Abstract
Bone formation and microvascular changes after implantation of bio-active (glassceramic) and bio-inert (alumina-ceramic) materials were studied chronologically by LM, TEMand SEM of corrosion casts.
The results were summarized as follows:
1. In the early stage, bone formation was observed directly on the glass-ceramic and densevascular network was found on the interface of the implant. In case of the alumina-ceramic, however, coarse vascular network was found among the newly-formed bone trabeculae.
2. At 4 weeks, the bone on the glass-ceramic became to connect with the surrounding bone.In case of the alumina-ceramic, two types of areas were observed; one was active bone formationarea and the other was active bone resorption area. Therefore, after 4 weeks was thought to be animportant stage which would influence the condition of the surface of the implant.
3. At 8 weeks, bone was formed on most part of the glass-ceramic. Multinucleated giantcells (MNGCs) having ruffled border were recognized in the area where bone was not formed. These MNGCs were thought to relate the bone remodelling on the surface of the implants. Onthe other hand, alumina-ceramic was covered with bone or fibrous tissue, and no active boneremodelling was observed.
