Connective Tissue Response to Periodontal Dressings

The effects of three periodontal dressings (Coe-Pak, PPC, Perio Putty) upon subcutaneous tissues in 26 Sprague-Dawley rats were investigated. The three dressings, and a control (Teflon), were placed into polyethylene tubes. Two tubes per animal were implanted on either side of the dorsal midline area. After 14 days the specimens were retrieved and prepared for histological examination. Three methods of scoring were utilized for evaluation. First, a system evaluating the overall number of inflammatory cells, connective tissue capsule thickness, and the vascular changes produced; second, an inflammatory cell count, the Inflammatory Index (I.I.), computing the inflammatory cells in a particular field of view for each material; and third, a Reaction Spread Index (R.S.I.) comparing the distance of the spread of the inflammatory reaction into the connective tissues. Statistical analysis of the data was carried out utilizing the Chi-square test and analysis of variance. While the three scoring systems utilized did result in some comparative variation in reactions, the overall order of decreasing severity was always PPC, Coe-Pak, Perio Putty, and Teflon.