INTELIHEALTH - People with dementia are at high risk of developing tooth decay in only a year, new research suggests.

Dementia is an illness that affects memory, attention, language and problem solving. It is more common in older people.

The study included 106 people who were referred to two hospital memory clinics. Their average age was about 82.

One group had Alzheimer's disease. A second group had dementia, but they were not diagnosed with Alzheimer's. People in the third group did not have dementia.

After one year, the researchers did follow-up exams on 77 of the original group. Overall, people had more tooth decay than at the start of the study. People who had dementia, but were not diagnosed with Alzheimer's disease., had the greatest increase in decay.

People with any type of dementia were also more likely than the others to have new decay or fillings.

Several factors increased the risk of new decay during the one-year period. They were:

• Having untreated decay on at least three tooth surfaces at the beginning of the study
• Having more than 20 teeth
• Being older than 80
• Having less than 8 years of formal education

The researchers say that older people who are diagnosed with dementia should be referred to a dentist as soon as possible.

The study appears in the November issue of the Journal of the American Dental Association.