Acid Attack

To understand the process of tooth decay, you might have to remember some high school chemistry and learn how it affects the decay process.

When we eat carbohydrate, the bacterial plaque produces acid which starts to weaken the tooth enamel.  Although enamel is the hardest substance in the body, eventually the acids will dissolve out the minerals, and then destroy the framework that holds them, causing a cavity.  The acid level is measured in a unit called the “pH”.

A neural pH is a 7, with lower numbers, down to 0 are acids and higher numbers up to 14 being bases.  Eating foods with low pH will assist the bacteria in weakening the enamel.  So what are the pH levels of some common liquids?  Water is a neutral 7, as is sugar water.  Add carbonation and the pH drops to 5.1.  Milk is in between at 6.8.  Orange juice, with it’s natural citric acid is about 3.6 while a popular “thirst quenching” drink is 3.1.  Diet cola comes in at 3.0, a popular energy drink is 2.7, and the most popular cola drinks are 2.3, not far above vinegar at 2.2 and stomach acid at 2.0!

The more often we bathe the teeth in acid, the weaker the enamel gets, and the more prone it can be to bacterial damage.  It makes sense to limit the number of exposures of the acid drinks in a day.  Have them with a meal so the acid is buffered by food, and don’t sip on them between meals.

Since we all ingest some acids at meals, the enamel is somewhat weakened.  This reverses with normal contact with saliva and natural minerals.  It’s recommended that you not brush immediately after a meal, but wait a half hour for this re-mineralization to occur.

Dental decay has multiple causative factors.  Bacterial plaque that is not removed from teeth, the acquired type of bacteria in the mouth, the addition of an acid from food and drink, and the frequency of sugar intake will all increase the likelihood of dental decay.  The more of these factors you can control, the better the preventive level you will maintain.