Table of Contents

Cover Story
Restorative

Inside Dentistry

October 2008, Volume 4, Issue 9
Published by AEGIS Communications

Use of Hydrogen Peroxide-Based Tooth Whitening Products and Its Relationship to Oral Cancer

Howard E. Strassler, DMD

Munro IC, Williams GM, Heymann HO, et al. Food Chem Toxicol. 2006;44(3):301-315. Republished in: J Esthet Restor Dent.2006;18(3):119-125.

Abstract

Tooth whitening products containing hydrogen peroxide or carbamide peroxide were evaluated in this review for potential oral cancer risk from their use. Hydrogen peroxide is genotoxic in vitro, but not in vivo. Hydrogen peroxide was not considered to pose a genotoxic risk to humans. The animal toxicology data relevant to the assessment of the carcinogenicity of hydrogen peroxide do not indicate that it has significant carcinogenic activity at any site, including the oral cavity. Hydrogen peroxide was found to enhance the carcinogenic effects of potent DNA-reactive carcinogens in experimental animals. However, these experimental conditions are artificial as they are related to high exposures and are of no relevance to potential human exposures to low quantities of hydrogen peroxide from the use of tooth whitening products. Clinical data on hydrogen peroxide-containing tooth whitening products show no evidence for the development of preneoplastic or neoplastic oral lesions. Exposures to hydrogen peroxide received by the oral cavity are exceedingly low, of short duration (30 min to 60 min), and could not plausibly enhance any carcinogenic risk associated with exposure of the oral cavity to chemicals in cigarette smoke or to alcohol, both known risk factors for the development of oral cancer.

Commentary

The first abstract reviewed in this column provides clinical data on the use of an over-the-counter (OTC) combined toothpaste and whitening strip for oral health and whitening. This family of products is meant to be used every day for the toothpaste and once a week for the hydrogen peroxide whitening strip. There has been a question concerning the long-term use of both professionally dispensed and OTC carbamide and hydrogen peroxide whitening agents and a patient’s risk for oral cancer. These whitening products have been used in dentistry with tray bleaching and OTC distribution for more than 15 years. Whenever a question of safety arises, a comprehensive systematic literature review should be done to evaluate all available literature and research. The data is in-sufficient for making a decision on the potential carcinogenicity of hydrogen peroxide to humans. Individuals at greatest risk of oral cancer (> 90%) are smokers. Also, excessive alcohol consumption is a pronounced oral cancer risk. Should we be concerned?

This comprehensive systematic review of more than 100 sponsored clinical studies with approximately 4,000 subjects provides insight into whether patients are at risk for oral cancer from use of peroxide-based tooth-whitening agents. This review article, based on extensive analysis and review, has clinical significance: As dentists, we can feel confident in the safety of hydrogen and carbamide peroxide whitening agents. In fact, the use of peroxide-containing tooth whitening products does not appear to pose an increased risk for oral cancer in the general population, including those people who are alcohol abusers and/or heavy cigarette smokers.

About the Author

Howard E. Strassler, DMD
Professor and Director of Operative Dentistry
Department of Endodontics, Prosthodontics and Operative Dentistry
University of Maryland Dental School
Baltimore, Maryland