Wisdom across interfaces: Adhesion mechanism and application potential of wet-adhesive hydrogel in periodontal tissue

Periodontitis, a chronic inflammatory disease of periodontal tissues closely linked to systemic health, presents significant therapeutic challenges due to the dynamic and moist microenvironment of these tissues. Current local therapeutic systems lack adaptability to this unique microenvironment, making it difficult to guarantee treatment efficacy at the target site. Wet-adhesive hydrogels, with their exceptional tissue adhesion and multifunctionality, demonstrate tremendous potential as emerging materials for periodontitis treatment. In this review, we systematically summarize recent advances in wet-adhesive hydrogels for periodontitis research, covering their adhesion challenges, mechanisms, material types, diverse biological applications and clinical translation. We begin with analyzing the unique anatomical structure and physiopathological microenvironment of periodontal tissues, revealing the fundamental causes that hinder long-term retention of local therapeutic systems. We then explore the chemical and physical adhesion mechanisms of wet-adhesive hydrogels, elucidating the scientific basis that supports their adaptation to the distinctive periodontal environment. Furthermore, we systematically categorize various adhesive hydrogel types along with their adjustable physicochemical properties, establishing a crucial link between adhesion mechanisms and clinical translation. We then summarized the multidimensional applications of wet-adhesive hydrogels in periodontitis, including wound protection and isolation, barrier membranes, stimuli-triggered drug delivery, hemostasis, electrical stimulation, stress conduction, and monitoring. Finally, we comprehensively discuss the current status and challenges of clinical translation. Our aim is to provide both theoretical foundation and practical guidance for developing next-generation intelligent and personalized periodontal treatment platforms.