Tooth erosion occurs when acid wears away tooth enamel, which is the glossy, protective outside layer of the tooth. Without the protection of enamel, teeth are more susceptible to developing cavities, as well as becoming sensitive, cracked, and discolored.
Beverage consumption in most developed countries of the world is now a major contributor of tooth decay. Many sodas and diet soft drinks approach the pH level of battery acid in terms of corrosiveness and erosion of tooth enamel. Our susceptibility to tooth decay and cavities has much more to do with what we put in our bodies, rather than regular visits to our dentist or even how often we brush our teeth. If you want to prevent tooth decay, a 'great' idea is to stay away from acidic beverages which dissolve tooth enamel and offer no nutritional value to your body.
The General Dentistry case study compared the damage in three individuals' mouths -- an admitted user of methamphetamine, a previous longtime user of cocaine, and an excessive diet soda drinker. Each participant admitted to having poor oral hygiene and not visiting a dentist on a regular basis. Researchers found the same type and severity of damage from tooth erosion in each participant's mouth.
"Each person experienced severe tooth erosion caused by the high acid levels present in their 'drug' of choice -- meth, crack, or soda," says Mohamed A. Bassiouny, DMD, MSc, PhD, lead author of the study.
The Problem with Citric Acid
Here's an ingredient to look out for when you check ingredient lists. Excessive consumption of foods and beverages that contain citric acid can contribute to erosion of tooth enamel. Citric acid is an organic compound that is often used as a preservative in canned and frozen foods. It is also used to flavor soft drinks and certain foods. Some amount of citric acid is naturally present in many fruits and vegetables. But regardless of the source, too much citric acid can be hard on the teeth.
The citric acids in fruits and carbonated soft drinks dissolve the calcium salts that make up the surface of teeth. When the surface of a tooth becomes decalcified and soft, plaque forms and erodes tooth enamel. Teeth stripped of enamel are brittle and sensitive to pain. Furthermore, once enamel breaks down, bacteria can invade and cause decay.
Researchers at the University of Iowa's College of Dentistry found that energy drinks and sports drinks, such as Gatorade and Red Bull, eroded the enamel more than soda and fruit juices. In a 2008 study published in the journal Nutrition Research, the dentists soaked extracted human teeth in various liquids for 25 hours, and then measured the structural changes, or lesions. "Power drinks can be quite acidic, usually because there is an addition of citric acid to those to give it tartness that is desired by some consumers," said Dr. Clark Stanford, the associate dean for research at the University of Iowa College of Dentistry. "It's important to look at the label and see if citric acid has been added."
Carbonated soda drinks create a double whammy on your teeth. This is because, in addition to all the sugar in them, they also contain very acidic ingredients, like phosphoric acid in sodas, and citric acid in citrus flavored drinks. The carbonation water is itself mildly acidic. All this extra acid makes the acid concentration on your teeth even greater than what you normally get from the sugar fermented by bacteria. The result is that your teeth may decay and develop cavities even faster. Are these drinks worth the double risks of tooth decay and diabetes?
"The citric acid present in both regular and diet soda is known to have a high potential for causing tooth erosion," says Dr. Bassiouny.
The individual who abused soda consumed 2 liters of diet soda daily for three to five years. Says Dr. Bassiouny, "The striking similarities found in this study should be a wake-up call to consumers who think that soda -- even diet soda -- is not harmful to their oral health."
Prolonged exposure to soft drinks can lead to significant enamel loss, even though many people consider soft drinks to be harmless or just worry about their sugar content and the potential for putting on pounds.
The erosive potential of colas is 10 times that of fruit juices in just the first three minutes of drinking, a study showed. The research, published in Academy of General Dentistry (AGD) journal General Dentistry, reports that drinking any type of soft drink hurts teeth due to the citric acid and/or phosphoric acid in the beverages.
Non-colas are less acidic than colas overall, the study found, but they erode the teeth more effectively than colas.
The University of Ottawa has shown that sugars, bacteria and acidity levels of foods and beverages are all contributors to cavities. Tooth enamel begins to dissolves at 5.5 pH and you progress down the scale, erosion increases. The safest beverage for tooth health is pure water.
AGD Spokesperson Eugene Antenucci, DDS, FAGD, recommends that his patients minimize their intake of soda and drink more water. Additionally, he advises them to either chew sugar-free gum or rinse the mouth with water following consumption of soda. "Both tactics increase saliva flow, which naturally helps to return the acidity levels in the mouth to normal," he says.
AGD spokesman Kenton Ross said that RC Cola was found to be the most acidic soft drink studied, with a pH of 2.387 (the pH scale ranges from 0 to 14 for most liquids, with 0 being the most acidic and 14 being the least acidic--or most alkaline). Cherry Coke was found to be the next most acidic (pH of 2.522), and Coke was the third most acidic soda tested (pH of 2.525).
Battery acid has a pH of 1.0. Pure water at room temperature has a pH of 7.0.
Natasha Longo has a master's degree in nutrition and is a certified fitness and nutritional counselor. She has consulted on public health policy and procurement in Canada, Australia, Spain, Ireland, England and Germany.