Final answer:
Fluoride's main role in the oral cavity is to prevent demineralization and enhance remineralization of tooth enamel, transforming it into fluorapatite, which is more resistant to acid attacks.
Step-by-step explanation:
Fluoride's main influence in the oral cavity is through preventing demineralization/enhancing remineralization. Fluoride, a key component in toothpaste and often added to tap water, becomes incorporated into the hydroxyapatite of tooth enamel. This reaction transforms hydroxyapatite into fluorapatite, a substance more resistant to acid attacks from oral bacteria. Consequently, fluoride aids in rebuilding and strengthening enamel, which is pivotal for cavity prevention. While fluoride does have a bacteriostatic effect, slowing the growth and multiplication of bacteria, its primary role in dental health is maintaining and restoring the mineral composition of teeth, effectively reducing the incidence of dental caries.