Effects of collagen membrane on bone level and periodontal status of adjacent tooth after third molar surgery: a randomized controlled trial

BACKGROUND: The periodontal status and distal bone level of the adjacent second molar can be negatively affected by the surgical extraction of an impacted lower third molar. Absorbable materials have some benefits, including enhancing primary wound coverage and promoting wound healing through isolation, clotting, wound stabilization and haemostasis. This study set out to compare primary and secondary healing and collagen-membrane-based primary healing after surgical removal of partially erupted impacted third molars (3Ms), evaluating the distal alveolar bone level (ABL) and periodontal status of the adjacent second molars (2Ms). METHODS: Patients who met the inclusion criteria were randomized into three groups: secondary healing (n = 28), primary healing (n = 27) and membrane-based primary healing (n = 29). Digital panoramic radiographs were obtained preoperatively (T1) and three months postoperatively (T2). The distances between the cemento-enamel junctions and the alveolar bone crests on the distal aspects of the adjacent 2Ms were measured using calibrated radiograph measurement software. The pocket depth and plaque index measurements were performed preoperatively and three months postoperatively. The periodontal plaque index (PPI) scores were registered on the distal aspects of the 2Ms, and the mean values were used. RESULTS: Three of the applied healing types positively affected periodontal pocket depth (PPD) and periodontal index values (p < 0.05). In terms of the ABL of the adjacent 2Ms, primary healing (p < 0.05) and membrane-based primary healing (p < 0.05) had superior results to secondary healing. CONCLUSION: Membrane use is promising for the distal bone gain and periodontal status of the adjacent 2M. TRIAL REGISTRATION: This clinical study was registered by the Australian New Zealand Clinical Trials Registry, with the trial number ACTRN12618001551280.