Regimen for controlling or reducing dentine hypersensitivity

A method of treating a tooth surface comprising the steps:

• (a) contacting the tooth surface by contacting the tooth surface with a first composition comprising an organophosphate having the formula:
• wherein R is a hydrocarbyl comprising 4 to 22 carbon atoms;
• X and Y are each independently an alkylene comprising 2 to 4 carbon atoms;
• a and b are each independently an integer selected from 0 to 20, and a+b is in the range from 0 to 20;
• Z1and Z2 are each independently selected from hydrogen, hydrocarbyl comprising 1 to 26 carbons, and a counter ion, provided that at least one of Z1 and Z2 is hydrogen or a counter ion;
• and thereafter
• (b)occluding tubules exposed on the tooth surface by contacting the tooth surface with a second composition comprising a water-insoluble calcium phosphate, wherein the water-insoluble calcium phosphate has a calcium to phosphorus molar ratio from 1:1 to 10:1.