[Tooth loss and osteoporosis].

In spite of promoting the 8020 campaign in Japan, the number of residual teeth is 4.6 at the age of 80. The dental loss in adult is caused mainly by caries and/or periodontal disease. Although both osteoporosis and periodontal disease show symptoms to bone tissue, the correlation between osteoporosis and periodontal disease still remains not so clear. Further studies are necessary to detail the mechanism of periodontal bone resorption influenced by not only local factors but also systemic condition of bone metabolism.