Enamel Erosion Causes

Identifying some of the causes and mechanisms of enamel wear

Although enamel is harder than any other substance in the body, over time it can gradually wear away. Here we explore the causes and mechanisms of enamel wear.

Enamel erosion: demineralisation and remineralisation cycles

Enamel is equipped to respond to normal daily acid exposure. Brief periods of acid exposure trigger a demineralisation process that reduces the mineral density of the enamel surface, thereby weakening it.^1,2Due to mineral-rich saliva, the enamel undergoes a natural process of remineralisation to restore its mineral density and the enamel is strengthened again.^1,2Frequent exposure to acids, especially over long periods, can cause the remineralisation process to become overwhelmed, leaving enamel weakened. In this state, enamel is at risk of irreversible wear.^1,2

Demineralisation and remineralisation after acid challenge

5-minute acid challenge

Enamel demineralisation and remineralisation cycle after 5-minute acid challenge

In vitro SEM images of enamel cross-sections show variations in mineral density³

SEM, scanning electron microscope
20-minute acid challenge

Enamel demineralisation and remineralisation cycle after 20-minute acid challenge

In vitro SEM images of enamel cross-sections show variations in mineral density³

SEM, scanning electron microscope

Enamel wear is a progressive condition

Enamel wear is most commonly caused by a combination of chemical agents and physical wear.

Dietary acidic exposure results in the loss of calcium ions from the enamel surface layer.^4,5 This softens the tooth surface, leading to an increased susceptibility to mechanical abrasion such as tooth brushing.^4,5

Attrition, abrasion, erosion and abfraction can all lead to enamel wear. Factors that increase the risk of enamel wear include:^4–6

Frequent consumption of acidic foods and drinks
Dietary habits, such as swilling drinks or snacking
Gastric reflux or frequent vomiting
Tooth grinding (bruxism)
Acidic medication

Infographic adapted from Lussi et al. 2006⁴

Enamel erosion in patients is partly caused by the wearing effects of acidic food and drink

Modern diets bring increasing challenges to enamel^7–9

Frequent intake of acidic or sugary foods reduces the mouth’s natural environment from a neutral pH of 7. This drop in pH becomes critical when it falls below a pH of about 5.5, leaving the teeth more at risk of enamel wear (acid erosion).⁷