How does xylitol prevent tooth decay?

Xylitol effectively prevents tooth decay primarily because bacteria in the mouth are unable to utilize it for acid production. When we consume regular sugars, bacteria metabolize these sugars and produce acid as a byproduct, which can lead to the demineralization of tooth enamel and contribute to the development of cavities.

In contrast, xylitol is a sugar alcohol that, while it may taste sweet, does not trigger the same acid-producing processes in oral bacteria. Instead, when xylitol is present, it can actually inhibit the growth of harmful bacteria, reducing their numbers and, consequently, the amount of acid produced. This reduced acidic environment helps protect tooth enamel from decay.

While the other choices may touch upon relevant aspects of dental health, they do not accurately reflect the primary mechanism by which xylitol aids in preventing tooth decay. For instance, while promoting enamel growth and replacing sugar in the diet can have beneficial effects on oral health, these processes are not the direct reason for xylitol's effectiveness in preventing cavities. Additionally, using xylitol as an abrasive is not its primary role; its effectiveness comes from its inability to be metabolized by decay-causing bacteria.