Link May Exist Between Passive Smoking And Periodontal Disease, Researchers Say

The study, which involved analyzing data from the Third National Health and Nutrition Examination Survey from 1988 to 1994, or NHANES III, revealed between a 50 percent and 60 percent increased risk of periodontal disease among non-smokers who are around smokers than those who are not.

Researchers, who are affiliated with the UNC School of Dentistry, said their findings provide evidence of an association but do not prove it.

A report on the research appears in the February issue of the American Journal of Public Health. Authors are Drs. Samuel J. Arbes Jr. and Helga Agustsdottir, former postdoctoral fellows with the Center for Oral and Systemic Diseases, and Dr. Gary D. Slade, associate professor of dental ecology. "We found that among adults in the United States who had never smoked cigarettes, 11 percent of those exposed to environmental tobacco smoke in their homes or at work had periodontal disease, and their risk was about 1.5 times higher than for people not exposed," Arbes said. "Even though this increase in risk is much smaller than the increase in risk associated with active cigarette smoking - up to five times greater - environmental tobacco smoke could account for many cases of gum disease nationwide."

Researchers evaluated NHANES III data on a subset of 6,611 U.S. residents age 18 and older who had never smoked or used other forms of tobacco. The survey is the most recent in a series of national surveys conducted by the federal government to help assess the health in this country. "One advantage to using the NHANES III data is that it is a sample of the total civilian, non-institutionalized population of the nation," Arbes said. "Therefore, our results can be generalized to the U.S. population."

About a third of non-smoking adults in the study were exposed to environmental tobacco smoke, which also is called "passive smoking," at home or at work, he said. Investigators did not measure the amount.

How could the smoke cause gum disease? "Active smoking is one of the most important, if not the most important, risk factor for periodontal disease, and many studies have examined its effects," Arbes said. "One of the many chemicals that gets into the body when a person actively smokes or breathes someone else's smoke is nicotine. "Earlier studies have suggested that nicotine in cigarette smoke impairs the immune system and causes blood vessels to constrict, including blood vessels in the tissues around the teeth. This causes a decrease in oxygen in these tissues which, along with an impaired immune system response, creates a favorable environment for bacteria that cause periodontal disease."

Undoubtedly, the real picture is much more complicated, and the mechanism by which other people's smoke may promote the illness has not been studied, he said. Periodontitis destroys soft tissues and bone that support the teeth, which often leads to tooth loss.

"We strongly believe that it is premature to claim that passive smoking causes periodontal disease or to make any policy recommendations," Arbes said. "However, we do feel that it is reasonable to use these findings to repeat the known oral health hazards of active tobacco consumption. We also hope the findings further motivate dental health providers to promote tobacco cessation in their practices."

The National Institute of Dental and Craniofacial Research supported the study.