Introduction It is believed that teeth whitening might have a beneficial effect in reducing oral microbes (Streptococcus sp., Actinomyces sp., Bacteroides sp., Fusobacteria sp., Lactobacillus sp., and Candida sp.) 4. However, teeth whitening agents are loosely regulated by the Food and Drug Association (FDA), so detrimental effects are unknown 2. Objective The purpose of this study is to investigate the potential mutagenic, bacteriostatic and disinfectant effects of teeth whitening agents (Colgate Simply White ®, Natural White ® and Day White ® ). Methods 1.Ames Test Ames test uses histidine-dependent strains of Salmonella typhimurium (TA 98 and TA 100) to test for mutagenicity 3. Salmonella bacteria were exposed to different dilutions of teeth whitening products as well as to positive and negative controls. Colonies were counted after 2 days of incubation at 37 o C. 2. Kirby Bauer Plates of brain infusion agar were streaked with Streptococcus sobrinus ATCC (subspecies of S. mutans, the main causative agent of tooth decay). Discs with different teeth whiteners at various dilutions were placed onto the agar 4. Zones of inhibition were observed. 3.Saliva Samples Saliva samples were taken for five days before, during and after the use of a teeth whitening product (Natural White ® ). The saliva samples were streaked onto a blood agar plate and the colonies were counted after two days of incubation at 37 o C. Results The teeth whiteners showed no mutagenic properties. See Figure 1 and 2. At ¼ dilution, 50 l of teeth whitener showed a zone of inhibition. See Figure 3. The teeth whiteners slightly inhibited bacterial growth during the time of use. See Table 1. Figure 1. Mutagenic activity of teeth whitening products on S. typhimurium TA 100. Figure 2. Mutagenic activity of teeth whitening products on S. typhimurium TA 98. Conclusion Teeth whitening agents have no toxicological affects, although of all the whiteners, Natural White ® showed the most potential for mutagenicity. The Kirby Bauer and saliva sampling both showed that the teeth whiteners displayed antibacterial properties which could possibly decrease the incidence of cavities. Future Studies Experiment with TA 102, a more sensitive strain to oxidizing agents. Characterize and identify oral normal flora. Perform comparative analysis of bacterial sensitivity to teeth whitening products. Acknowledgements Christine Anderson, Caroline Fardy, Tina Consalvo, and Dr. Ron Smith References 1. Dr. J.J. Edderai (March 16, 2004). 2. U.S. Food and Drug Association (March 15, 2004). 3. Maron, D., and Bruce Ames Revised methods for the Salmonella mutagencitiy test. Mutation Research, 113: Tortora, Funke and Case Microbiology: An introduction. 7 th edition. Addison-Wesley, NY, pp. 408, 567. Studies on Mutagenic Activity and Bacterial Flora in Teeth Whitening Agents Lorilee Consalvo Supervisor: Dr. Naowarat Cheeptham Co-Supervisor: Joanna Urban Department of Biological Sciences, The University College of the Cariboo Before X organisms/ L During X organisms/ L After X organisms/ L After 1 Before 1 Figure 3. (A) Inhibitory zone against the growth of S. sobrinus when 1/4 dilution of Day White used. (B) No inhibition of growth against S. sobrinus when 1/8 dilution of Day White used. Table 1. Number of bacterial colonies present before, during, and after use of Natural White. AB