A full-thickness coronally-advanced tunnel (Modified Coronally Advanced Tunnel - MCAT) will be performed according to Aroca et al. (2010).

Defined as the reduction in recession in the mid-buccal aspect with respect to baseline. It will be calculated at 3- and 6-months after surgery and evaluated as linear mid-buccal measurement (mm, with probe).

Defined as the change in the linear distance between the contact point and the top of papilla at the mesial aspect of each tooth (Aroca et al. 2010) with respect to baseline. It will be measured at 3- and 6-months after surgery and evaluated as linear measurement (mm, with probe).

Defined as the linear changes in mid-buccal keratinized tissue height (distance from the gingival margin and the mucogingival junction) with respect to baseline. It will be calculated at 3- and 6-months after surgery and evaluated as linear mid-buccal measurement (mm, with probe).

Defined as the changes in PPD (distance from the gingival margin to the bottom of the probeable sulcus) with respect to baseline. It will be calculated at 3- and 6-months after surgery and evaluated only as linear mid-buccal measurement (mm, with probe).

Defined as the changes in CAL (distance from the CEJ to the bottom of the probeable sulcus) with respect to baseline. It will be calculated at 3- and 6-months after surgery and evaluated only as linear mid-buccal measurement (mm, with probe).

Assessed by 10 s air spray applied to the buccal cervical area. It will be evaluated at baseline and at 3- and 6-months after surgery.

Evaluated at 3- and 6-months according to Cairo et al. (2009).

Defined as the percentage of root surface coverage obtained with respect to baseline. The sMRC will be measured at 3- and 6-months after surgery. It will be assessed as buccal surface measurement (% mm2, digital assessment).

Defined as the presence/absence of complete root surface coverage. It will be measured at 3- and 6-months after surgery and evaluated as buccal surface measurement (mm2, digital assessment).

Defined as the reduction in recession surface with respect to baseline. It will be calculated at 3- and 6-months after surgery and evaluated as buccal surface measurement (mm2, digital assessment).

Defined as the changes in the area between the contact point and the top of papilla at the mesial aspect of each tooth with respect to baseline. It will be measured at 3- and 6-months after surgery and evaluated as area measurement (mm2, digital assessment).

It will be measured both at the gingival margin and 1-mm apically. It will be assessed as a mid-buccal thickness measurement (mm, digital assessment) at 3- and 6-months after surgery.

Defined as the changes in keratinized tissue surface (surface delimited apico-coronally by the gingival margin and the mucogingival junction and mesio-distally by the projection of a line passing by the contact-point and perpendicular to the occlusal aspect of each tooth) with respect to baseline. It will be calculated at 3- and 6-months after surgery and evaluated as buccal surface measurement (mm2, digital assessment).

It will be defined as the time (days) to reach a pain VAS<10.

The patient will document in the evening, preferably at the same time, the number of ibuprofen tablets taken each day from day-0 to day-7 and at day-14 post-surgery.

The patient will self-report on a 100-mm VAS scale ranging from 0 (no swelling whatsoever) to 100 (worst swelling imaginable) the perceived swelling. The swelling will be reported just after surgery, 12 hours post-operatively and 1, 2, 3, 4, 5, 6, 7, 14 days post-operatively in the evening, preferably at the same time.

The patient will self-report on a 100-mm VAS scale ranging from 0 (no bleeding whatsoever) to 100 (continuous copious bleeding) the perceived bleeding. The bleeding will be reported just after surgery, 12 hours post-operatively and 1, 2, 3, 4, 5, 6, 7, 14 days post-operatively in the evening, preferably at the same time.

The patient will answer on a 100-mm VAS scale just after the surgery to the following question: "How did you perceive the procedure?" (Burkhardt et al. 2015). The VAS scale will range from 0 (no problem whatsoever) to 100 (unbearable).

The patient will self-report on a 100-mm VAS scale ranging from 0 (terrible) to 100 (perfect) the perceived aesthetic of the included zone. The aesthetic self-evaluation will be completed 6 months post-surgery.

The patient will self-report on a 100-mm VAS scale ranging from 0 (terrible) to 100 (perfect) the overall satisfaction for the treatment of the included zone. The satisfaction self-evaluation will be completed at 6-months post-surgery.

The OHIP-14 questionnaire will be evaluated at 1, 2, 3, 4, 5, 6, 7, 14 days and 6 months post-surgery.

Patient concerns with gingival recession will be assessed with a condition-specific health-related quality-of-life instrument (Tonetti et al. 2018) assessing the level of concern in terms of aesthetics, sensitivity to cold, sensitivity to brushing, root/tooth wear, development of cavity and fear to lose the involved teeth using a questionnaire on a 5-point Likert scale at 6 months.

The time in minutes of the net (excluding time used for photographs or other non-surgery related things) duration of the surgery in the recipient site (after palate suture), from the first incision to the completion of the last suture (the composite stops placement in the control group will be considered within the duration of surgery).

It will be evaluated by the outcome assessor on a 100-mm VAS scale ranging from 0 (very bad) to 100 (very good). The early wound healing will be evaluated at 1 and 2 weeks post-surgery.

It will be evaluated on patients treated in one of the centers, using a 3D printed stent, just after surgery, and at 1-, 2- and 4-week, as well as 3- and 6-months examinations, after-surgery.