Your smile and the appearance of your teeth should be at the top of your beauty routine list. Drugstore whiteners will make a small difference in the color of your teeth, but if you want immediate, drastic results, try Opalescence. I don't think you can purchase this whitener over the counter. You must visit your dentist to have custom trays made to fit your teeth perfectly and purchase Opalescence from your dental office. 

The trays are soft rubber and easy to wear. Your dentist will tell you to try thirty minutes wearing the solution, but if you have sensitivity, decrease the time you wear the whitener. You only need a small amount of the gel on each tooth. If you applied to much of the whitener and it seeps onto your gums, they will burn and turn white. Don't worry, this is temporary. Your gums will return to their natural color within a few hours. I suggest using Sensodyne while whitening your teeth; it helps with the sensitivity.

You will see immediate results with Opalescence whitening. Your teeth will become brighter with each application.