Stabilization of Zinc Ions and Potassium Phosphates Using Milk Protein Hydrolysates and In-Vitro Evaluation of Dentinal Tubule Occlusion

Objective: In this study, we propose a method to stabilize ZnCl2 and potassium phosphates using milk protein hydrolysates (MPHs) to develop a dentifrice that alleviates dentin hypersensitivity. Methods:The changes in particle size of dispersions containing ZnCl2, KH2PO4, K2HPO4, and MPHs in aqueous solutions were monitored, and the interactions between each component were identified.A dentifrice containing a stabilized complex of ZnCl2, potassium phosphates and MPHs was prepared, and its efficacy to inhibit dentin permeability was quantitatively demonstrated.Results: ZnCl2, KH2PO4, K2HPO4, and MPHs spontaneously formed nanocomplexes in aqueous solutions.These complexes rapidly aggregated upon contact with hydroxyapatite.The aggregation resulted in effective dentinal tubule occlusion and provided high acid resistance. Conclusion:The dentifrice containing a complex of ZnCl2, potassium phosphates and MPHs has been shown to have the efficacy of occluding dentinal tubules and may help relieve dentin hypersensitivity.