The invention encompasses combinations of bioactive glass composition and potassium salts that are useful in conjunction with delivery agent such as, for example, toothpastes, mouthwashes, and oral gels. In certain embodiments, the compositions of the invention form a rapid and continuous reaction with body fluids (e.g., saliva) to promote the immediate and long-tem release of Ca and P ions to produce a stable crystalline layer deposited onto and into the dentin tubules for the immediate and long term reduction of dentin hypersensitivity and tooth surface remineralization.