Guided Bone Regeneration Using Fixed vs Non-Fixed Resorbable Collagen Membranes

Inclusion Criteria: 1. Men and women over 18 years old or older 2. Patients requiring Guided Bone Regeneration due to insufficient ridge width(≤5mm) to place dental implants, with sufficient vertical ridge height (≥9mm) from vital anatomical structures (the inferior alveolar nerve in the Mandible, or the sinus in the Maxilla) 3. One or more teeth missing in posterior zone (Premolars, and Molars) 4. Absence of active Periodontal disease 5. Good level of oral hygiene (Plaque index \<25%) 6. Absence of systemic diseases that could influence the outcome of the therapy (Uncontrolled diabetes, osteoporosis, bisphosphonate medications) 7. Non smokers or light smokers (\<10 cigarettes per day) 8. Informed consent signed Exclusion Criteria: 1. Patients with sufficient ridge width (\>5 mm) and height (≥9mm) from vital anatomical structure) requiring no GBR to place dental implants 2. Patients with severe horizontal and vertical defects requiring other surgical techniques. 3. Long-term non-steroidal anti-inflammatory drug therapy (3months). 4. Lactating females or currently pregnant women. 5. Severe cognitive or psychiatric disorders. 6. Unwillingness to return for follow-up examination.