Intrinsic sugars are naturally occurring sugars, such as those found in plants, whereas extrinsic sugars are sugars that are added to foods. The categorization of these two types of sugars was first introduced in 1989 by the United Kingdom Department of Health committee, according to a report by the Food and Agriculture Organization of the United Nations.
Extrinsic sugars can also be divided into the additional categories of lactose, or milk sugars, and non-milk sugars, which are the sugars and honey added to milk. Intrinsic sugars are primarily found in fruits and vegetables.
Research has shown that both intrinsic and extrinsic sugars affect dental health, as tooth plaque ferments these sugars into acid. The acid then dissolves tooth enamel, potentially contributing to tooth decay. The present bacteria continues to go through this process for 20 to 30 minutes after consumption, as stated by the European Food Information Council.
To prevent tooth decay, perform proper oral hygiene practices regularly, which includes the use of fluoridated toothpaste, and eat a balanced and healthy diet with lower sucrose intake.
The terms extrinsic and intrinsic are not widely used for classification of sugars, and the different types are not typically treated or measured differently in regards to their impact on dental health.