Bone pore volume of pores ranging from 0.1 to 77 mum in diameter was unchanged in alveolar bone from patients with periodontal disease compared with control subjects, a finding that is inconsistent with the involvement of systemic factors in alveolar bone loss in this disease. Bone density was decreased in alveolar bone from patients with periodontal disease. Bone density of normal alveolar bone increased with age. A similar finding was obtained in rat diaphyseal bone, suggesting that this is a general phenomenon in aging bone. This could be significant inasmuch as high density bone would be expected to be more brittle. In contrast to these findings in normal alveolar bone, bone density decreased rather than increased in the 50- to 59-year-old age group in patients with periodontal disease. The cause of decreased bone density remains to be established.
