Various oral contraceptives appear to have differing effects on a woman's risk of developing gum disease -- the leading cause of tooth loss. A number of studies have suggested that sex hormones influence the progression of gum disease. At least one study has found that levels of gum disease-causing bacteria in a woman's mouth may increase after she begins using oral contraceptives.
Contraception 1998;57:381-384.
COMMENT: I believe that virtually all women should not take birth control pills. These synthetic hormones are fraught with multiple complications and we may only know the tip of the iceberg. They clearly increase the risk of breast cancer and now we find out that they can also increase your risk of gum disease and tooth decay.