In this study it will be investigated the usefulness of Platelet-Rich Fibrin (PRF) on in the epithelialized connective tissue graft palatal donor site healing acceleration and in the patient's morbidity reduction. Forty patients, with at least one gingival recession will be treated by a coronally advanced flap (CAF) with connective tissue graft(CTG) resulting from the de-epithelialization of a free gingival graft. In the test group (20 patients) a quadruple layer of PRF membrane will be placed over the palatal wounds; conversely, the control group patients will be treated by an absorbable gelatin sponge. Patients will be monitored at 1, 2, 3 and 4 weeks after surgery for the complete re-epithelialization of the palatal wound (CWE), the alteration of sensibility (AS) around the wound area, the post-operative discomfort (D), and the changes of feeding habits (CFH) by a visual analogic scale (VAS) evaluation. Furthermore, the analgesics consumption and the existence of delayed bleeding from the palatal wound (DWB) during the first post-operative week will be assessed.

Inclusion Criteria: are as follows:

• to have a single gingival recession to be treated by a mucogingival surgery intervention
• to be in good systemic health
• to have a good oral hygiene

Exclusion Criteria:

• no systemic diseases; no coagulation disorders; no medications affecting periodontal status in the previous 6 months; no pregnancy or lactation;
• no smoking habits;
• no periodontal surgery on the experimental sites;
• no inadequate endodontic treatment
• no tooth mobility at the site of surgery