Research Progress of Hydrogels in the Treatment of Periodontitis

Periodontitis is a chronic infectious disease driven by dental plaque biofilms. Its core pathological features are local microbiome dysbiosis, immune homeostasis disruption, and progressive destruction of periodontal support tissue. Traditional mechanical debridement combined with conventional medications struggles to overcome key clinical limitations, such as poor drug retention in deep periodontal pockets, ineffective eradication of refractory biofilms, and insufficient alveolar bone regeneration. In recent years, hydrogels have become an ideal platform for periodontal local minimally invasive drug delivery and tissue engineering due to their highly hydrated three-dimensional networks, excellent biocompatibility, and adjustable physical and chemical properties. This review systematically presents the latest research progress of functionalized hydrogels in the treatment of periodontitis. Firstly, the material basis underlying their adaptation to the complex periodontal pocket microenvironment is discussed from three aspects: wet adhesion, in-situ injectability, and controlled degradability. Secondly, the smart response drug release mechanism based on pathological microenvironment markers such as local acidity (pH), high levels of reactive oxygen species (ROS), specific enzymes, and glucose is elaborated. On this basis, the review deeply analyzes the multi-dimensional mechanism by which hydrogels promote the remodeling of the periodontal immune-inflammatory microenvironment and alveolar bone regeneration through the delivery of various bioactive agents such as antibiotics, antioxidants, osteogenic inducers, etc. Finally, the key challenges faced by hydrogels in clinical transformation are discussed, including mechanical adaptability, predictability of in vivo degradation timing, and coordinated multi-tissue regeneration, and future research directions are proposed to support precision-targeted, functional regenerative therapies for periodontitis.