TODA Isumi Osaka Dental University, Faculty of Dentistry, Assistant, 助手 (20197891)
OKADA Shigenori Osaka Dental Univetsity, Faculty of Dentistry, Assistant, 助手 (30160675)
SUWA Fumihiko Osaka Dental University, Faculty of Dentistry, Lecturer, 講師 (30067178)
OKUDA Hitoshi Osaka Dental University, Faculty of Dentistry, Assistant Pro., 助教授 (70067148)
|Budget Amount *help
¥6,300,000 (Direct Cost : ¥6,300,000)
Fiscal Year 1991 : ¥1,700,000 (Direct Cost : ¥1,700,000)
Fiscal Year 1990 : ¥4,600,000 (Direct Cost : ¥4,600,000)
In other to elucidate bio-compatibility of the dental materials, successive changes of the microvascular architecture which contributes to form supporting tissues, especially bone tissue, have been investigated utilizing the acryl plastic injection method (Ohta et al., 1952, 1955, 1990) for a scanning electron microscopy.
Materials and methods : Implant operations were performed by the primary, secondary and immediate procedures on the upper incisor and lower molar regions of Japanese monkeys. Implant materials used for this study were titanium, hydroxyapatite (HAP), HAP・alumina-coated Ti (cylinder, blade-vent), alumina-ceramics (notched, pored, blade), etc. Three-dimensional specimens mounted with both microvascular corrosions and bone tissue, and histological slides, were prepared ranging from immediate to 10 weeks after implantation and examined under a scanning electron microscope (JEOL JSM- T300).
Results : Generally, an initial extension of newly formed sinusoidal capillaries was f
ound on the implantal interface two weeks after implantation. Each of new bone tissues appearing in the shape of an island have developed to a wide plate up to four weeks. Outside it a capillary cylinder was located between the preexistant and newly formed bones. However, when a perimplantal space was exsistant, a characteristic bone trabeculae spread from the preexistant bone with newly-formed sinusoids and proliferated to complete a final osseous integration. On the HAP interface, a new bone tissue appears in a peculiar form (ankylosis) differing from the above trabeculae. A pore of the alumina ceramics has been invaded by a new sinusoidal capillary two weeks but scarcely filled up all pores yet. It can be concluded that periods of two to four weeks after implantation are an important and significant to form a newly-formed woven bone, the beginning of which is found at a limited area of the implant interface, such as notch, screw and vent, always accompanying with the sinusoidal capillary. For the present, influences on surrounding structures of the already-fixed implant have continuously investigated under various occlusal conditions. Less