Although hydrogen peroxide is usually the bleaching agent used in in-office procedures it could also be used at home for those who do not have hypersensitivity in the gums or in the teeth. For most practices though Carbamide peroxide is used for home whitening kits. Carbamide peroxide although slower acting also works very much like a hydrogen peroxide. Teeth Whitening and Bleaching Unlike temporary teeth which are shiny, very white and very clean looking, the permanent teeth that follow once the deciduous teeth are lost are usually less porous. Because of this, permanent teeth come in varying shades from white to off-white and sometimes to yellowish. The dirt and the stains at the surface of the teeth will be removed, and will be primed up for the whitening session courtesy of the whitening toothpaste. Buy the desensitizing toothpaste. This is one good investment if you want to take teeth whitening seriously. This can be used before and after using the teeth whitening toothpaste. The youthful glow and sparkle of young teeth will in time lost its sheen as the enamel starts developing tiny cracks that will eventually lose the crystalline rods in the tooth, thinning the enamel making the teeth more transparent and showing through the yellowish color of the dentin. Even discounting this natural aging of the teeth, eating habits, food choices, medication, lifestyles, health conditions and many other factors will develop the tiny cracks in the enamel allowing debris to accumulate between the spaces staining the teeth. And to get into the safer track, when shopping for this kind of toothpaste you may want to get the paste that carries the seal of approval of the American Dental Association. The seal of approval indicates that the toothpaste that you are holding has been found to be effective in cleaning and in making the teeth white. No matter, it will always be safest to consult with a dentist before any teeth whitening are applied. This may cause a little inconvenience for a time but then it is always best and for the most part it is only a one time visit. After that you could be on your own and consider home kits and self help solutions.