Periodontal regeneration of human intrabony defects. IV. Determinants of healing response.

The purpose of this study was to identify factors which might affect the healing response in intrabony defects treated with guided tissue regeneration. Selected sites presented with deep periodontal lesions with 1, 2, and 3 wall combination intrabony component of 6.1 +/- 2.5 mm. The significance of patient, tooth, and defect characteristics and surgical parameters as predictor variables affecting the regenerative outcome before and following the removal of the barrier membrane was assessed. Outcome was measured as tissue gain under the membrane, regenerated probing attachment level (PAL), and bone fill. The total depth of the intrabony component and the radiographic defect angle significantly affected the amount of tissue gain. Seventy-five percent (75%) of the variability of regenerated PAL and bone fill was explained in terms of tissue gain under the membrane, radiographic width of the defect angle, full mouth bleeding score, and presence or absence of flap coverage of the newly formed tissue. Control of the identified predictor variables might improve the extent and predictability of guided tissue regeneration in the treatment of deep intrabony defects.