Western Society of Periodontics

Laboratory Studies

Volume Number 4, 1995

Periodontal regeneration in class III furcation defects of beagle dogs using guided tissue regeneration therapy with platelet-derived growth factor

The aim of this study was to evaluate the efficacy of periodontal repair and regeneration of class III furcation defects in the beagle dog, using GTR therapy alone and GTR therapy with platelet-derived growth factor (PDGF).The investigators, using six dogs, extracted mandibular P1 and P3 and scaled and root planed P2 and P4. Then they created class III defects, placed an orthodontic wire through the furcation, and closed the flaps for four weeks. The wires then were removed, roots were planed, and plaque was controlled with 2% chlorhexidine gluconate. The reconstructive therapy consisted of full-thickness flap elevation, thorough degranulation, and root planing. The root surfaces then were subjected to the following treatments: (1) conditioned with citric acid for three minutes, washed with saline and air dried, and treated with recombinant human PDGF-BB using a micropipette, after which a periodontal membrane was trimmed and fitted to the defect; and (2) conditioned with citric acid, treated with vehicle only, and a periodontal membrane placed around the tooth. The flaps were sutured in a coronal position that covered all but the cusp tips of the teeth. At 5, 8, and 11 weeks the animals were sacrificed and furcation areas sectioned and stained. The results revealed that at 5 weeks the two groups did not show any significant difference in the areas occupied by epithelium, inflamed tissue, and fibrous connective tissue. At 8 weeks the P-GTR group had complete healing while the GTR group still had unoccupied space and significant inflamed tissue. At 11 weeks the GTR group still had epithelium at the fornix of the furcation (4.3%) and inflamed tissue (9.4%).The histological examination revealed that the GTR therapy at 8 weeks had chronically inflamed tissue in the coronal one-third and there was no formation of bone and cementum, while the P-GTR therapy had nearly complete regeneration with bone and collagen fibers. At 11 weeks the GTR therapy still had the one-third coronal furcation occupied with epithelium and the apical two-thirds repaired with new bone and PDL. The P-GTR therapy revealed complete regeneration with a thin layer of new cementum, collagen fibers in an oblique fashion, and new alveolar bone. The authors conclude that P-GTR therapy effectively promoted periodontal regeneration without aberrations such as root resorption and ankylosis. [M.C.R.]