Clear Aligner Therapy in Adults With Stage II-IV Periodontitis: A Narrative Review.

Stage II-IV periodontitis is frequently associated with pathologic tooth migration (PTM), occlusal instability, and complex restorative demands requiring coordinated interdisciplinary care. Adult patients with periodontitis increasingly request clear aligner therapy (CAT); however, its role within structured periodontal-orthodontic treatment pathways remains incompletely defined. This narrative review synthesized available clinical evidence on the use of clear aligner therapy in adults with stage II-IV periodontitis and outlined practical principles for interdisciplinary management. A literature search was conducted using PubMed, Scopus, Embase, and Google Scholar. Eligible clinical reports included adults diagnosed with periodontitis or a reduced but stable periodontium who were treated with clear aligner therapy as part of an interdisciplinary protocol and reported periodontal and/or occlusal outcomes. Nine clinical studies met the eligibility criteria, including case reports, small case series, and one prospective pilot study involving stage IV periodontitis. Across all reports, clear aligner therapy was initiated only after completion of comprehensive periodontal infection control and enrollment in regular supportive periodontal care (SPC). In stable stage II-IV patients, clear aligner therapy improved occlusal relationships and pathologic tooth migration while maintaining periodontal parameters. No study demonstrated periodontal superiority over fixed appliances. Clear aligner therapy appears to be a viable orthodontic option when integrated into a structured interdisciplinary protocol, although higher-quality prospective studies are required.