Acute Oroantral Communication Closure: Resorbable Collagen Membrane vs. Buccal Advancement Flap Outcomes: A Clinical Trial

Background: Oroantral communication (OAC) is a frequent complication after the extraction of maxillary posterior teeth and requires immediate closure to prevent sinus pathology and long-term functional impairment. Objectives: This study aimed to compare the clinical and radiographic outcomes of acute OAC closure using resorbable heterogeneous collagen membranes with those of the conventional buccal advancement flap (Rehrmann method). Methods: Twenty-four patients with OACs diagnosed within 24 h post-extraction were enrolled, and 20 completed follow-up. Patients were allocated to a membrane group treated with a resorbable collagen membrane (Creos Xenoprotect) or a control group treated with a buccal advancement flap. Clinical parameters, including vestibular depth, width of keratinized gingiva, alveolar socket dimensions, postoperative complications, and pain intensity assessed using the Visual Analogue Scale, were evaluated at 1, 7, 14, and 90 days. Radiographic outcomes were assessed using cone-beam computed tomography with linear measurements and normalized bone density analysis in Hounsfield Units at baseline and 90 days. Results: The membrane technique provided significantly better preservation of vestibular depth, keratinized gingiva width, and alveolar socket dimensions, with significantly lower postoperative pain and fewer complications compared with the buccal advancement flap. Higher normalized bone density values were observed in the membrane group, although differences were not statistically significant. Conclusions: Resorbable collagen membranes represent a safe, minimally invasive, and clinically effective alternative to buccal advancement flaps for acute OAC closure.