Key Differences Between Caries and Dental Erosion

Generalities can be confusing. Caries is often described as the loss of minerals by the direct action of acids on the teeth, and dental erosion is also defined in a similar way. While both statements are true, of primary importance is the type of acid, where the acid comes from and specific sites on the tooth surface to which these acids are directed. It is important to differentiate enamel damage due to caries vs. damage that results from dental erosion. Both the etiology and symptoms of these two processes differ significantly, as do the appropriate management strategies for each (Table 3).

One major difference between caries and dental erosion needs to be clearly understood. Caries is a process that begins with demineralization and, at early stages, can be reversed, either through the natural process of remineralization or through enhanced remineralization due to fluoride therapy. Dental erosion, on the other hand, is essentially a non-reversible process that results in permanent damage to the tooth structure.

Table 3. Key differences between caries and dental erosion.
Graphic of a tooth. Photo of cavities in teeth. Photo of tooth erosion.
Key Comparisons Cavities Erosion
Type of process Mineral Change Mineral Loss
Tooth site(s) affected Enamel & dentin Enamel & dentin
Primary cause Bacterial acids Dietary acids
Primary site(s) of damage Subsurface, under plaque Exposed, plaque free surface
Conditions Exposure to weak acids for prolonged periods of time, usually at a pH above 4.0 Repeated exposure to dietary or gastric acids, generally below pH 4.0, for short time periods
Result Sub-surface phenomenon with intact outer layer of enamel Surface softening leading to loss of surface mineral
Reversible? Reversible in early stages Irreversible surface loss
Contributing factors Buffering by saliva helps neutralize bacterial acids Saliva and pellicle overwhelmed by dietary and gastric acids
Preferred therapeutic approach Prevention as well as reversal of early damage Prevention is critical for managing
Fluoride effectiveness ------------ ------------
Sodium fluoride Yes Minimal
Sodium monofluorophosphate Yes Minimal
Stannous fluoride Yes Yes