NEW YORK (Reuters Health) ¿ The added fluoride in many Americans' drinking water may be protecting older adults' teeth from decay, a study suggests. Fluoridated drinking water has been credited with cutting rates of tooth decay among Americans, but the benefit is often thought of as being largely for children.

However, older adults may stand to gain as much or more, researchers report in the Journal of Public Health Dentistry.

In a study looking at dental care costs among nearly 52,000 members of one insurance plan, researchers found that those living in areas with fluoridated drinking water spent less on dental fillings than those without fluoridated water supplies.

When the researchers looked at plan members by age, however, it turned out that the benefit was seen in children and, to an even greater extent, in adults older than age 58.