Nano-hydroxyapatite is one of the most biocompatible and bioactive materials on account of its similarity to the mineral compositions found in teeth. In our study, the occluding abilities of different concentration nano-hydroxyapatite solution and their resistance to brushing power were tested. 45% were elected as a proper concentration after specimens were treated by nano-hydroxyapatite solution. Then specimens were immersed into two toothpastes (Sensodyne and Toothmousse) containing different components (fluoride and caesin phosphopeptide - amorphous calcium phosphate respectively), and the effect of these components on the nano-hydroxyapatite layer were researched. The nano-hydroxyapatite layer treated by with Sensodyne toothpaste got thinner and possibly had stronger ability to withstand acid attack than that of Toothmousse toothpaste.