This could be partly due to the fact that people under stress tend to grind their teeth.

However, the risk does not apply to those people who have learned to live with their financial problems.

Researchers, whose study was published in the Journal of Periodontology, found that people who reported high levels of financial strain and an inability to deal positively with their problems had higher levels of the typical signs of gum disease than those with fewer problems.

People who dealt with their financial strain in an active, practical way had no more risk of severe periodontal disease than those without money problems.

Long-term pressure

Dr Robert Genco, chair of the oral biology department at The State University of New York at Buffalo, said: "Financial strain is a long-term, constant pressure.

"Our studies indicate that this ever-present stress and a lack of adequate coping skills could lead to altered habits, such as reduced oral hygiene or teeth grinding, as well as salivary changes and a weakening of the body's ability to fight infection."

Gum disease is associated with a higher risk of heart disease, respiratory disease and diabetes complications.

Dr Genco and his colleagues are following more than 1,400 people between the ages of 25 and 74 in the ongoing study, which is one of the first to examine the relationship between gum disease and stress.

Psychological tests were given to identify and weigh the causes of stress and to measure the ability to cope with problems.

To measure financial strain, participants in the study answered nine questions, including:

• At the present time, are you able to afford a home that is large enough?
• Do you have difficulty in meeting monthly payments of your family bills?

• How often do you not have enough money to afford the kind of food, clothing, medical care, or leisure activities you and your family need or want?

Dr Geoff Craig, chairman of the British Dental Association health and science policy group, said: "People who clench and grind their teeth while they are asleep can cause quite a lot of damage to the tooth attachment.

"If they also happen not to be cleaning their teeth and allowing bacterial plaque to build up that can accelerate the disease process."