Histologic evaluation of new attachment in humans. A preliminary report

This study was designed to evaluate the potential for regeneration of a new attachment (alveolar bone, cementum and a functional periodontal ligament) in patients whose attachment apparatus had been destroyed by periodontal disease. In each of the three parts of the investigation, the most apical level of calculus on the root served as a histologic reference point to measure regeneration. In Part I, attempts were made to initiate the formation of a new attachment by surgical debridement, crown removal (coronectomy) and submersion of the vital root below the mucosa. Nonsubmerged, surgically debrided defects served as controls. In Part II, debrided intrabony defects were treated with and without demineralized freeze-dried bone allograft and the associated vital roots were submerged. Part III evaluated potential for regeneration of a new attachment in nonsubmerged roots with and without the use of demineralized freeze-dried bone allograft. Gingival grafts were placed over the experimental and control sites in an attempt to retard epithelial migration. Biopsies were obtained in 6 months and regeneration was evaluated histometrically. Preliminary results in 7 patients and 24 intrabony defects indicate that new attachment is possible on pathologically exposed root surfaces in a submerged environment with and without the incorporation of demineralized freeze-dried bone allografts. New attachment was observed on pathologically exposed root surfaces in a nonsubmerged environment when intrabony defects were grafted with demineralized freeze-dried bone allograft. New attachment was not observed on nongrafted, nonsubmerged, defects with and without the placement of gingival grafts over the defects.