According to a new study appearing in the April issue of the Journal of Dental Research, cigarette smoking can more than double the risk of needing root canal treatment. 'The findings substantiate what most of us already know: smoking is detrimental to your health,' said Elizabeth Krall Kaye, a professor at Boston University's School of Dental Medicine in Boston, and the lead author of the study. 'But because root canal treatment is so common—it's estimated that half of US adults have experienced one by age 50 — I think people can relate to it more than lung cancer and 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 findings are based on data collected during Veterans Affairs Normative Aging and Dental Longitudinal studies at the VA Boston Healthcare System in Boston. The study, which began in 1968, tracked how men's dental and physical health progressed over the course of 30 years. Men visited the study site every three years where they were checked for signs of caries, or cavities, tooth restorations and periodontal disease. Clinicians also took mouth x-rays and documented their smoking habits, including frequency and type of tobacco. From the data, the researchers were able to identify approximately 811 men with teeth that were free of root canal treatment at the study's beginning.

The researchers found that cigarette smokers are 70% more likely to need root canal treatment than non-smokers. Besides identifying the risk for root canal treatment, the research also showed the positive effects of quitting. 'The total amount time smoked and total time they remained smoke-free was directly related to their risk,' said Dr Kaye. '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 non-smokers, 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. The good news is that after being smoke-free for nine years, the risk returned to the level of men who never smoked.'

Dr Kaye said that while the research doesn't explain why the risk is increased among cigarette smokers, they suspect that the body's reduced infection-fighting capabilities as a result of smoking may contribute. 'Other studies have also suggested that smokers experience more dental cavities, which is a major reason for root canal treatment,' said Dr Kaye. 'Hopefully future research will be able to identify the mechanisms that explain why cigarette smokers have more root canal treatments.'