Treatment of osseous defects with fibroblast-coated hydroxylapatite particles

Several techniques of periodontal regeneration have been used, including hydroxylapatite (HA) grafting, demineralized free-dried bone allografts and guided tissue membranes, for which clinical merits still need further scientific study. The purpose of this pilot study was to examine the healing of periodontal defects using HA grafts coated with fibroblasts isolated from the periodontal ligament (PDL). We cultured fibroblast-like cells either from a clinically healthy site of the PDL or gingival tissues of the subject receiving the cell transplantation. We added HA to the cultures and allowed the cells to migrate onto the HA surface. Then the HA particles coated with cells were harvested and transplanted into the periodontal osseous defects of four patients after phase I treatment. Three HA grafts without coating cells were used as controls. Periapical x-ray and clinical parameters were monitored for up to six months. Scanning electron microscopy demonstrated that fibroblast-like cells had proliferated on the HA particles in vitro. Our results showed that the experimental group had greater pocket reduction and clinical attachment gain, and less gingival recession than did the control group at six months postoperatively. Periapical films revealed good filling of osseous defects in both groups. This study introduces a new biological approach for bringing PDL cells into intimate contact with root surfaces, in order to facilitate earlier repopulation of root surfaces with regenerative PDL cells.