Rapid and durable dentinal tubule occlusion via ion-mediated intratubular coprecipitation

Objectives Dentin hypersensitivity arises from fluid movement within patent dentinal tubules. Existing chemically mediated occlusion strategies require days to weeks, limiting clinical applicability. This study developed a rapid CaCl₂/AgF regimen for durable dentinal tubule occlusion. Methods Human third molars were acid-etched with 37% phosphoric acid for 15 s to establish an exposed dentin model. Specimens were sequentially treated with 0.05 M CaCl₂ and 0.1 M AgF for 20 s each (Ca-Ag group). Gluma, Duraphat, and Actimins served as comparators. Tubule occlusion, surface hardness, resistance to abrasive, ultrasonic, and acidic challenges, and fluid transport through pulp were evaluated. Results The Ca-Ag regimen achieved near-complete tubule occlusion (97.5 ± 1.4%) with deep intratubular deposits (96.0 ± 10.5 μm), significantly outperforming commercial desensitizers (p < 0.001). Tubule sealing remained stable after abrasive (92.2 ± 4.3%), ultrasonic (93.8 ± 2.8%), and acidic (95.2 ± 1.9%) challenges. Surface hardness increased from 34.5 ± 2.8 HV to 46.3 ± 3.7 HV. Under 15 cm H₂O pulp pressure, Ca-Ag markedly reduced fluid penetration, decreasing the mean fluorescence intensity from 173.9 ± 14.8-37.4 ± 6.5 AU (p < 0.001), whereas minimal reductions were observed in the other groups. Conclusions CaCl₂/AgF treatment enables rapid, deep, and durable dentinal tubule occlusion with strong resistance to mechanical and chemical challenges. Significance The Ca-Ag regimen provides a rapid and durable ex vivo dentinal tubule occluding strategy. The clinical desensitizing efficacy and long-term performance require validation through well-controlled in situ and clinical trials.