Accelerated reattachment with cementogenesis to dentin, demineralized in situ. II. Defect repair.

Three surgical experiments, with histologic evaluation, were performed to study induced gingival reattachment to tooth root dentin demineralized in situ during flap surgery in adult mongrel dogs. Experiments demonstrated aspects of: (1) Weekly histochemical and morphological sequences of repair; (2) Repair of chronically inflamed bony defects simulating periodontal pockets; and (3) Six and 12 month repair of reattached surgical defects. Flap reattachment with cementogenesis was induced by in situ root demineralization using citric acid at pH 1.0 applied for 2 minutes. Results demonstrate: (1) The production of anchoring cementum pins extending into dentin tubules widened by demineralization; (2) Reattachment with cementogenesis of inflamed gingiva to roots exposed to chronically-infected surgical defects for 3 months; (3) Success in repairing chronic interproximal one-walled and labial one surface defects by reattachment; (4) Relative failure to repair bifurcation and horizontal bone defects by flap reattachment; and (5) Complete alveolar bone repair over most labial defects by 1 year, with maintenance of a periodontal ligament between induced bone and cementum. These findings, together with previous reports of induced reattachment to demineralized roots, provide further evidence for mechanisms and consistency and suggest that this regenerative phenomenon may be useful in repairing osseous defects in periodontal therapy.