Significance of the epithelial collar on the subepithelial connective tissue graft.

Background: Most clinicians adopt two versions of the subepithelial connective tissue graft (SCTG) procedure, SCTG with or without the epithelial collar on the graft combined with a coronally advanced flap (CAF). However, limited evidence is available to determine whether a retained epithelial collar on an SCTG is needed for a better outcome. The goal of this study was to compare the clinical outcomes of the two SCTG techniques (i.e., SCTG with or without an epithelial collar).

Methods: Twenty patients with Miller Class I or II gingival defects >/=2.0 mm were recruited for the study. The patients were randomly assigned to receive an SCTG with a retained epithelial collar + CAF (SCTGE; n = 10) or an SCTG without an epithelial collar + CAF (SCTGN; n = 10). Clinical parameters, including recession depth, recession width (RW), width of keratinized gingiva (KW), clinical attachment level (CAL), probing depth (PD), gingival index (GI), and plaque index (PI), were assessed at baseline and 3 and 6 months after surgery.

Results: SCTGE and SCTGN groups exhibited significant root coverage at 3 and 6 months compared to baseline (P <0.05). The SCTGE group had mean root coverage of 97.50% +/- 7.90% at 6 months compared to 89.10% +/- 25.93% in the SCTGN group, with no significant difference between the groups. At 6 months, complete root coverage was seen in nine of 10 and seven of 10 subjects from SCTGE and SCTGN groups, respectively. Mean KW at 3 months for the SCTGE group was 4.10 +/- 1.10 mm, whereas in the SCTGN group it was 2.75 +/- 0.68 mm. Mean RW was 0 mm and 1.20 +/- 1.60 mm for SCTGE and SCTGN groups, respectively. KW and RW were statistically significantly different between the two groups at 3 months; however, this significance was not seen at 6 months. Other clinical parameters (CAL, PD, thickness of the recipient gingival tissue, PI, GI, and the wound healing index) showed no significant differences between the groups at any time point.

Conclusions: Both SCTG techniques (with or without the epithelial collar) provided predictable and successful root coverage (>/=89%). This study suggests that a retained epithelial collar on the SCTG may not provide a significant benefit with regard to clinical parameters.