Age factor in human alveolar bone repair.

This was a retrospective review study based on histological and histochemical observations of 69 biopsy specimens of human extraction wounds, screened for elimination of medical or nutritional disorders that might have interfered with normal healing. Initially, for the first 10 post-extraction days, tissues from the younger individuals (second decade or less) and those from older individuals (sixth decade or over) appeared to heal at the same rate. After 10 post-extraction days, the younger tissues continued with progressive healing and osteoid formation, while the older tissues remained in a resting (lag) phase. Following approximately three weeks, the older tissues entered into an accelerated growth cycle, and by 30 to 40 days equaled the healing pattern of the younger tissues, describing a sigma-type curve.