The Tunnel Technique and Free Gingival Graft in Gingival Recessions Treatment

The present study aims to compare the tunnel technique/laterally closed tunnel technique and the FGG technique in the treatment of isolate/multiple GR in the anterior region of the mandible. Furthermore, it is proposed to evaluate the effect of a gel based on hyaluronic acid and green tea on the healing of the donor area after the removal of FGG from the palate. This work is expected to contribute to the still uncertain literature on the effectiveness of the tunnel technique as an alternative to the use of FGG in the treatment of multiple GR in the mandible.

Free gingival graft (FGG) is a simple technique considered the most effective procedure to obtain gingival augmentation in sites with a minimal amount of keratinized gingiva. However, the abscence of chromatic integration and unsatisfactory texture of the graft after healing prevent its use in areas with high aesthetic demand. In this context, the tunnel technique (multiple gingival recessions \[GR\]) and the laterally closed tunnel technique (isolated GRs in the mandible) have been proposed as an alternative to the use of FGG in the treatment of GRs in the mandible. The present study aims to compare the tunnel technique/laterally closed tunnel technique and the FGG technique in the treatment of isolate/multiple GR in the anterior region of the mandible. Furthermore, it is proposed to evaluate the effect of a gel based on hyaluronic acid and green tea on the healing of the donor area after the removal of FGG from the palate. Sixty participants presenting isolate/multiple Miller Class I, II, or III GR \[Recession type (RT) 1 or RT2\] in the anterior region of the mandible will be included in the present study. Regarding the treatment of GR, participants will be divided into four groups: (1) Test Group 1 (T1) (n=15): multiple GR in the anterior region of the mandible treated with the tunnel technique; (2) Test Group 2 (T2) (n=15): isolate GR in the anterior region of the mandible treated with the laterally closed tunnel technique; (3) Control Group 1 (C1) (n=15): multiple GRs in the anterior region of the mandible will be treated using the FGG technique and (4) Control Group 2 (C2) (n=15): isolate GRs in the anterior region of the mandible will be treated using the FGG technique. Regarding the treatment of the donor area, the same participants will be divided into two groups: (1) Gel Group (G) (n=30): the donor area on the palate will be treated using hyaluronic acid gel and green tea applied by the participant 3 times a day for 7 days; (2) Clot Group (CO) (n=30): No material will be placed in the donor area, only the clot will be kept in position by means of sutures. Periodontal clinical parameters will be evaluated in the receiving area at the beginning of the study and after 1, 3, 6 and 12 months postoperatively. In the donor area, the percentage of wound closure, the epithelialized surface area and the color of the palatine mucosa will be evaluated in both groups after 3, 7, 15 and 30 days. The visual analogue scale (VAS) of pain (donor and recipient area) and aesthetic (recipient area) will be used to assess the participant's perception of the treatment used.

Eligibility Criteria:
Inclusion Criteria:

* Age between 18 and 60 years old;
* Present isolated (≥4mm) or multiple GR in the anterior region of the mandible (tooth 33 to 43) Miller Class I, II or III (87) (or Recession type (RT) 1 or RT2);
* Systemically healthy with no contraindications for periodontal surgery;
* Probing depth of less than 3mm at the sites involved;
* Selected teeth properly positioned, free from endodontic treatment, any type of restorative treatment, caries or non-carious cervical lesion

Exclusion Criteria:

* Participants who use tobacco or other types of drugs;
* Participants submitted to periodontal treatment in the last 6 months;
* Pregnant participants;
* Participants who did not accept to return to follow-ups;
* Participants who used antibiotics, corticosteroids, chemotherapy, immunomodulators or others that modify the periodontal therapy results during the last 6 months.