When I was a kid growing up in Tucson- it seemed like we lived at the dentist- and getting cavities filled was routine.  It’s way better these days because of a host of public health and dental product interventions…  but 75% of Arizona kids still have tooth decay by the time they’re in 3rd grade.

Around 1900 scientists speculated that fluoride might protect against tooth decay based on observations that different communities had different trends in tooth decay.  They didn’t exactly know that it was fluoride, but noted that fewer cavities were present in communities where folks had mottled teeth (now called dental fluorosis) which we now know is caused by high levels of fluoride.  Researchers in the 30s and 40s found the direct relationship between fluoride concentrations and tooth decay, and determined that moderate levels of fluoride prevent cavities.  Water fluoridation as a public health intervention began shortly thereafter.

Water fluoridation today reduces cavities by up to 40% relative to communities with low levels of fluoride.  It costs about 95 ¢ per person per year, saves $38 in unnecessary dental costs per person per year… and fluoridating a person’s water for a lifetime costs less than filling 1 cavity!

Some fluoride is naturally present in water and food. Because of our reliance on groundwater for drinking water In Arizona, many communities have naturally occurring fluoride- so all Arizonans get some.  When you hear the word “fluoridation” it basically means that the community adds enough fluoride to the water to bring the natural level up to the amount needed to prevent tooth decay.  Currently, 10 Arizona communities (Bisbee, Chandler, Gilbert, Glendale, Guadalupe, Mesa, Peoria, Phoenix, Tempe, and Yuma) fluoridate their water supply to the right level.  Many other communities in Arizona have naturally occurring optimal levels of fluoride in their drinking water.  Arizonans can check the fluoride levels in their water systems on the My Water’s Fluoride website.  Folks can also learn more about community water fluoridation on the CDC’s fluoride website and on EPA’s fluoride website

We also recommend everybody brush at least twice a day with fluoride toothpaste—when getting up in the morning and before going to bed.  For little kids, we recommend monitoring the amount of fluoride during tooth brushing by supervising and discouraging kids from swallowing toothpaste- and teaching them to only place a pea-size amount of toothpaste on the toothbrush.