Guided Alveolar Ridge Preservation (G-ARP) Using a Cortical Lamina: A Pilot Randomized Controlled Trial

Background/Obectives: Alveolar bone resorption after tooth extraction compromises esthetics and implant placement. Conventional alveolar ridge preservation (ARP) relies on grafting. This randomized controlled study evaluated a graft-free, lamina-based approach aimed at preserving ridge morphology by protecting the buccal cortical plate. Methods: Forty alveoli were randomly assigned to Guided Alveolar Ridge Preservation (G-ARP) with a subperiosteally positioned cortical lamina (test) or unassisted healing (control; CTRL). Cone-beam computed tomography (CBCT) was performed before extraction and after five months. Vertical and horizontal dimensional changes were statistically compared. Results: Healing was uneventful. At five months, the G-ARP group showed a vertical gain of 0.5 mm and a horizontal reduction of 0.2 mm, whereas the CTRL group exhibited a vertical loss of 1.7 mm (p < 0.01) and a horizontal loss of 2.7 mm (p < 0.001). Effect sizes were large for vertical change and very large for horizontal change (Hedges' g = 0.95 and 2.19, respectively). Regeneration occurred through native bone formation without grafts. Conclusions: Subperiosteal placement of a cortical lamina effectively preserved ridge dimensions after extraction. This graft-free approach may offer technical and biological advantages while supporting new bone regeneration.