Acid Erosion

Our teeth are covered in the hardest and most highly mineralised substance in our bodies: enamel. The enamel is formed by cells called ameloblasts which are only active during tooth development. Enamel contains no living cells therefore we cannot regenerate it. It is a crystalline structure which contains minerals, primarily hydroxyapatite.

Our bodies are amazing. They can heal cuts and knit together broken bones. However, one thing we cannot do is make more enamel or restore damaged enamel.

Enamel damage can be caused by many factors:

  1. Higher than optimal temperatures during tooth development e.g. if you had a high fever as a small child.
  2. Gastrointestinal problems such as frequent vomiting or acid reflux.
  3. Retention of food debris between the teeth

The pH of our mouths is approximately 7.5pH, and enamel is damaged when the pH of our mouths drops below 5.5pH.

The Stephan Curve (below), first described by Robert Stephan in 1943, shows the fall in pH below the critical level (5.5pH) at which enamel demineralisation occurs following the intake of “fermentable carbohydrates” i.e. acidic liquids and sugars, in the presence of acidogenic bacteria which are present in our mouths.

The Stephen CurvepH Levels

level of acidity

What is acid erosion?

The pH of our mouths changes when we eat or drink. When we consume acidic foods/drinks the pH can fall below 5.5, and this is when our enamel begins to demineralise. Our saliva plays a fantastic role in remineralisation as it contains minerals which can repair acidic damage to our enamel.

When we give saliva a chance, it repairs the damage done by acids. This means we have to remove food from on and, more importantly, in between the teeth. If we allow food to remain on or in between our teeth, bacteria utilise this. They grow, multiply and produce acids as a by-product, and it is these acids that cause damage to our enamel.

If you have acid erosion you may:

  • Feel pain or sensitivity when consuming hot, cold, sweet or acidic drinks
  • Notice a yellowish discolouration of the teeth
  • Face greater risks for more cavities over time

What can you do to prevent acid erosion?

  • Remove food from in between teeth by using floss/tape/interdental brushes
  • Ideally wait 60mins after eating before brushing your teeth OR at least chew sugar-free gum after eating. This stimulates saliva production which neutralises the acidic phase after eating and facilitates the repair of the enamel
  • Spit out excess toothpaste after brushing but do not rinse with water or mouthwash
  • Limit acidic/sugary foods and drinks to mealtimes. This will limit the frequency of acid attacks on your teeth
  • Use a straw when drinking acidic/sugary drinks
  • Finish a meal with cheese or milk to help neutralise acidic action


Fluoride-containing toothpastes also aid enamel remineralisation by incorporating fluoride from the toothpaste into the tooth structure, making it more resistant to acid erosion.

Children up to 3 years old should use a toothpaste with a fluoride level of at least 1000ppm (parts per million). 3 year olds up to adults should use toothpaste that contains 1350ppm to 1500ppm.

There is a lot we can do to lessen the effects of acid erosion. One of the main things we can do is to remove food debris between our teeth. By doing this we allow our saliva to perform its fantastic role of repairing the damage caused. We can also limit our intake of sugary/fizzy/acid foods and drinks to mealtimes.

If you think you might have acid erosion, you can ask your dentist for advice.


Written by Miss Faye Law
Senior Dental Nurse at The Keith Dental Practice
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