The effect of different treatment modalities on connective tissue attachment

This study compared the effect of four treatment modalities on connective tissue attachment. Ligature-induced periodontitis was established around the mandibular premolars of five young beagle dogs over 8 weeks. Following a 2-week period without ligatures, a reference dog was sacrificed to estimate the extent and nature of the disease. Three dogs received flap procedures in one mandibular posterior segment, and the six experimental roots were treated with citric acid (pH 1) for 3 minutes; the contralateral mandibular segments received flap procedures and the roots were treated with 4% chlorhexidine gluconate in the Hibiclens preparation for 3 minutes. One segment of the control dog received flap procedures, and the roots were treated with sterile normal saline; the contralateral segment received closed root planning. The experimental dogs were sacrificed 1, 2 and 3 months after treatment. The control dog was sacrificed 3 months postoperatively. One week before sacrifice each dog received a Procion dye injection. At sacrifice the study segments of all four treated dogs were clinically healthy, with no observable differences between the different treatment modalities. Histologically, the 1, and 3-month chlorhexidine, the 3-month saline and 3-month root planed specimens had long junctional epithelial adhesions with little connective tissue attachment. The 2-month chlorhexidine and all citric acid-treated sections showed appreciable amounts of new connective tissue attachment. Some 2-month and 3-month citric acid and 2-month chlorhexidine sections showed cementum over the apical portion of the long junctional epithelium. The frequency of occurrence and the length of cementum overlapping epithelium increased appreciably over time.(ABSTRACT TRUNCATED AT 250 WORDS)