For making the apatite implant easy to use clinically and for having the apatite steadily exhibit its bony-ankylotic characteristic, the 2-piece apatite implant system consisting of the root portion, and the abutment portion was developed. The tissue compatibil ity of the root portion as the result of the first stage of the fundamental study of the 2-piec eapatite implant was already reported. Recently, in order to examine the tissue compatibility of the 2-piece apatite implant system in the mass after the cementation of the abutment portion and th e tissue around the 2-piece apatite implant under a functoinal load, with the 2-piece apatite i mplants placed in the lower jaw of adult dogs, the tissue around the implant was histologically o bserved one month after cementing the abutment portion and three and six months after cementing a superstructure.
Results:
1. The root portion in the jaw bone was in ankylotic bone with bone in almost all the parts, in the mucosa around the abutment portion, the inner epithelium was in close co ntact with the abutment portion and, in deeper layers than the inner epithelium, dense fibrous connective tissue covered the abutment portion, thus indicating a good tissue compatibility of th e 2-piece apatite implant.
2. Th e placement of the 2-piece apatite implant under a functional load caused no pr oblems around the implant, or rather the bone holding the implant indicated such pheno mena as thickening and compaction in order to adapt itself to the function.
3. 1 and 2 above revealed that the 2-piece apatite implant technique has no fundamental problems.
