In-depth occlusion of dentine tubules via the application of (poly-L-aspartic acid)‑strontium and phosphate/fluoride to treat dentine hypersensitivity

Dentine hypersensitivity (DH) is a common oral health issue and occlusion of the exposed dentinal tubules (DTs) is regarded as the most effective therapeutic treatment nowadays. However, it is still difficult to develop easy and effective strategies for deep occlusion of DTs. In this study, we develop a strategy for occluding DTs deeply and compactly via simple application of occlusion media including (poly-L-aspartic acid)‑strontium (PAsp‑strontium) and phosphate/fluoride. The bonding of strontium ions to poly-L-aspartic acid formed a positively charged PAsp‑strontium complexes. After application of 15 min each, the PAsp‑strontium and phosphate/fluoride rapidly penetrated into the DTs in turn via the electrostatic interaction, then occluded the DTs with crystals up to a depth of 150 μm. The occlusion within DTs was resistant to abrasive and acidic challenges. The occlusion media performed better than commercial desensitizers Duraphat and Gluma. Moreover, this strategy possessed sufficient biocompatible and excellent performance in vivo. The application of occlusion media would shed light on in the management of DH.