Human Intraosseous Healing Responses to the Placement of Tricalcium Phosphate Ceramic Implants

Abstract

Five intrabony lesions in a 40-year-old healthy, white female patient suffering with severe periodontitis were removed en bloc, 13 to 18 months after flap debridement and graft placement. At the time of debridement, the position of the gingival margin and the most apically located calculus were notched in the root to serve as reference points. All lesions received tricalcium phosphate ceramic implants, and the lesions healed uneventfully. The sites were professionally cleaned frequently during the experimental period. At the time of block removal, clinical measurements demonstrated gingival recession (average = 2.6 mm) and a gain in clinical closure (average = 2.3 mm). Histological evaluation of step serial sections of these blocks showed limited presence of graft particles. The particles were surrounded by dense connective tissue. They did not induce inflammation, nor did they appear to enhance osteogenesis or cementogenesis. Closure of lesions was essentially done by a long junctional epithelium adhesion and limited evidence of new connective tissue-root attachment. In the 18-month specimen, active root resorption was seen immediately apical to the junctional epithelium at a site demonstrating significant inflammation in some sections. Fibrils apparently arising from the resorbing dentinal wall were seen in these sections. Serial sections of this site showed cellular cementum and functional fiber attachment at the resorption sites. These variations in resorption/repair/regeneration within the same surgical site were seen 18 months postsurgery and thus may reflect local tissue responses to inflammatory fluctuations rather than surgical sequellae.