The Dangers of Acidic Drinks

In my career I see more and more often patients presenting with little holes on the chewing side of their back teeth. This is a clear sign of acid erosion.

Erosion is the loss of tooth enamel by acid attack. The enamel is the hard outer layer of the tooth, the inner layer, which makes the bulk of the tooth, is softer and is called dentine.

When we eat or drink anything acidic we inadvertently soften the enamel and our teeth lose minerals. Over time the saliva neutralises the acids and restores the balance in the mouth. But, after drinking acidic drinks it takes a full hour for our teeth to fully recover their protection. 

More often than not though, we tend to graze at food or drink, especially in an office job which means that there is not enough time for the saliva to replace the minerals before we eat or drink something else damaging, exacerbating the problem.

As the enamel loses minerals, it starts to become vulnerable. The pattern of acid erosion is clear, it starts as pot holes, usually on the chewing surface of the back teeth. Over time this can develop into bigger cavities until ultimately the dentine is exposed.

This makes the tooth more prone to decay as there is no enamel to offer protection. You can see in the photo a molar tooth of one of my patients who has lost most of their enamel to fizzy drinks.
I am concerned about the amount of acid we eat and drink every day in out diet. Although the damage that acid intake can cause to teeth has been well documented, I still feel people don’t really understand the risks of drinking acidic drinks. After school I see a lot of kids walking passed the surgery with bottles of fizzy drinks half full in their hands. Fizzy drinks and juices are well known for causing acid erosion to our teeth. These, in combination with the sugars in the modern diet, and generally deficient brushing, create the perfect storm in terms of decay.

So how do we know what is an acidic drink? When we measure whether a substance is acidic, neutral or alkaline/basic we use a scale called pH.
The neutral pH is 7, anything below 7 is considered acidic and anything above the neutral pH is alkaline. When we understand how bad/dangerous a drink is for our teeth, we recognise the importance of knowing the critical pH for our teeth. The critical pH is the point at which the tooth will dissolve.

The outer layer or enamel, dissolves at a pH below 5.5 and the inner layer, dentine dissolves at a pH below 6.5. Each whole pH value below 7 is ten times more acidic than the next higher value. For example, a pH of 4 is ten times more acidic than a pH of 5 and 100 times (10 x 10) more acidic than a pH of 6. The pH of the acid in dental plaque is 4; therefore it will dissolve enamel.

In order to protect our teeth, we should not eat or drink anything whose pH is below 5.5, certainly not frequently. So it is important to understand the pH of our drinks, below are some examples:

PRODUCT - pH

Evian Water - 8.10

Saliva - 7.40

NEUTRAL pH - 7.00

Dentine dissolves below - 6.50

Black Coffee - 5.70

Enamel dissolves below - 5.50

Budweiser - 4.38

Tropicana 100% Apple Juice - 4.05

Orange Juice - 3.70

Red Wine - 3.59

Red Bull - 3.37

Sprite - 3.29

Diet Coke - 3.28

Welch’s Grape Juice - 3.24

Coke Zero - 3.18

Gatorade Lemon - 3.07

Diet Pepsi - 3.03

Fanta Orange - 2.73

Pepsi - 2.53

Coca-Cola - 2.52

Lemon - 2.29

Lime - 2.17

Stomach acids - 1.50 – 3.50

What should I do to protect my teeth? Here are my top tips:

1. Limit acids and sugars in your diet
2. Eat cheese – this helps to neutralize the acids – cheese and wine has some science behind it!
3. Don’t brush your teeth straightaway – as the enamel is soft you’ll brush away some of the enamel.