[Effects of pregnancy, lactation and dietary calcium on alveolar bone loss].

Periodontitis is a local inflammatory disease mainly induced by periodontopathic bacteria including Porphyromonas gingivalis. This disease is characterized by the destruction of periodontal tissues including alveolar bone, which is accelerated by various local and systemic factors. In recent years, many investigators focused on the relationships between periodontitis and systemic diseases such as diabetes and osteoporosis. We are currently studying the effects of pregnancy, lactation and dietary calcium on the bone mineral density of rat alveolus. The results obtained so far showed that pregnancy and subsequent lactation decreased the bone mineral density, and could be the risk factors for alveolar bone loss, especially under the condition of Ca insufficiency or deficiency. Further studies are required to define the relationships between periodontitis and systemic diseases affecting bone metabolism.