Feb. 24, 2006
 
HEALTH: Smoking Raises Root-Canal Risk
 
By Lee Bowman
Scripps Howard News Service
 
If the discolored teeth, ashtray smell and threat of emphysema and lung cancer aren't incentive enough to stop smoking cigarettes, here's one more: If you smoke, there's nearly double the risk of having a root canal than if you don't.
 
Those odds, reported during a briefing on oral health sponsored Thursday, Feb. 23, 2006 in New York by the American Dental and American Medical associations, are based on research at Boston's VA Healthcare System that tracked the dental health of more than 800 men over almost 30 years. "Men who smoke cigarettes have almost twice the risk than men who have never smoked," said Elizabeth Krall Kaye, an epidemiologist with the VA and a professor of health policy and health services research at Boston University's dental school.
 
"We found that cigarette smokers are 70 percent more likely to need root-canal treatment than nonsmokers."
 
Once every three years, the men in the study got a dental checkup and mouth X-rays and gave a report on their tobacco use, including frequency and type of smoking. None of the men -- who ranged in age from 24 to 84, and were all veterans but not regular VA patients -- had had a root canal when they were first examined.
 
Root-canal treatment is necessary when the soft tissue of the tooth, containing nerves, blood vessels and connective tissue, becomes inflamed from bacterial infection. A dentist or endodontist has to remove the infected tissue, clean the space and fill or cap the tooth to prevent further infection. Even with painkillers, it is a procedure few patients wish to repeat.
 
Out of 18,893 teeth tracked through the study, Kaye and two dental residents who reviewed the X-rays found that 998 teeth had undergone a root canal by the end of the study. The data on those patients was matched with each man's smoking habits. About a third of the men had never smoked; a third smoked cigarettes and another third were either former smokers or used tobacco other than cigarettes.
 
"The findings substantiate what most of us already know," Kaye said. "Smoking is detrimental to your health. But because root-canal treatment is so common -- it's estimated that half of U.S. adults will have one by age 50 -- I think people can relate to more than lung cancer or other smoking-induced conditions.
 
"No matter what your age, you may need a root canal, and as our research shows, smoking increases your risk."
 
The research, which is to be published in the April issue of the Journal of Dental Research, also showed that men who smoked cigars and pipes had only a slightly elevated risk for root canals compared to nonsmokers. But Kaye said because only a small number of the subjects used tobacco that way, "we cannot be absolutely positive there's an increased risk at all."
 
Kaye and her colleagues estimated that of the 400 million root canals that have ever been done on American adults, some 25 million could have been avoided if the patients hadn't smoked. "It could save the country about $1 billion a year in dental care if no one smoked," she said.
 
Along with identifying increased root-canal risk from smoking, the study also underscored the benefits of quitting: the total amount of time a person smoked and the total time they remained smoke-free directly affected the risk, as did whether they smoked more or less than a pack a day.
 
"For example, the teeth of a man who smoked for less than four years had a likelihood of treatment that was 20 percent greater than that of nonsmokers, but the risk doubled in men who smoked anywhere between five and 12 years and was 120 percent greater for men who smoked for more than 12 years," Kaye said. "The good news is that after being smoke-free for nine years, the risk returned to the level of men who never smoked."
 
The research doesn't explain why root-canal risk goes up in smokers, but other studies have indicated that smokers have more dental cavities, which are a major reason for root canals being done. Also, Kaye said, it may be that "the body's reduced infection-fighting capabilities as a result of smoking may contribute."
 
On the Net: http://www.ada.org
 
Contact Lee Bowman at BowmanL@shns.com