Polymeric Biomaterials with Multiple Stratified Layers for Periodontal Ligament/Bone Regeneration: A Review

Periodontitis is a chronic pathological condition initiated by bacterial plaque accumulation and characterized by the progressive destruction of the tooth-supporting tissues, including the periodontal ligament, cementum, and alveolar bone. If left untreated, it may result in tooth mobility, pathologic tooth migration, and ultimately tooth loss. Despite numerous regenerative strategies, complete periodontal regeneration remains challenging. Guided tissue regeneration (GTR) and guided bone regeneration (GBR) promote the regeneration of the periodontal ligament and alveolar bone; however, current GTR/GBR biomaterials often exhibit inadequate mechanical stability and osseointegration. To overcome these limitations, various multilayer biomaterials with enhanced functionalities have been developed. This review outlines the key properties required for GTR/GBR, evaluates the design and performance of current multilayer biomaterials, and examines their major limitations, particularly their inability to fully replicate native periodontal tissues due to structural incompatibilities between layers. Finally, future directions and recommendations are presented to guide the development of next-generation GTR/GBR biomaterials.