the sample being titrated to end point with a 0.025 N sodium thiosulfate solution. All tests were conducted in triplicate to ensure accuracy and, where possible, were compared to stated levels by the manufacturer. All products were tested within the stated use life printed on the package.

Results: There were 50 products tested with 8 being over-thecounter whitening agents, 35 were dentist prescribed at-home products, and 7 were in-office use products. The stated concentration levels of the products were from 10%CP to 30%CP and from 4.5%HP to 40%HP. The results showed that of the 13 products with 10%CP (only ADA accepted level deemed safe and effective), 6 had values that were >1% of their stated level. In the 15-16%CP range, 5 of the 10 samples had values that were >1% of their stated value. In the above 20%CP category, 50% had values that were >1% difference. Of the 9 products containing HP (including in-office and at-home), 7 of the products were within 1% of their stated value. and the 2 products that were >1% had only a minor deviation.

Conclusions: The results of this study indicates that there exists a significant quality-control issue with some companies in producing the desired %peroxide content, or that the degradation level of the product is more rapid than companies have expected. Seq #211 - Bleaching Materials - Properties 10:15 AM-11:30 AM, Friday, 12 March 2004 Hawaii Convention Center Exhibit Hall 1-2