Tunnel technique and subepithelial connective tissue graft, with or without cross-linked hyaluronic acid, in the treatment of multiple gingival recessions: 12-month outcomes of a randomized clinical trial.

Background: This study evaluated the influence of the adjunctive application of a cross-linked hyaluronic acid (HA) in the treatment of multiple gingival recessions, using a modified coronally advanced tunnel (MCAT) technique and subepithelial connective tissue graft (SCTG) (MCAT+SCTG±HA).

Methods: A randomized, split-mouth, double-masked comparison of the effects of MCAT+HA+SCTG (test) versus MCAT+SCTG (control) in the treatment of multiple, contralateral gingival recessions with clinical, esthetic, and histological evaluations was carried out. All samples were stained with hematoxylin and eosin, Masson's trichrome, Verhoeff-Van Gieson, and Alcian blue stain for semiquantitative evaluation. The primary outcome variable was 12-month mean root coverage (MRC).

Results: Twenty-four patients with 266 gingival recessions received both control and test treatments (133 recessions per group). 12-month MRC of the MCAT+HA+SCTG group was not significantly different from the MCAT+SCTG group with 84.32%±  34.46% and 85.71%±  36.43%, respectively (p = 0.991). Both treatment modes produced favorable esthetic outcomes (root coverage esthetic score [RES] 9.51±  1.01 tests vs. 9.26±  1.10 controls, p = 0.7292). However, the application of HA improved soft tissue texture (p = 0.0091). The remaining end point measures did not differ significantly between groups. Histological evaluation showed a significantly greater number of elastic fibers and a moderate increase in collagen fiber density in biopsy samples taken from the test sides when compared to the control sides (p = 0.0419 and p = 0.300, respectively).

Conclusions: MCAT+SCTG is an effective procedure in the treatment of multiple recession Type 1 (RT1) and RT2 recessions. There were no statistically significant differences in evaluated clinical treatment outcomes in the MCAT+HA+SCTG group compared to the MCAT+SCTG group within a period of 12 months. The application of HA increased collagen and elastic fiber density.