Smoking may be responsible for more than half of the cases of gum disease among adults in the US, say researchers.
The study found that current smokers are about four times more likely than people who have never smoked to have advanced periodontal (gum) disease.
In addition to being a major cause of tooth loss, periodontal disease has been linked to increased risk of heart disease, stroke, diabetes, respiratory disease and premature babies.
However, 11 years after quitting, former smokers were no more likely than non-smokers to suffer from bad gums.
Researchers from the Centers for Disease Control and Prevention analysed US government health data on 13,650 people aged 18 and older who had their own teeth.
Lead researcher Dr Scott Tomar said: “Cigarette smoking may well be the major preventable risk factor for periodontal disease.
“The good news is that quitting seems to gradually erase the harmful effects of tobacco use on periodontal health.”
The researchers also found that the odds of developing gum disease were increased still further by heavy smoking.
Dose effect
Smokers who smoked less than half a pack per day were almost three times more likely than nonsmokers to have periodontitis.
But those who smoked more than a pack and a half per day had almost six times the risk.
Jack Caton, president of the American Academy of Periodontology, said: “Everyday periodontists see the destruction smoking causes in the mouths of their patients.
“I hope the staggering statistics from this study will compel even more dental care providers to get involved in tobacco cessation efforts.”
Smoking reduces the delivery of oxygen and nutrients to the gums.
This damages the healing process, and makes smokers’ gums more susceptible to infection.
In addition to being a major cause of tooth loss, periodontal disease has been linked to increased risk of heart disease, stroke, diabetes, respiratory disease and premature babies.
The research was welcomed by the British Dental Association.
Chief executive John Hunt said: “This is very useful research showing just how bad smoking can be for your gums. If you want to keep your teeth, don’t smoke.”