If you thought you were doing your teeth a favor by drinking orange juice instead of soda, you may need to think again. Acid, along with sugar, in soft drinks as well as orange juice may erode tooth enamel. But soft drinks and orange juices aren't the only culprits; a number of juices also have the potential to damage tooth enamel and increase your chance of developing cavities.
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Tooth Enamel Characteristics
Tooth enamel, which consists mostly of calcium salts, is the hardest substance in your body, according to Dentalfind.com. Proteins called enamelins and amelogenin make up the hard enamel layer, which protects the dentin inside. Mature enamel does not contain cells and resists bacteria since it isn't alive. "New" teeth such as those in children and young adults do not have strong enamel and are more likely to be damaged by acids produced both by sugar breakdown and by acidic drinks such as orange juice.
Acidity and Enamel
Any liquid with a pH of 7 is neutral, neither acid nor alkaline. Water fits into this description. Any liquid with a pH of less than 5.5 can damage tooth enamel by causing demineralization. A difference of one unit change in pH equals a 10-fold difference in a liquid's acidity, according to 21st Century Dental in Texas. Demineralization, or loss of tooth material, begins at a pH of 5.5. Acidic beverage will decrease the hardness of enamel and increase roughness of the enamel surface, making it easier for food to get trapped in the nooks and crannies and cause tooth decay. Orange juice has a pH of between 2.8 and 4.19, depending on where it came from and the brand.
Orange Juice Acidity Comparison
The lower the number, the more acidic a substance is. Compared to orange juice, cranberry, lemon and lime juice all have lower pH, ranging from 2 to 2.6. Most colas; apple, pineapple and grapefruit juices; and teas have a pH ranging from 2.5 to 4. Orange juice also has a high sugar content; sugars feed bacteria found in plaque that builds up on tooth enamel. As bacteria break down the sugar, they produce a by-product with a high acid content, which further damages the tooth enamel. Orange juice is also high in sugar, which converts to acid in the mouth, and contributes to tooth decay according to a report from Elmhurst College.
You don't have to avoid OJ for the rest of your life because it has a high acid content. You can take measures to ensure the acid -- as well as the sugar -- doesn't sit in your mouth or on your teeth for longer than necessary. Sipping a drink slowly over 20 minutes gives acid more chance to damage your teeth than drinking quickly, dentist YanFang Ren of the University of Rochester Health Center explains in an interview with "Science Daily." Drinking through a straw also helps keep orange juice and other acidic drinks away from teeth. Swish water around in your mouth after drinking orange juice. Having your teeth sealed with a protective coating helps keep acid off the enamel on the molars. Using a fluoride-based toothpaste to brush twice a day and having a fluoride treatment once a year also fights tooth enamel decay.