Platelet-rich plasma and connective tissue grafts in the treatment of gingival recessions: A histometric study in dogs

Background: The aim of this study was to histometrically evaluate the healing process of gingival recessions treated with platelet-rich plasma (PRP) in combination with a subepithelial connective tissue graft (SCTG) and to compare it to that obtained with SCTG alone. Methods: Six mongrel dogs were used in the experiment. Gingival recessions (5 x 7 mm) were surgically created and exposed to plaque accumulation for I month. Contralateral defects were randomly assigned to the test group (SCTG + PRP) or the control group (SCTG). Dogs were sacrificed 45 days after the surgeries, and the blocks containing the experimental specimens were processed for histologic analysis. The histometric parameters evaluated were length of sulcular and junctional epithelium, connective tissue adaptation, new cementum, new bone, and defect extension. Results: A greater length of new cementum was observed in the sites treated with PRP (2.18 +/- 0.78 mm) compared to the control group (1.19 +/- 0.62 mm) (P <= 0.05). No statistically significant differences were observed in the remaining parameters. The extension of total epithelium (sulcular and junctional epithelium) was 2.04 +/- 0.57 mm for the test group and 2.49 +/- 0.82 mm for the control group. The new connective tissue adjacent to the root-without cementum formation was 0.29 +/- 0.28 mm and 0.23 +/- 0.18 mm for the test and control groups, respectively. Bone position was -0.57 +/- 0.95 mm for the test group and -0.46 +/- 1.34 mm for the control group. Conclusion: Within the limits of this study, the combination of PRP with SCTG was more effective in promoting new cementum formation than the graft alone.