Development of an Innovative Strontium Gel for Enhanced Antisensitivity, Long-Lasting Film Formation, and Sustained Release of Active Ingredients on Oral Tissues

This study introduces a novel strontium acetate–sodium hyaluronate–sodium alginate hydrogel (Sr-hydrogel) designed to address dental hypersensitivity (DH) through enhanced antisensitivity, robust film formation, and sustained bioactive retention on dental tissues. By integrating high-molecular-weight hyaluronic acid (HMW HA, ∼1450 kDa) with alginate, the hydrogel employs strontium ions (Sr2+) as both a cross-linker and a remineralizing agent. Sr2+-mediated ionic cross-linking forms a cohesive, shear-thinning network with strong adhesion to hydroxyapatite, resisting salivary washout while enabling precise application. Optimization highlighted the critical roles of strontium, alginate, and HMW HA in ensuring viscoelasticity and mechanical stability of Sr-hydrogel. The Sr-hydrogel exhibited sustained Sr2+ release/retention over hours. In vitro tests demonstrated 88% tubule occlusion, significantly outperforming controls due to prolonged Sr2+ retention. Coupled with excellent biocompatibility, the Sr-hydrogel offers a promising platform for DH treatment and regenerative dental applications, meriting further clinical evaluation for long-term efficacy and pain relief.