Guided tissue regeneration with dentin biomodification.

This study was undertaken to provide histologic observations on the effectiveness of citric acid and tetracycline HCl root surface demineralization when used in conjunction with guided tissue regeneration (GTR) procedures. Eight beagle dogs with naturally-occurring periodontitis were initially treated with scaling and root planing. Four weeks later, 12 mandibular quadrants were treated surgically with modified Widman flap and expanded polytetrafluoroethylene (ePTFE). The teeth in 4 of the quadrants were randomly root conditioned with tetracycline HCl, while those in 4 additional quadrants were randomly treated with citric acid. ePTFE membranes were sutured in place. The beagles received prophylaxis (chlorhexidine and toothbrushing) 3 times a week. After 6 weeks, the membranes were removed; prophylaxes continued for 4 months. Histological evaluation revealed new cementum on the root surfaces. A new periodontal ligament with fibers inserting into the new cementum was noted. Statistical evaluation of the buccolingual measurements demonstrated membranes alone resulted in significantly more new connective tissue and new bone formation than membranes with root conditioning agents. Within the furcation, no significant differences were found. However, there was a trend for more bone formation with membranes alone. Within the limits of this study it may be concluded that GTR utilizing an ePTFE membrane results in new connective tissue attachment and bone regeneration in the beagle dog. Root surface demineralization with citric acid or tetracycline HCl does not enhance the results achieved with GTR when used alone.