Bone formation with heparinized plastic implants in rats--a methodological study

A new model for studying periosteal bone formation was evaluated. Twenty-eight male Sprague-Dawley rats were anaesthetized, and heparinized plastic rings 3 millimetres in diameter were surgically inserted under the temporal muscle. The implants examined were one and two millimetres high. The bony surface of the implant area of every second rat was polished in order to remove all remnants of periosteum. The amount of bone formed in the centre of the implants was estimated after 14 and 28 days. Four rats acted as controls. The results suggest that bone formation follows a similar pattern regardless of the height of the implant, duration of the experiment and polishing of the bony surface. The model described was also found to be adequate for studying factors involved in periosteal bone formation.