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.
Unless you have severely stained teeth (ex. Tetracycline stained teeth), you should reach a very desirable shade after bleaching for 4-6 weeks. We recommend that you use your trays for 1-3 days in a row, once every 6 months, to maintain your new bright smile.Try not to consume food and drinks that stain your teeth, such as berries, cola, tea, coffee, etc.ou should use your trays with the gel at least 4-8 hours every day for the first 2-6 weeks. We recommend for you to wear your trays with the gel while sleeping at night.