An insurer is taking a new approach to holding down the cost of dental coverage.

Aetna Inc., Hartford, says its new Aetna Dental Preventive Care is a true insurance plan, rather than a discount plan. But the plan will pay only for preventive care and for diagnostic procedures, not for fillings and other treatments, the company says.

Members of the new plan can get free cleanings, X-rays and fluoride treatments from Aetna network dentists, Aetna says.

Aetna network dentists will offer discounts for services such as filling cavities and treating discoloration of teeth that are not covered by the plan, the company says.