Many of us encounter a dizzying array of toothpastes in the oral care aisle, from anti-cavity to whitening to tartar control. Some products promise all of the above and more. So how does a tartar control toothpaste help prevent the unsightly build-up we know as tartar? By fighting fire with fire, that's how.

First, a little bad news for those looking for an improved smile. Tartar control toothpaste cannot remove previous tartar build-up. Only a trained dentist can scrape away the hardened calcium above and below the gumline. Yes, it's just as pleasant as it sounds. What tartar control toothpaste does is halt the progress of the destructive chemicals responsible for the creation of tartar.

The tartar cycle begins with food. When food particles are allowed to remain on the teeth after eating, bacteria begins to feed on them. These living organisms excrete acids that leech out calcium from tooth enamel, a process called demineralization. Eventually, this demineralization process creates cavities and fissures in the tooth, and puts the 'decay' in tooth decay. This compound of calcium and acid combines with oxygen to form a substance called calcium phosphate.

Calcium phosphate tends to bond with existing enamel along the gumline and work its way up the tooth. This is the hard, yellowish material which must be scraped away with metal tools. Calcium phosphate will continue to form as long as the cycle of acid production and demineralization remains unchecked. Brushing with regular toothpaste removes the acid deposits and food particles, but the tartar will remain.

This is where tartar control toothpaste enters the picture. Chemists working for the oral care industry discovered that calcium phosphate is an insoluble form of phosphate. This means that existing tartar build-up cannot be dissolved in water. The solution to this problem was to create a form of phosphate that is soluble which combines chemically with the destructive calcium phosphate. This active ingredient in tartar control toothpaste is called sodium pyrophosphate.

When a tartar control toothpaste containing the soluble sodium pyrophosphate is applied to the teeth and gums, a chemical bonding process occurs. Any calcium phosphate which has not yet bonded to teeth is attracted to the sodium pyrophosphate. When the new compound mixes with water, it is completely dissolved. This means that the destructive calcium phosphate destined to form more tartar is instead removed with the rinse water. Tartar control toothpaste cannot dissolve tartar which has already bonded with the enamel, but it can stop future deposits from forming.

Some users of tartar control toothpaste may experience more tooth sensitivity, since the enamel layer becomes a little thinner over time. Others may develop canker sores due to the higher sodium content of the toothpaste. Tartar control toothpastes may also contain bleaching agents for tooth whitening.

When in doubt, look at the ingredient list on the box. Tartar control toothpastes should include sodium pyrophospate as an active ingredient. This is not the same as sodium laureth sulfate, which is a compound used as a detergent. Those who are prone to canker sore formation might want to avoid toothpastes with high levels of sodium-based compounds.