Units of a large insurance holding company system are joining the movement to upgrade group dental plan benefits.

Delta Dental Insurance Company, Alpharetta, Ga., and Delta Dental of Pennsylvania, Mechanicsburg, Pa., subsidiaries of Dentegra Group Inc., San Francisco, say they will be offering tooth implant coverage as a standard benefit and adding coverage for more cleanings and exams for pregnant women.

New benefits for pregnant women will include an additional oral exam and an additional cleaning.

Pregnant patients with signs of gum disease will get coverage for more gum cleanings.

The Delta Dental plans are adding the extra coverage for pregnant members because of studies indicating that good dental health might reduce the risk that pregnant women will give birth too early.

The new benefits will be available for new commercial group clients with contracts that take effect on or after Jan. 1, 2008, in Alabama, Delaware, Florida, Georgia, Louisiana, Maryland, Mississippi, Nevada, New York, Pennsylvania, Texas, Utah, West Virginia and the District of Columbia.