Does surgical removal of mandibular third molar influence the periodontal status of the adjacent second molars? A systematic review

Objective: This study aimed to assess the influence of mandibular third molar surgical removal on the periodontal status of adjacent second molars and to investigate the potential impact of the flap design. Methods: A systematic review of the literature, registered in PROSPERO, has been carried out from Pubmed and Scopus databases following PRISMA guidelines from January 2010 to January 2022. PICO method was used to select the relevant articles. Studies comparing the periodontal status of the second molar before and after mandibular third molar removal were considered. Results: Twenty-three studies involving 1067 patients were included. The two main parameters studied were periodontal pocket depth and clinical attachment level. The envelope flap and the triangular flap were the most commonly used flap techniques. Periodontal health of adjacent second molar was maintained or improved in most of the included studies. The flap design did not seem to have a significant influence either. Conclusion: Avulsion of impacted third molar in healthy young adults does not impair the periodontal health of adjacent second molars. Further studies, with higher levels of evidence, are needed to confirm these results and to identify possible risk factors (such as age, impaction depth or periodontal disease) responsible for poorer healing.