How can I whiten old yellow teeth?

[dharani0022]

Home tooth-whitening kits available in the market contain bleach called carbamide peroxide, which helps to remove both surface and deep stains of tooth. It actually has the ability to change the natural tooth color. The peroxide based gel in some kits needs to be applied on the surface of the teeth using a small brush. In other kits, this gel is filled in a tray which molds to the teeth. One would need to wear this tray for about 30 to 45 minutes daily for a week or more to get rid of the dental stains. This method proves extremely effective in eliminating coffee stains from the teeth.

http://www.youtube.com/watch?v=g9NZMmxkhgw