 3. Experimental Dentifrice For this study will be used four toothpastes: 50 Nanoencapsulated Fluoride, 100 Nanoencapsulated Fluoride, Free sodium fluoride, Without fluoride. The toothpaste, made available by the company from Brazil are packed in the same packaging and have the taste of mint. Except wash out the tubes with toothpaste will be identified by letters A, B and C by an independent researcher. The letters code will not be revealed to the participants nor the researcher who will accompany them. These will be drawn at random for daily use for seven days in four times, giving an interval of one week wash-out between them. 