Is estrogen deficiency a risk factor for periodontal disease?

In recent years, interest in the relationship between osteopenia, osteoporosis, estrogen status, and periodontal disease has grown considerably. A substantial number of studies have attempted to address this important question. Despite the large body of evidence, controversy persists concerning a possible association between these conditions. Whether loss of oral bone is related to loss of systemic bone and whether estrogen deficiency modulates loss of oral bone are subjects of more specific debate. This article reviews the direct and indirect scientific evidence supporting the role of estrogen deficiency as a risk factor for periodontal disease. A model is proposed for the biological basis of such increased risk. The article also suggests essential criteria for the design of studies examining the relationship between osteopenia, osteoporosis, estrogen deficiency, and periodontal disease.