抄録
Extraction sockets of the dog were examined tridimensionally with a scanning electron microscope in order to clarify the process of blood clots transform action into bone in osseous repair. Excellent observation was able to be made only when total perfusion of the head-neck and cracking with styrene resin were utilized.
On postextraction days 1-2, sockets were filled with clots of red blood cells and fibrin networks. By the second day, fine fibrils of 0.1 μm in diameter had appeared, twisting around fibrins and rapidly increasing in amount. Collagen fibers of 0.4-0.6 pm in diameter which started to appear on the 4 th day, became predominant and replaced the former fine fibrils by the 7 th day, by which time the original clots had been completely transformed into fibrous tissue masses. In addition, on the 7 th day, osteoblasts began to appear in this sea of collagns. Apposition of calcospherites were also observed on some collagen fibers near these osteoblasts. Between the 14 th and 21 st day after extraction, calcospherites measuring 0.3-0.5 pm in diameter gradually filled the intercollagenous spaces to form the bony matrix. X-ray microanalysis of these calcospherites confirmed the presence of calcium and phosphorus. By postextraction day 30-60, well-formed lamellar bony trabeculae with Haversian systems had appeated, and this completed osseous repair of the socket.
