Clinical comparison of the free soft tissue autograft and partial thickness apically positioned flap--preoperative gingival or mucosal margins.

Apically positioned split thickness flaps were performed at two selected sites in each of 10 patients. Equivalent amounts of periosteum were left exposed to standardize the method. In five patients the preoperative dentogingival margins consisted of gingiva, whereas in the five others a margin of alveolar mucosa was present. In all patients the pre-existing margin was sutured apically to periosteum, after reflection of the split thickness flap. At one surgical site in each patient a free soft tissue autograft, donated from the palate, was sutured to the periosteum left exposed coronal to the apically positioned flap margin. The second surgical site was left not covered by any biological dressing. Measurements from three fixed reference points on a stable acrylic device were recorded preoperatively and at 2, 4, 6, 8 and 12 weeks postoperatively. The graft and split thickness flap procedures were then biometrically compared by application of the Null Hypothesis and t test for the difference of the means to determine any significant differences. It was concluded that the presence of a preoperative dentogingival margin of gingiva suggested that either the free graft or split flap procedure would eliminate pockets extending beyond the mucogingival junction, and would establish adequate zones of attached gingiva without deformity at the dentogingival junction. However, the presence of a preoperative margin of alveolar mucosa suggested the use of the free soft tissue autograft to attain the above. The thickness of connective tissue afforded by a preoperative margin of gingiva was assumed to be the responsible factor for the above conclusions.