Smokers who give up are much less likely to lose their teeth prematurely than those who do not kick the habit, research shows.
Gum disease can lead to teeth falling out
A team at the University of Newcastle upon Tyne studied cigarette smokers with chronic gum disease - which can lead to loss of teeth - over one year.
They found some symptoms were more likely to improve in the people who quit during the study period.
The research is published in the Journal of Clinical Periodontology.
Smokers are up to six times more likely to develop gum disease than non-smokers.
It is thought that smoking depresses the ability of the immune system to fight infection.
Gum disease is initiated by a build up of bacteria in plaque, the sticky white substance that accumulates on the teeth if they are not properly cleaned.
The bacteria cause the gums to become inflamed, and they begin to recede from the teeth.
At the same time, the bone that holds the teeth in place is gradually destroyed so that over a number of years, teeth may start to become loose and may fall out, or need to be extracted.
The disease is usually painless and thus only discovered when people visit their dentist.
Lead researcher Dr Philip Preshaw, said: "Dentists have known for some time that smokers have worse oral and gum health than non-smokers but for the first time we have shown that quitting smoking together with routine gum treatment results in healthier gums.
"It is very important to look after your teeth, because losing them will have a huge influence on your life.
"Not only will this affect your appearance, it can also impact on your confidence, lifestyle, and so much more."
One of Dr Preshaw's patients, Trevor Richardson gave up the habit after smoking for around 40 years.
He said: "I started to realise that something wasn't quite right with my gums and teeth, and my dentist referred me to the hospital.
"I decided to give up on the first day of the treatment - and I haven't smoked since.
"Not only did the health of my teeth and gums improve, I also started to taste food properly and I looked and felt healthier in general."
Amanda Sandford, of the anti-smoking charity ASH, commented: "Dentists must do all they can to inform patients of the risks and to assist patients who smoke to stop before the disease takes hold."