Commercial whitening toothpastes vary greatly in their ability to whiten teeth. They work by removing surface stains from the teeth with the use of mild abrasives. Toothpastes that are effective in removing stains can also destroy tooth enamel in the process. These toothpastes use harsh abrasives. With repeated use, harsh abrasives begin to damage tooth enamel and can contribute to increased tooth sensitivity. If you would like to try a whitening toothpaste, consult with your dentist first.