Tunnel technique with connective tissue graft versus coronally advanced flap with enamel matrix derivate for root coverage: 2-year results of an RCT using 3D digital measuring for volumetric comparison of gingival dimensions.

Abstract

The aim of this randomized clinical trial was to compare clinical and volumetric outcomes of tunnel technique (TUN) with subepithelial connective tissue graft (CTG) versus coronally advanced flap (CAF) with enamel matrix derivate (EMD) 2years after gingival recession (GR) treatment. Twenty-three patients contributed 45 Miller class I or II GR. At baseline and follow-up examinations, study models were collected. Their three-dimensional scans allowed precise computer-assisted measurement of recession depth (REC), complete root coverage (CRC), percentage of root coverage (RC), pointwise (pTHK) and mean areal (aTHK) marginal soft tissue thickness. Clinical examination delivered probing depths (PPD) and height of keratinized tissue. 24months after surgery, digitally evaluated CRC was present in 60.0% of the TUN+CTG and 0.0% of the CAF+EMD-treated sites (p<.0001), meaning a certain relapse of the gingival margin ragarding both approaches. RC amounted to 94.0% (TUN+CTG) and 57.3% (CAF+EMD), respectively (p<.0001). REC reduction (RECred) was significantly higher for TUN+CTG (1.81±0.56mm) than for CAF+EMD (0.90±0.45mm) (p<.0001). pTHK and aTHK values were significantly greater in the TUN+CTG group (1.41±0.35mm and 1.11±0.26mm) than in the CAF+EMD group (0.78±0.32mm and 0.60±0.26mm) (p<.0001). Statistical analysis detected positive correlations between THK and both RC and RECred (p<.001). Two years post-operatively, CTG showed better clinical and volumetric outcomes than EMD. Increased THK values were associated with improved outcomes regarding RC and RECred.