Partial-thickness/Non-advanced vs. Full-thickness/MCAT Tunnelling for the Treatment of Multiple Gingival Recessions

Included patients will be randomly allocated to the test (split-thickness non-advanced tunnel - Zabalegui et al. 1999) or to the control group (full-thickness coronally-advanced tunnel - MCAT - Aroca et al. 2010).

Design: Randomized, clinical, outcome-assessor blinded, multi-centric, superiority trial with two parallel groups and a 1:1 allocation ratio. The follow-up of individual patients will be 6 months (to be extended to 3/5 years if funding will be available)

Patients with a minimum of two-adjacent teeth with RT1 and/or RT2 gingival recessions (at least one with a depth \>2 mm) with indication for root coverage treatment will be included. RT2 gingival recessions will be considered not eligible when associated with interproximal exposure of the CEJ.

Mean root coverage (linear) at 6-months will be evaluated as the primary outcome by a blinded outcome assessor.

Eligibility Criteria:
Any patient having a minimum of two adjacent teeth with RT1 and/or RT2 gingival recessions (at least one with a depth \>2 mm) with indication for root coverage treatment, being at least 18 years old and able and agreeing to sign a written informed consent form will be potentially eligible for this trial. RT2 gingival recessions will be considered not eligible when associated with interproximal exposure of the CEJ (interdental gingival recession).

In case of multiple RT1/RT2 recessions involving 2 or 3 teeth, at least 2 or 1 more non-included adjacent teeth should respectively be present in order to guarantee a minimum of 4 adjacent teeth (including the included ones) in the region of interest (ROI) for digital scanning.

Patients fitting to all the inclusion criteria as above will be not included in the study if they appear to be unable to attend to the study-related procedures (including the follow-up visits) or if one or more of the following systemic or local exclusion criteria are found in the enrollment phase.

Systemic primary exclusion criteria:

* Compromised general health which contraindicates the study procedures (ASA IV-VI patients);
* Systemic diseases/medications which could influence the outcome of the therapy (e.g., uncontrolled diabetes mellitus);
* Current smokers (self-reported, any type of smoking), users of chewing tobacco, and drug/alcohol abusers;
* Pregnant or nursing women;

Local primary exclusion criteria:

* History of previous periodontal surgery (mucogingival or other) on the teeth to be included;
* Patients having had surgical soft tissue augmentation procedures in the ROI within the previous 12 months;
* Furcation involvement in the teeth to be included;
* Presence of severe tooth malposition, rotation or clinically significant super-eruption in the teeth to be treated;
* Presence of fixed or removable prosthesis in the area to be treated;
* Presence of RT3 gingival recessions in the same surgical area of the treatment.

Secondary exclusion criteria (after initial therapy is provided):

* Not able to achieve good oral hygiene and control gingivitis in the whole of the dentition (FMPS \< 20% and FMBS \< 20%);
* Persistence of uncorrected gingival trauma from toothbrushing.