As a practical note, the normal color of teeth for most people is yellow-white – not the snow-white you see on magazine covers. No toothpaste contains enough hydrogen peroxide to affect the color of dental enamel. Plus, the toothpaste is not left on the teeth long enough. The enzyme papain, used in some toothpastes, can dissolve some stains, but not in the small amount of time toothpaste is on the teeth. There is no evidence that baking soda works in any special way. Toothpastes only work on the extrinsic stains. The safest way to whiten teeth is to have your dentist make a custom tooth tray for you. (Cost: $300 to $500.) The tray holds the whitening gel (carbamide peroxide) against only those teeth that are selected for whitening. The tray also protects the gums and back teeth from the gel, and limits the amount of get you swallow. The average person wears the tray for at least two hours a day for 10 to 14 days. Some people wear the tray while they sleep. In office whitening is more costly (between $600 and $1,000), but it can whiten teeth in only one to two visits. Whitening generally lasts for two to three years. Save your custom tooth tray – you can use it again (you just need to get more gel from your dentist). It’s impossible to know in advance how much whiter the teeth will become. People who have yellow-brown teeth get the best results; blue-gray teeth don’t respond as quickly. Bleaching will not affect your tooth-colored fillings; these will stay the same color.

The most common side effect of whitening is tooth sensitivity to heat and cold. If you apply the fluoride gel your dentist gives you for the sensitivity – before and after whitening treatments – this should not be too much of a problem. Over-the-counter or Home Shopping Network whitening kits with generic trays are not recommended. The trays do not fit the teeth well, and lengthy tooth whitening with unsafe chemicals can dissolve tooth enamel. Most users complain that these kits don’t work at all and feel they have wasted their money.

Whitening Strips contain the right ingredients for whitening and conform to the top teeth pretty well, but look closely at the disclosure for they don’t whiten in between the teeth as well as custom trays and could cause harm to exposed root surfaces. Presently, there have not been any cases of inhaling the strip, but caution is recommended.

Lamination is another way to make teeth whiter. Here, a thin portion of the tooth is removed and is replaced with a porcelain veneer. Cost: From $400 to $1,000 per tooth.