96 American Dental Association 64. Where can valid, evidence-based information about water fluoridation be found on the internet? Answer. There are many reputable sites on the internet that provide information on fluorides and fluoridation including the American Dental Association as well as other reputable health and science organizations and government agencies. These sites provide information that is consistent with the best available scientific evidence. Fact. One of the most widely respected sources for information regarding fluoridation and fluorides is the American Dental Association’s (ADA) Fluoride and Fluoridation website at www.ADA.org/fluoride. (See Figure 6.) From the ADA website individuals can link to other fluoridation websites such as: • Centers for Disease Control and Prevention at www.cdc.gov/fluoridation • The Community Guide at https://www.thecommunityguide.org • Fluoride Science at http://fluoridescience.org The internet contains numerous sources of information on fluoridation. However, not all “science” posted on the internet is based on scientific fact. Searching the internet for “fluoride” or “water fluoridation” directs individuals to numerous websites. Some of the content found in the sites is scientifically sound. Other less scientific sites look highly technical, but contain information based on science that is unconfirmed or has not gained widespread acceptance. In many cases, the information is largely opinion. While everyone is entitled to their opinion, they are not entitled to make that opinion appear as scientific fact. Commercial interests, such as the sale of water filters, are often promoted. Today’s technology can put the world at your fingertips but search engine technology can influence what is returned in searches. The first time the search for “fluoridation” is made, it is likely that the returns will include both pro- and anti- fluoridation websites. When you click to view a website, the search engine takes note and on subsequent searches for the same term, the search engine will return items similar to what you chose initially. For example, if you choose a pro- fluoridation website initially, the next time you search for “fluoridation,” the search engine will likely return a selection of other pro-fluoridation websites for your review. Of course the converse is also true. Clicking on anti-fluoridation websites will allow you to see a search ladened with similar anti-fluoridation sites. Treating Correlation as Causation: Many people have heard the phrase that “correlation does not imply causation.” In other words, just because two events seem to fluctuate in tandem does not prove that they are meaningfully related to one another. For example, statistics show that sales of ice cream increase in warm summer months. Statistics also show that crime goes up in large cities in the summer. However, it would be ludicrous to draw the conclusion that ice cream causes an increase in crime. Yet this is exactly the type of logic exercised in some arguments and studies promoted by those opposed to fluoridation. For example, the opposition often points to Kentucky as having a large portion of the population on public water supplies receiving fluoridated water. And that’s correct. In 2014, Kentucky was ranked the number one state in the U.S. as 99.9% of its public water systems were fluoridated. But the opposition also points to the fact that Kentucky suffers from a large number of people who have lost their teeth. They draw the conclusion that this proves fluoridation does not work — without looking at other factors that influence this outcome. For example, while there is a large number of public water systems that are fluoridated, Kentucky has a large rural population that does not have access to public water supplies. Additionally, and perhaps most importantly, Kentucky’s population has a high rate of tobacco use which is known to be a risk factor for periodontal (gum) disease which can lead to the loss of teeth.