[Aspect of proliferous bony ingression into ceramic tube]

Ceramic materials have been clinically utilized as artificial biomaterials in the stomatognathic ffeld today. Among the materials bioinert alumina ceramics was selected in this study to investigate the fundamental aspect of bony ingression into porous ceramics and influence of pore diameter on the ingression. Tubes made of alumina ceramics of respective pore diameters of 200, 300 and 500 microns were embedded in the mandibular bones of rabbits, and the aspect was observed with the passage of time. The osseous area in the tube was measured through image analysis system of contact microradiogram (CMR) of cross sections and the following conclusions were obtained: 1. Bony ingression was observed in all the porous diameter in 2 weeks after the embedding, and increased during the subsequent period up to 6 months. The alumina ceramics used in this study showed high histological affinity. 2. The respective diameters of 200, 300 and 500 microns were suitable for the pore of the alumina ceramic tooth root materials. The embedding period without any burden was estimated to be better for 6 months. 3. The adequate pore diameters of porous alumina ceramics, when used as osseous prosthetic materials, were 200 and 300 microns, because in these cases new bones proliferated well into the tube up to the depth of 5mm.