Healing of localized gingival recessions treated with coronally advanced flap alone or combined with either a resorbable collagen matrix or subepithelial connective tissue graft. A preclinical study

To histologically evaluate the effectiveness of a porcine derived collagen matrix (CM) and a subepithelial connective tissue graft (CTG) for coverage of localized gingival recessions. Chronic single Miller Class I-like recessions were created at the buccal at the canines and at the third and fourth premolars in the upper and lower jaws of six beagle dogs. The defects were randomly treated with (1) coronally advanced flap surgery (CAF) + CM, (2) CAF + CTG, or (3) CAF alone. At 12 weeks, histometric measurements were made, e.g., between a reference point (N) - and the gingival margin (GM) - and the outer contour of the adjacent soft tissue (gingival thickness [GT]). The postoperative healing was uneventful in all animals. No complications such as allergic reactions, abscesses or infections were noted throughout the entire study period. All three treatments resulted in coverage of localized gingival recessions. The histological analysis failed to identify any residues of CM or CTG. The histometric measurements revealed comparable outcomes for N-GM and GT values for all three groups (CAF + CM: 1.04 +/- 0.69 mm/0.68 +/- 0.33 mm; CAF + CTG: 1.15 +/- 1.12 mm/0.76 +/- 0.37 mm; CAF: 1.43 +/- 0.45 mm/0.79 +/- 0.24 mm). In the used defect model, the application of CTG or CM in conjunction with CAF did not have an advantage over the use of CAF alone. The use of CAF alone is a valuable option for the treatment localized Miller Class I recessions.