The effect of root planing and citric acid applications on flap healing in humans. A histologic evaluation

Four human teeth and their facial gingival attachment were removed en block 3 months after periodontal flap therapy and citric acid root conditioning and then prepared for histologic evaluation. At the time of periodontal surgery, and prior to citric acid application, the facial root surface was grooved at midline and citric acid was applied only to one-half of each root surface. Tissues were decalcified and histologically prepared as horizontally oriented, step serial sections from the level of the gingival margin to the level of the facial crest. The gingival margins demonstrated reformation of a crevice. The corium at this level showed a mild inflammatory infiltrate. Apical to this level, junctional epithelium adhered to both sides of the root surface and to the central groove. Further apically, supracrestal fiber groups were encountered. No new cementum was noted in these areas. Fiber attachment was present apical to this level. Since no new cementum was seen at this area of attachment, it may represent collagen attachment present prior to periodontal surgery. In the four specimens examined, no differences were seen in the soft tissue closures between the root-planed citric acid-treated root surfaces and root surfaces which received root planing alone.