Despite the advantages of connective tissue transplantation for gingival recession, the scarcity of grafts and the need for a secondary surgical site limit its utility. Consequently, guided tissue regeneration (GTR) using allograft membranes has been employed, showing promising results. Human placental membranes, like amnion and chorion, have been used successfully in medicine for healing burns and ulcerated skin disorders, owing to their unique biological properties that promote wound healing and may encourage regeneration. These membranes also have anti-adhesive effects, are bacteriostatic, provide wound protection, reduce pain, and aid epithelialization, making them suitable for GTR in dental applications. This study aimed to compare the efficacy of modified coronally advanced flaps (MCAF) and tunneled coronally advanced flaps (TCAF), both combined with amnion membrane, in treating gingival recessions.

A parallel-mouth randomized controlled trial was conducted with ten patients (five men and five women) aged between 38 and 45, presenting with 34 gingival recession defects. Participants were randomly assigned to either the test group (TCAF) or the control group (MCAF), each consisting of five patients. The test group underwent the tunneled coronally advanced flap procedure with an amnion membrane for treating RT1 and RT2 gingival recessions, while the control group underwent the modified coronally advanced flap technique with an amnion membrane for similar conditions. Inclusion criteria required patients to be 18 years or older, have esthetic concerns or hypersensitivity due to gingival recession, and be systemically healthy. Exclusion criteria included uncontrolled systemic diseases, smoking, active periodontal disease, medications affecting soft tissue healing, allergies to the biomaterials used, and pregnancy or lactation.

Patients received nonsurgical therapy, including scaling and root planing, followed by oral hygiene instructions. Clinical parameters such as probing depth (PPD), gingival recession width (GRW), width of keratinized tissue (WKT), and gingival tissue (GT) were measured at baseline and six months by a masked examiner. A "root coverage esthetic score" (RES) was used to evaluate aesthetic outcomes. For the surgical procedures, the control group underwent a split-full-split thickness flap without vertical releasing incisions, and the amnion membrane was placed over the root surfaces before advancing the flap coronally. The test group involved a vertical incision, creation of a split-full-split thickness flap, and tunneling to place the amnion membrane within the flap, secured with sutures.

Post-surgical care included prescribing antibiotics and using chlorhexidine mouthwash, with oral hygiene instructions and suture removal after 14 days. Clinical indicators were re-measured at three and six months, and patient satisfaction was assessed using the visual analogue scale (VAS) at baseline and six months. Statistical analysis, conducted using SPSS software, involved paired t-tests for intragroup comparisons and unpaired t-tests for intergroup comparisons.