Decrease in demineralization

Increase in remineralization during development

Inhibition of bacterial activity in dental plaque.

The Centers for Disease Control and Prevention published a report on the supposed benefits of fluoride, pulling data from thirty sources circa 1966-1994, including some conducted by the organization itself. The CDC found that for children aged 12, the mean number of decayed, missing, or filled permanent teeth dropped from 4.0 in 1966-1970 to 1.3 in 1988-1994.

They also found that the effectiveness of fluoride ranged from reduction rates of 50% to 70%.

Cost Effectiveness

The CDC also reviewed the cost effectiveness of fluoridated water for cavity prevention and found that in communities with populations greater than 50,000 the mean is 31 cents per person. In communities with less than 10,000, the mean is $2.12 per person. This makes water fluoridation the most cost effective preventative measure for dental health.

Effectiveness on Public Health

A study done by Matthew Neidell, Karin Herzog, and Sherry Glied aimed to find out CWF efficacy at various stages in life and its relation to adult tooth loss. The researchers used 1995-1999 data from the Behavioral Risk Factor Surveillance System, attributed to the CDC, as well as the 1992 Water Fluoridation Census. Using this data, they estimated the interval regression models that relate CWF exposure to tooth loss. From 1960-1980, and 2000 City and County Data Books (CCDBs), they also included other variables to account for area demographics: family income, population, age distribution, racial distribution, and mortality rate. Their results indicate CWF levels in county of residence at the time of an individual's birth are significantly related to tooth loss.

Limitations of this study are the assignment of fluoridation exposure, instead of ideally analyzing by water districts, this study had to use county wide data, the assigning of historical status to a respondent based on the current county of residence; individuals may not have lived there for their entire lives, potential confounding for unobserved factors correlated with fluoridation status with correlating oral health (wealthy may have better access to better dental care), and that it is based on tooth loss and not the full range of impacts on oral health.

Nonetheless, this data concludes that the impact for CWF is epidemiologically advantageous.

The study found that for every four individuals currently living in a county that fluoridated at their times of birth, one individual had one more tooth than if those individuals had not lived in a county that fluoridated. The impact of CWF exposure was also found to be larger for those of lower socioeconomic status.

This presumes that the benefits of water fluoridation may be larger than emphasized, especially for those with ethnic differences and economic disparities. More studies, however, definitely need to be done to fully understand this particular impact and evaluate its accuracy.

Sources

1. Achievements in Public Health, 1900-1999: Fluoridation of Drinking Water

to Prevent Dental Caries. (1999). Morbidity and Mortality Weekly Report, 48(41), 933-940.

'2. Neidell, M., Herzog, K., & Glied, S. (2010). The Association Between

Community Water Fluoridation and Adult Tooth Loss. American Journal Of Public Health, 100(10), 1980-1985. doi:10.2105/AJPH.2009.189555

Image courtesy of Rodney Street Dental