Histologic study of healing of human periodontal defects after placement of porous hydroxylapatite implants

Two intrabony pockets on teeth that were to be extracted for prosthetic reasons, in two patients, were treated by means of papilla preservation flaps and implantation with porous hydroxylapatite. The teeth, with a portion of their periodontium, were extracted 5 and 6 months after treatment and processed histologically. Both cases showed the implants invaded by connective tissue, which was actively forming bone. There was no inflammatory reaction triggered by the implant material, although there was some recurrence of inflammation in the vicinity of the pocket wall. The junctional epithelium in both cases extended slightly beyond the coronal level of the implant. One of the cases had an abundant new cementum formation with fibrous tissue next to the implant, that appeared to be a rebuilt attachment of collagen fibers. Although some multinucleated giant cells were found in the pores and next to the newly formed bone, the implanted material did not appear to be resorbed in the period of time studied.