Stability of the Marginal Bone Around Subcrestal Implants

Inclusion Criteria: * indications for the insertion of two implants in a free edentulous ridge in the posterior area of both arches (premolar / molar area), based on a careful diagnosis and treatment plan; * presence of a residual bone crest with a minimum surgical height of 9 mm, and a thickness of at least 6 mm at the level of the planned implant sites; * the bone crest must be healed (at least 6 months after tooth loss / extraction of the corresponding dental element); * native bone; * plaque index below 25% and bleeding index below 20%; * facial-lingual width of the adherent gingiva ≥ 4 mm; * age of the patient\> 18 years; * patients must be able to review and understand the study protocol; * informed consent. Exclusion Criteria: * acute myocardial infarction within the last 6 months; * uncompensated coagulation disorders; * uncontrolled diabetes (HbA1c\> 7.5%); * head / neck radiotherapy in the last 24 months; * immunocompromised patients (HIV infection or chemotherapy within the last 5 years); * present or past treatment with antiresorptive drugs; * psychological or psychiatric problems; * alcohol or drug abuse; * presence of uncontrolled periodontal disease * acute and chronic endodontic infections next to implant site.