Can toothpastes really whiten teeth?
Hippocrates used a powder made from the skeletons of mice. Pliny the Elder used burnt eggshells, and the ancient Arabs resorted to twigs from the Arak shrub. What were they trying to do? Clean their teeth! Long before humans understood the chemical process of tooth decay and its health consequences, they struggled to have white teeth. This isn’t surprising given the allure of a bright white smile and the repulsion caused by a mouthful of decaying teeth. Today the battle for healthy pearly whites has taken on a novel dimension with toothpaste manufacturers making a bevy of scientific claims on behalf of their products, with the term “whitening” being prominently featured. The fact is that no toothpaste can whiten teeth. That can only be effectively done by a dentist using the bleaching activity of hydrogen peroxide. Since people are familiar with peroxide’s bleaching ability, manufacturers add it to toothpaste hoping to cash in on its whitening appeal. Study upon study, however, shows that peroxide toothpastes are no more effective teeth whiteners than other toothpastes. Indeed, no toothpaste actually whitens. All toothpaste can do is remove stains from the surface of a tooth. And according to a recent survey by Consumer’s Union, the best toothpaste for removing stains was one of the cheapest on the market. Ultrabrite All in One Advanced Whitening performed the best when tested on artificial stains applied to cows’ teeth. And it contains no peroxide!
Claims about controlling the buildup of tartar on teeth bear up more favourably under scientific scrutiny. Tartar is the yellowish hard material that builds up on a tooth as a result of inefficient cleaning. It doesn’t decay teeth, but its presence is a sign that decay is occurring. That’s because when plaque, a mix of bacteria and bacterial byproducts, hardens, forms tartar. And plaque does cause tooth decay! This happens when bacteria feed on food particles and produce acids which leach calcium from teeth. It is this demineralization process that results in cavities. The leached calcium forms calcium phosphate, which deposits on the enamel and hardens into tartar. Once formed, it can only be removed by scraping away. But sodium pyrophosphate in tartar-control toothpaste can prevent its buildup. Pyrophosphate reacts with the calcium that has been leached from teeth to form calcium pyrophosphate, which is water soluble and can be rinsed away. The real key to preventing decay and tartar formation is to get rid of plaque. Proper brushing probably matters more than which toothpaste is used, but some, like Colgate Total, contain the antibacterial agent, triclosan, which may be helpful. And using a toothpaste that contains fluoride is a good idea because fluoride does get incorporated into the tooth and reduces the rate of demineralization. People who have sensitive teeth can look for strontium chloride or potassium nitrate, both of which block pain causing nerve signals. So teeth still cannot be whitened with toothpaste, but we have certainly come a long way from using ground up mouse bones to clean our teeth.