1 concentration gradient The difference in the concentration of a chemical across a membrane. 2  cytoplasm The living substance inside a cell (not including the nucleus). 3  diffusion The movement of particles (molecules or ions) from an area of higher concentration to an area of lower concentration.
Not all stains can be lightened by over-the-counter or professional bleaching, and your dentist will be able to give you guidance. If you have sensitive teeth, gum disease or teeth with worn enamel, your dentist may discourage tooth whitening.
The tooth shade guide makes it easy to see and measure the result of your whitening. A professional tooth shade guide is included with all the Dentaworks teeth whitening systems and can also be purchased separately. Make sure you get a tooth shade guide when you purchase your whitening kit.