New attachment achieved by guided tissue regeneration in beagle dogs.

This study tested the effects of using a Gore-Tex periodontal material on new connective tissue attachment in beagle dogs with natural periodontitis. Seven female beagle dogs with advanced periodontitis were selected and given thorough root debridement. Under general anesthesia four weeks later, mucoperiosteal flaps were raised involving all mandibular premolars and first molars. Gore-Tex periodontal material was adapted to all premolars, and the flaps were sutured tightly, keeping the material covered. The first molars acted as controls, receiving only surgery. Some material was removed in one month, while other materials were removed eight to 10 weeks after surgery. All dogs were sacrificed at three months. After processing, descriptive histology and histometrics were carried out, evaluating new connective tissue attachment, bone response and epithelial downgrowth. Results were statistically analyzed, using paired t tests. They showed new connective tissue attachment with cementum deposition in areas where the material was used. Also, the epithelial downgrowth was reduced in these areas. In the controls, minimal connective tissue attachment was found, with the area healing by a long junctional epithelium. Statistical analysis showed significant differences (P less than 0.05) favoring experimental areas both in the increase of new connective tissue attachment and in the decrease of epithelial downgrowth. No differences were found between areas where the material was removed in one month or left longer in place. No difference in bone response was found. Gore-Tex material was effective in blocking gingival epithelial downgrowth and connective tissue proliferation, promoting new attachment according to the principle of "guided tissue regeneration."