Bridging the Hydration Barrier: Hydrogel Adhesives for Oral Hard–Soft Tissue Integration

Oral hard-soft tissue repair present significant clinical challenges due to the highly dynamic, moist, microbially colonized, and inflammatory nature of the oral environment. Oral wounds from trauma, surgery, or disease cause discomfort and infection risk, demanding effective protection. The development of wet adhesives capable of robust adhesion to integrate oral hard tissues and soft tissues, while enabling localized therapy, remains a significant challenge. In recent years, hydrogels with tunable surface energy and reversible adhesion have demonstrated exceptional wet adhesion through the synergy of physical, chemical, and dissipative interactions, showing great potential to improve therapeutic effect in oral surgical applications. This review comprehensively examines wet adhesion mechanisms of hydrogels and critically analyzes the physical and chemical foundations of current dental adhesives. By integrating surface modification of hydrogels to the unique requirements of oral soft and hard tissue repair, this work aims to develop next-generation materials that overcome clinical translation barriers.