Changes in Bone and Vasculature around Plastic Crown Implants

Objectives: This study was conducted to investigate successive changes in bone and blood vessel of an anode TiO2 implant circumference due to masticatory function. Methods: Implants placed in the lower jaw posterior teeth of 3 Japanese macaques were kept nonfunctional for 12 weeks (W) before the plastic crown (PC) was fixed. Experimental animals were euthanized after every 1, 4, 8 and 12 W. Microvasculature corrosion cast specimens obtained using acrylic resin injection methods were observed by SEM. Results: At the post 1 W PC mounting, very thin implantal alveolar bone (IAB) at the implant circumference was supported by a few travecular bones (TB). As time passed, IAB increased and thickened. Especially at 4-8 W, the TB was mainly formed, and at 12 W it was arranged, thickened and tabular. Although the microvasculature grew in the initial PC mounting stage, and was arranged with the formation of TB and IAB, then the blood vessels gradually decreased. Conclusions: Vigorous bone-growth stage was initiated 4-8 W after the PC mounting, bone tissue was stimulated by biomechanical stress, IAB thickened, and TB became thick and tabular. (The Ministry of Education, Science, Sports and Culture Grant-in-Aid No. 10671853, JAPAN)