A clinical evaluation of hydroxyapatite cement in the treatment of Class III furcation defects

Background: Calcium hydroxyapatite cement (HAC) has been demonstrated in bo th animal models and human craniofacial defects to be safe, absorbable, ost eoconductive, and possibly osteoinductive. This pilot study evaluated a nov el technique using HAC to surgically obturate Class III mandibular molar fu rcation defects. Methods: Following flap reflection, affected teeth in 6 patients were root planed and etched with citric acid. Experimental sites were grafted with HA C and coronally positioned flaps (CPF), while controls were treated by CPF only. A variety of clinical parameters were recorded initially, and at re-e ntry surgery 9 months later. Results: At re-entry, all experimental sites exhibited granulation tissue i nterposed between the HAC and the alveolar bone, and clinical findings were unsatisfactory. Mean probing depth, clinical attachment loss, and recessio n increased by 0.8 mm, 1.9 mm, and 1.2 mm, respectively, in experimental si tes. In controls, mean probing depth decreased by 0.8 mm, and clinical atta chment loss and recession increased by 0.3 mm and 1.2 mm, respectively. The re was a mean 1.6 mm loss in osseous crest height and a mean 2.2 mm worseni ng in osseous defect depth for experimental sites, but only a 0.5 mm loss i n osseous crest and 0.5 mm increase in osseous defect depth in control site s. Conclusions: Experimental sites lost 1.0 to 1.5 mm in bone and attachment c ompared to controls, without any significant clinical benefit. While the co ncept of surgically obturating Class III furcation defects with a safe, ost eoconductive material remains attractive, HAC did not promote repair or reg eneration in this technique.