Autogenous vs. Xenogeneic Peri-implant Soft Tissue Grafts Placed in Full vs. Split Thickness Flaps

Inclusion Criteria: Any male or female adult (≥ 18 year old) patient from the University Complutense of Madrid, being able to sign an informed consent form, presenting a submerged dental implant scheduled to undergo a second stage surgery, which is bounded mesially or distally by a remaining natural tooth, and exhibits a lack of buccal soft tissue volume, will be potentially eligible for this trial. The case definition for a lack of buccal soft tissue volume will be the presence of a thin buccal mucosa (\< 2mm) or a minor volumetric contraction of the alveolar process (flat or concave buccal mucosal profile at the edentulous area). Exclusion Criteria: Patients fitting to all the above inclusion criteria will be not included in the study if 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 will be found during enrolment or through the study: Systemic primary exclusion criteria: * Compromised general health status contraindicating the study procedures (≥ASA IV); * Drug abuse, alcohol abuse, or smoking \> 10 cigarettes a day; * Chronic use of corticosteroids, NSAIDs, or immune-modulators (any type, any dose); * Assumption of bisphosphonates (any type, any dose, past or present); * Pregnant or nursing women; * Hypersensitivity to paracetamol; Local primary exclusion criteria * History of previous mucogingival surgeries in the area of interest; * Lack of adequate vestibu…