With at home teeth whitening kits a mouthpiece is filled with a bleaching agent and worn overnight. The mouthpieces can either be fitted to your teeth or come in a standard size. Both methods work effectively, however fitted mouthpieces produce better results overall, but cost more.

Some at home teeth whitening systems work better than others. When selecting an at home teeth whitening system pay attention to the concentration of Carbamide Peroxide. The most effective at home teeth whitening systems use a mixture between 10 and 22%. For optimum comfort and effectiveness, try to find a formula at either 15% or 16%.

It's important to remember, some tooth discolorations will be more resistant to at home bleaching than others. At home teeth bleaching processes will not make a color change in dental work you have already done. This includes restorations such as: white fillings, bonding, crowns, and bridges. In most cases, a person's teeth should be whitened first and then afterwards their dental work replaced so to match the new shade of their teeth.

Advantages: Most home whitening kits are effective and have the potential to whiten your teeth up to 10 shades depending on what brand you buy. These kits also cost less. Usually between $100 - $200 for a good whitening kit.

Disadvantages: Most people find wearing the mouthpieces overnight bothersome. There are alternatives. Some at home whitening kits require you to wear the mouthpieces for shorter periods of time (usually 30 minutes or less).