December 03, 2015
One of the most common complaints dentists get is about dental staining. A patient’s teeth are too grey, too brown, too yellow, or too dull. This cosmetic problem often leaves a smile looking older and unhygienic. In addition to smoking and chewing tobacco, intensely colored foods and drinks are often the most common offenders. The deeper the pigmentation, the more likely the foods and beverages cause staining. Stains come not only from the amount of pigmentation, but also how frequently these substances come in contact with the enamel and for how long. Coffee, as you might imagine, is a huge contributor across the country. But does caffeine in coffee contribute to stains? Or is it something else?
How Extrinsic Dental Stains Occur
The enamel of your teeth, though hard and tough, still has a porous surface. It contains microscopic pits, ridges and fissures that can hold microscopic particles. Intensely pigmented molecules, called chromogens, give foods and beverages their color. These molecules have a nasty habit of getting into pores on the enamel and causing dental stains. Other factors in teeth stains include acidity and food compounds called tannins.
Acidic foods and drinks erode the enamel and temporarily soften teeth. The same thing happens with cavities, when bacteria in the mouth consume simple sugars and produce acid as a byproduct. The acid erodes the enamel and creates weakened areas of teeth where chromogens can latch on more easily. Tannins boost the chromogens’ ability to latch on to enamel, and promote staining in that way. So wine is a triple threat. It is an acidic beverage that is both chromogen and tannin-rich, making it notorious for dental stains. Now coffee on the other hand, contains chromogens, but is low in tannins, so it doesn’t stain as much as wine. As for the acidity of coffee, that depends.
The flavor in coffee relies heavily on the organic acids of the coffee bean. Most regular coffee is made from Arabica beans and decaffeinated coffee is made from Robusta beans, because they retain more coffee flavor after the decaffeination process. The acid content of these beans includes quinic, malic, citric, formic, and acetic acids. The acidity level directly correlates to the maturity of the bean when picked as well as the roasting time. Longer roasting decreases acidity. Typically black coffee rests at a pH value of 5.70. Now, for reference, lemon juice is considered acidic and typically has a pH value of 2.00. Pure water is neutral and has a pH value of 7.00. The lower the pH value, the higher the acidity.
Does Caffeine Contribute to Dental Stains?
Caffeine itself does not cause stains, however it could raise the acidity of the beverages and increase the risk of dental stains in that way. One study by Dionex, a part of Thermo Fisher Scientific, found that regular coffee is more acidic than decaf coffee. However most results show that decaffeinated coffee is in fact more acidic. This is because the Robusta beans used in decaf coffee contain a higher level of caffeine and are more acidic than those used in regular coffee. That said, dental stains from regular and decaf coffee do not likely come from the acidity of caffeine. In fact, coffee contains an alkaloid called Trigoneline. This ingredient helps neutralize the effects of acids produced by bacteria in the mouth. So staining from coffee, decaf or regular, mostly comes from the chromogens that make the beverage look dark.
How to Prevent Dental Stains from Coffee
If you are unwilling to give up your regular morning cup of decaf, then there are a number of things you can do reduce your risk of dental stains. You might try these suggestions: