The primary organic acid found in apple juice is malic acid, but it also contains small amounts of various other natural acids, including phosphoric, citric and quinic acids. According to the Oklahoma State University Cooperative Extension Service, the acid content of apple juice gives it a median pH value of 3.7, qualifying it as a high-acid beverage. While it’s commonly understood that the regular consumption of sugary foods and beverages increases the risk of dental decay, consuming acidic foods and beverages can also compromise mouth health through the erosion of tooth enamel, which can lead to soft, sensitive teeth, yellowing and further decay.
When you drink a beverage that has a low pH value, it temporarily softens your tooth enamel until your saliva restores the acid-base balance in your mouth. Regular consumption of high-acid beverages can prevent your mouth from maintaining its natural level of acidity, according to the Academy of General Dentistry. This increases your risk of dental erosion, or the loss of tooth enamel by a chemical process that doesn't involve bacteria. High-acid beverages are major contributors to the development and progression of dental erosion. According to the American Dental Association, the total acid amount and type of acid in a beverage, as well as its exposure time in the mouth, are important factors in determining how erosive a beverage is.
The pH value is a significant factor in determining a beverage’s erosive capacity. However, certain types of acids are more erosive than others. A 2001 report by the American Dental Association states that phosphoric acid, a common component of soft drinks, is very erosive in drinks with pH values below 2.5, but less erosive in drinks with pH values of 3.3 or higher. According to the same report, tartaric, citric and malic acids are especially erosive, in part because they bond to calcium at higher pH levels. Apple, orange and grapefruit juice, lemonade, diet and regular soft drinks, decaffeinated and regular coffee, sports drinks and white wine can all contribute to dental erosion when consumed on a regular basis.
If apple juice or any other acidic beverage is a regular part of your diet, you can take steps to minimize your risk of damaging your teeth. Use a straw to keep the contact between the juice and your teeth minimal. Don’t hold the juice in your mouth or sip your drink over a long period of time. Instead, drink quickly to limit the exposure of your teeth to the acids in the juice. Chewing sugar-free gum afterward stimulates the flow of saliva, which helps dilute and neutralize acids. A 2013 "Wall Street Journal" report recommends using anti-bacterial mouthwash immediately after drinking acidic juice, or waiting 30 minutes to brush your teeth after consuming an acidic beverage, because the acids soften the enamel and immediate brushing can actually cause damage.
Dental erosion is irreversible and can lead to the structural damage of your teeth. Early indications of thinning enamel include pain or sensitivity to hot or cold foods and beverages. Desensitizing toothpaste with a neutral pH can help reharden the remaining, softened enamel, according to an article by the Academy of General Dentistry published on the website ScienceDaily. Limiting your consumption of apple juice and other acidic beverages is one of the best ways to reduce your risk of dental erosion. You needn’t eliminate healthful, acidic foods and beverages from your diet, however -- practicing good dental hygiene also minimizes your risk of damage to your teeth.