Nifedipine-induced gingival hyperplasia: a clinical and in vitro study.

Two cases of gingival hyperplasia associated with long-term administration of nifedipine, a drug that dilates coronary arteries, are reported. The clinical and histopathological features of the gingival hyperplasia induced by nifedipine were similar to those induced by phenytoin, an anticonvulsant drug. In the present cases, gingival inflammation had developed before drug administration. In one case, extensive dental plaque control in addition to surgical removal of the overgrown gingival tissues resulted in satisfactory progress without the need to discontinue drug administration, suggesting that the preexisting gingival inflammation was involved in the development of this periodontal disease. In the other case, change from nifedipine to another drug resulted in spontaneous recovery, strongly suggesting that the drug had induced the gingival hyperplasia. Nifedipine had no direct effects in vitro on proliferation or collagen synthesis of gingival fibroblastic cells from one of the patients. Study of these two cases suggests that both local inflammatory factors and long-term administration of nifedipine were responsible for the gingival hyperplastic changes observed.