Comment by saberience

Just a note for future people reading this comment. This is completely and totally wrong, and arguably should be deleted from Hackernews for being so deluded.

There have been countless studies that show that communities with flouride in the water have consistently lower rates of tooth decay than communities without fluoride in the water. In fact, community water fluoridation has been recognized as one of the great public health achievements of the 20th century.

Systematic reviews and meta-analyses have shown repeatedly that water fluoridation reduces tooth decay in both children and adults by approximately 25-30%.