Biodegradable Polymer Ligatures and Auxiliaries in Orthodontics: An Empty Systematic Review.

BACKGROUND: Orthodontic ligatures and auxiliaries are essential components of fixed-appliance therapy. Conventional materials are nonbiodegradable and require periodic replacement, contributing to clinical inefficiency and environmental burden. Biodegradable polymer-based alternatives have been proposed as potential solutions. OBJECTIVE: To systematically evaluate the available evidence on biodegradable polymer ligatures and auxiliaries in orthodontics, focusing on their mechanical properties, biodegradation behavior, and clinical applicability. METHODS: A systematic search was conducted in PubMed and Scopus databases from inception to January 2026. The review followed the PRISMA 2020 guidelines. Studies evaluating biodegradable polymer ligatures or orthodontic auxiliaries were included. The screening was performed independently by two reviewers. RESULTS: A total of 149 records were identified. After removing one duplicate, 148 records were screened by title and abstract. Six studies were assessed for full-text eligibility; however, none of them met the inclusion criteria. The excluded full-text studies primarily involved conventional elastomeric ligatures, nonbiodegradable polymers, and materials lacking biodegradation properties. CONCLUSION: No studies have evaluated biodegradable polymer ligatures or auxiliaries in orthodontics. This highlights a significant research gap and underscores the need for the development and investigation of biodegradable orthodontic biomaterials.