Britannica
Sources used in this answer
How do bacteria in dental plaque damage enamel and dentine?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
tooth
Cross section of an adult human molar.
Bacteria in dental plaque—a mass of bacteria and sticky polymers—damage teeth through the metabolism of ingested sugars and fermentable carbohydrates.12
When bacteria, such as Streptococcus mutans, metabolize these substances, they produce acidic metabolites, including lactic acid and acetic acid. These acids dissolve and eat away the enamel, which is the hard outer surface of the tooth.12
Once the decay progresses past the enamel into the dentine, the damage continues through a combination of enzymatic action and direct bacterial invasion, which destroys the protein structure of the dentine. Because plaque shields these bacteria from saliva and the tongue, it facilitates the ongoing production of these destructive acids.12