1. An oral composition for reducing dental hypersensitivity, comprising: a. an effective amount of a basic amino acid in free or salt form； and b. an effective amount of calcium silicate particles, where the calcium silicate particles have an average diameter of less than 5 μm. 2. A composition according to claim 1, wherein the particles have a d50 of 2 to 5 μm and a d90 of 5 to 10 μm, and a CVP of 3.95 at least 50%. 3. A composition according to claim 1 or 2, wherein the calcium silicate has a pH of from 8.4 to 11.2 in a 5% solution. A composition according to claim 1 or 2, wherein the calcium silicate has a surface area of from 20 to 400 m / g and a pore volume of from 0.01 to 1 cm / g. The composition of claim 1 or 2 further comprising a potassium salt. 6. The composition according to p. 5, where the potassium salt is present in a concentration of from 1 to 10% of the mass. based on the weight of the composition. 7. The composition of claim 1, wherein the oral composition provides a fluid flow rate of not more than about 45% of the fluid flow rate through etched dentin. A composition according to claim 1 or 2, wherein the basic amino acid is contained in an amount of from 0.1 to 20% based on the weight of the composition. The composition of claim 1 or 2, wherein the effective amount of calcium silicate particles is from 5 to 20% based on the weight of the composition. A composition according to claim 1 or 2, wherein the basic amino acid is arginine. A composition according to claim 1 or 2, wherein the basic amino acid is present, in whole or in part, in the form of a salt selected from the group consisting of arginine bicarbonate, arginine hydrochloride, arginine phosphate, and combinations thereof. A composition according to claim 1 or 2, wherein the basic amino acid is arginine bicarbonate. The composition according to claim 1 or 2, where the average particle diameter of calcium silicate is from 21. Композиция для ухода за полостью рта для уменьшения гиперчувст
