Postmenopausal estrogen replacement and tooth retention.

PURPOSE: To determine if estrogen replacement therapy (ERT) is associated with improved tooth retention and lower risk of edentulism (no natural teeth remaining) in a cohort of elderly women. PATIENTS AND METHODS: Subjects were 488 women, aged 72 to 95, who participated in the 23rd examination cycle (1994 to 1995) of the Framingham Heart Study, a population-based study begun in 1948. The number of teeth remaining and their location were recorded by a trained observer. History and duration of ERT were obtained from records kept since cycle 10 (1960 to 1963). Third molars were excluded from all analyses.
RESULTS: Women who ever used ERT were younger than nonusers by 1 year (80 +/- 4 years, n = 184, versus 81 +/- 4 years, n = 304, P = 0.019). Estrogen users had more teeth remaining than nonusers (12.5 +/- 0.8 versus 10.7 +/- 0.8 versus 10.7 +/- 0.6 teeth, P = 0.046, mean +/- SE) after controlling for age, smoking status, and education. Duration of estrogen use was an independent predictor of the number of teeth remaining (P = 0.015) such that each 4.2-year interval of use was associated with an increased mean retention of 1 tooth. Long-term estrogen users (more than 8 years, n = 48) had an average of 3.6 more teeth than women who never used estrogen (14.3 +/- 1.5 versus 10.7 +/- 0.6 teeth, P < 0.02). The association with duration of use was present among different types of teeth (incisors, canines, and premolars) but less strong for molars. The odds of being edentulous were reduced by 6% for each 1-year increase in duration of estrogen use (odds ratio = 0.94, P = 0.038, 95% confidence interval = 0.90 to 0.99).
CONCLUSIONS: These data suggest that ERT protects against tooth loss and reduces the risk of edentulism. The associations of estrogen use and tooth retention are evident for all but the molars.