Whilst the fact that a certain number of professionals oppose or support measure X, Y or Z does not automatically constitute a valid argument one way or another, it is always worth noting when professional or expert voices have something detailed to say on a matter. Their arguments should at the very least be taken seriously and aired appropriately.
Since its inception, water fluoridation has been opposed by numerous well-qualified individuals and this continues into the present day. However, the media frequently neglects to mention the arguments put forth by such individuals and instead focuses on the rantings of unqualified fringe conspiracy nuts. The unfortunate consequence is that anyone who raises valid scientific or ethical objections to water fluoridation is automatically dismissed.
The idea that opponents of fluoridation do not have professional qualifications is blatantly incorrect:
"Some opponents of fluoridation do not have professional qualifications (of course); many do. Many highly qualified doctors, dentists, and scientists have opposed fluoridation in the past and do so today" .
"Some of the earliest opponents of fluoridation were biochemists. One of those early opponents was one of the world's leading authorities on enzyme chemistry, Nobel laureate Dr. James Sumner at Cornell University. He said: "We ought to go slowly. Everybody knows fluorine and fluorides are very poisonous substances... We use them in enzyme chemistry to poison enzymes, those vital agents in the body. That is the reason things are poisoned; because the enzymes are poisoned and that is why animals and plants die." Dr. James Sumner was one of at least 12 Nobel Prize winners in Chemistry and Medicine, who have either opposed fluoridation or expressed reservations about it. These include Giulio Natta (1963 Nobel Prize in Chemistry), Nikolai Semenov (Chemistry, 1956), Sir Cyril Norman Hinshelwood (Chemistry, 1956), Hugo Theorell (Medicine, 1955), Walter Rudolf Hess (Medicine, 1949), Sir Robert Robinson (Chemistry, 1947), James B. Sumner (Chemistry, 1946), Artturi Virtanen (Chemistry, 1945), Adolf Butenandt (Chemistry, 1939), Corneille Jean-François Heymans (Medicine, 1938), William P. Murphy (Medicine, 1934), and Hans von Euler-Chelpin (Chemistry, 1929). This listing makes absurd the ADA's claim that there is "no scientific debate" over this issue and that the only people who oppose it are 'crackpots'" .
Consider the example of Dr. Sumner's cautionary warnings (cited above) in light of the following 2010 extract from the journal, Chemico-Biological Interactions:
"Halfway through the twentieth century, fluoride piqued the interest of toxicologists due to its deleterious effects at high concentrations in human populations suffering from fluorosis and in in vivo experimental models. Until the 1990s, the toxicity of fluoride was largely ignored due to its "good reputation" for preventing caries via topical application and in dental toothpastes. However, in the last decade, interest in its undesirable effects has resurfaced due to the awareness that this element interacts with cellular systems even at low doses. In recent years, several investigations demonstrated that fluoride can induce oxidative stress and modulate intracellular redox homeostasis, lipid peroxidation and protein carbonyl content, as well as alter gene expression and cause apoptosis. Genes modulated by fluoride include those related to the stress response, metabolic enzymes, the cell cycle, cell-cell communications and signal transduction" .
It is therefore obvious that Dr. Sumner knew something that modern fluoridation promoters would prefer not to have mentioned in their well-funded public relations campaigns promoting the extension of water fluoridation programs.
So the next time someone tries to automatically dismiss your arguments on the basis that you have no professional support, let them know that many legitimate professionals – past and present  – actually agree with you. This alone should make them re-think their position. Furtheremore, don't forget to mention that these professionals have been willing to outline their arguments in sworn affidavits [5-6] and in many other ways for the public record.
 A Response to Pro-Fluoridation Claims, p. 252