Which statement reflects understanding of fluoride's role in preventing dental caries?

• A. Excessive amounts of fluoride will make teeth turn brittle and yellow.
• B. Having our children brush with fluoride toothpaste is not effective.
• C. Use of fluoride in water is mostly effective during initial tooth formation.
• D. Dental caries can be prevented through fluoridation of public water.

Answer: (D)

Fluoride protects teeth by both strengthening enamel as it forms and aiding remineralization after eruption, and water fluoridation provides a steady, low level of fluoride that helps reduce decay across the whole population. The statement that dental caries can be prevented through fluoridation of public water captures this broad, ongoing protective effect: it benefits teeth during development and continues to help prevent decay in teeth that have already erupted. This is supported by evidence showing lower caries rates in communities with optimally fluoridated water, especially when combined with fluoride toothpaste and other topical fluoride sources.

Other ideas miss the mark in important ways. Excess fluoride can cause fluorosis, not simply teeth becoming brittle and yellow in all cases. Fluoride toothpaste is effective when used properly, so dismissing its impact isn’t accurate. And fluoride in drinking water provides protection beyond initial tooth formation, helping teeth throughout life, not just during early development.