Carrie is being examined by her dentist, who notices that she has many cavities (caries). When she tells him about her dental regimen, he explains to her that she doesn't brush her teeth often enough to remove the bacteria that ________, which is why she has so many cavities.

Question

Quizplus · Accepted Answer

The bacteria that naturally live in the mouth metabolize carbohydrates in food to produce acidic by-products. These acids, if not removed by brushing, will damage the enamel and dentin of the teeth, leading to cavities. Choice A is incorrect because gum infection (gingivitis) is caused by a build-up of plaque, a different bacterial by-product. Choice B is incorrect because destruction of the gums is not directly related to the formation of cavities. Choice D is incorrect because bacteria do not secrete acids directly onto the teeth.

Carrie Is Being Examined by Her Dentist, Who Notices That