Two dental insurers are ramping up the battle against periodontal disease.

Metropolitan Life Insurance Company, a unit of MetLife Inc., New York, has teamed up with PreViser Corp., Mount Vernon, Wash., a software firm, to encourage dentists to use a Web-based PreViser system that can help them diagnose potentially serious oral diseases and identify patients who are at highest risk for contracting new gum ailments.

Principal Financial Group Inc., Des Moines, Iowa, is tackling the issue by offering extra help to people most at risk from gum ailments such as gingivitis and periodontitis that can cause tooth loss.

Principal will be offering extra cleanings and other services to pregnant dental plan members and those who suffer from heart disease and diabetes.

Recent studies have suggested that gum disease may cause premature labor, aggravate heart disease and interfere with control of blood sugar.