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

CaCl₂/AgF treatment achieves rapid ex vivo dentinal tubule occlusion within 40 s. • Co-precipitation generates deep intratubular deposits (∼96 μm). • Occlusion remains stable after brushing, ultrasonication, and acidic challenges. • CaCl₂/AgF treatment reduces fluid transport under simulated pulpal pressure. • The Ca–Ag strategy shows promise for durable dentinal tubule occlusion. 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 H 2 O 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.