I've been away for a bit to cool down after the political climate got too hot for me. I am happy to be back. This election did make me acutely aware of how quickly misinformation and fake news spreads.
I love this website. I love vegan-ism. I am excited about the interesting discussions about honey bee sentience and rights. Where else on the web can you find such enlightening and invigorating discussions?
Yet, sometimes as fallible humans we make mistakes due to our cognitive biases.  One mistake I think I have made is in regards to fluoride.
Science vs ideological bias
Why do we need science? To error check and figure out the truth is my answer. Humans make mistakes all the time and as seen by the book Merchants of Doubt professional deceivers make good use of our fallible and often gullible nature.  Btw, I first heard of the book here on this amazing website.
As seen in the book the tobacco industry lied to us just as the climate change denial industry has. We need science to fight against the agents of injustice within the world.
Personally, I have spent much time, energy, and willpower arguing with people who deny science. Whether they be paleos, climate change deniers, or even flat Earth believers.
Yet, why do these science deniers deny science? Well if you take a free course at edx.org you will find out why.  Science denial stems from accepting an idea and then looking for evidence to back up the accepted idea. This is a form of cognitive bias or political bias. True skeptics on the other hand look at the evidence first and then form an opinion based upon scientific fact.
Now, we know why people come to the wrong conclusions. In the case of fluoride it has to do with the naturalistic ideology. I accepted that fluoride did more harm than good because chimpanzees don't use fluoride toothpaste. Yet, I now believe that fluoride toothpaste does more good than harm when following the proper procedure.
We need science to convince others
When I first starting arguing with others on-line, I found I wasn't believed. That's okay, because many people experience the world view backfire effect. Meaning presenting evidence to the contrary of their belief further entrenches said belief. Yet, that wasn't the problem.
The problem was I wasn't convincing the swing voters nor the lurkers reading the thread. Why, because I was an amateur and made inferior arguments. I didn't use sources, when I did use sources my sources were low credibility, and finally I didn't use science.
Imagine a vegan and palo arguing back and forth both firming entrenched in their ideologies. Let's say the argument is about both animal and plant sentience. What would break the stalemate?
Science from a credible source would break the stalemate. If the vegan was to link to this  article and show that bees have 960,000 neurons in their head proving that bees can are smarter and have a higher form of sentience than carrots. Therefore, eating steam carrots is fine, but not honey from enslaved honey bees.
Here's another article showing how smart bees are.  "The stress of shaking had turned them into pessimists who interpreted the ambiguous odor as half-threatening, rather than half-appetizing. " 
In other words bees have an emotional state of sorts. Without science the vegan and palo are essentially gridlocked never progressing just shouting back and forth until one gets tired. The swing voters, the lurkers, are never swayed.
The same can be said for other idealogical arguments. An environmentalist and a libertarian can get in a debate about climate change. Yet, without evidence the argument cannot progress.
Also ideologies can be taken too far. To state that no tree should ever be cut down is going too far, there is sustainable logging techniques. The flip side would be to clear cut every single tree, which would also being going too far, but in the other direction.The solution is in the middle ground based upon evidence, sustainable logging techniques.
Science helps protect ourselves and keep the vegan community safe
Now what does this have to do with fluoride? Personally, I went with the all natural anti-toxin ideology. I got rid of all my ADA approved fluoride toothpaste, I stopped using my ADA approved antiseptic mouthwash, and I stopped using my ADA approved ACT fluoride rinse. Guess what? My teeth got worse.
Now this is only a sample size of one, so I looked into why this was happening? Why suddenly when I drink salt do I get gas and my teeth hurt? Why are my cavities getting worse? Why do my gums often hurt?
Well eventually due to pain and desperation I reverted to my old fluoride and antiseptic ways. Within an hour my pain lessened considerably. Within 24 hours my pain was all but gone only to reoccur occasionally with much less duration and pain.
My teeth have decayed more slowly I feel better and I have more energy. Wait, a minute what happened? I thought toxins were the enemy.
Well I looked into the science using credible sources and guess what? Fluoride is useful after all, apparently the fluoride ion binds with the teeth and makes it more difficult for bacteria to eat your teeth and therefore grow in numbers. My generic brand of anti-septic was killing pathogens that were causing me pain, draining my energy, and damaging my teeth.
In summary we need science to convince others and to keep ourselves safe. If a person mindlessly follows an ideology without evidence he/she will eventually hurt him/herself. To the best of my knowledge fluoride tooth paste and mouthwash are vegan. The same goes with my antiseptic.
Ultimately, advocates of fluoride-free toothpaste probably mean well, but are putting the health of the vegan community and their selves at risk. When the vegan community is at risk animals are at risk. Fluoride-free advocates are putting their own personal purity above the needs of animals.
Now look at the science below and make an evidence and scientific based decision about whether you should use fluoride.
The most important ingredient to look for when choosing toothpaste is fluoride.
Fluoride is a naturally occurring mineral. Its use has been instrumental in the dramatic drop in tooth decay and cavity occurrence that has taken place over the past 50 years. Bacteria in your mouth feed on sugars and starches that remain on your teeth after eating. Fluoride helps protect your teeth from the acid that is released when this happens." 
""Most likely, fluoride works by a combination of these effects. But the remineralization effect of fluoride is of prime importance, because it results in a reversal of the early caries process and it gives rise to an enamel surface that is more resistant to decay." 
With all these amazing benefits of fluoride, why would people resist fluoride?
How Poisonmongers Work
The antifluoridationists' ("antis") basic technique is the big lie. Made infamous by Hitler, it is simple to use, yet surprisingly effective. It consists of claiming that fluoridation causes cancer, heart and kidney disease, and other serious ailments that people fear. The fact that there is no supporting evidence for such claims does not matter. The trick is to keep repeating them—because if something is said often enough, people tend to think there must be some truth to it." 
Since its inception in the 1940s, the scientifically sound concept of fluoridating water has been a source of fear and suspicion in the minds of conspiracy theorists.
Fluoride works by converting the outer layer of tooth enamel made of hydroxylapatite, Ca5(PO4)3OH, to fluoroapatite, Ca5(PO4)3F. The latter chemical is less soluble in acidic solutions. The three most commonly added fluoride chemicals are sodium fluoride (NaF), fluorosilicic acid ((H3O)2SiF6), and sodium fluorosilicate (Na2[SiF6]). Fluorosilicic acid is a byproduct of phosphate fertilizer manufacture, a fact which fluoride opponents repeat ad absurdum in an attempt to scare you.
In short: The issue has been extensively studied since the 40's. As a result, every reputable public health organization endorses the benefits of fluoridation. To date, no such organizations have endorsed claims that fluoride is a secret communist mind-control plot -- though we wait with bated breath." 
"So rest easy gentle readers. No matter how hard we try, we dentists aren’t very good at poisoning you people. In fact all those things we recommend to you actually are beneficial to your dental and overall health and have a long track record of success as well as reams of solid scientific evidence to back up their safety and efficacy. And kudos to the AAP for updating their fluoride recommendations to better protect our young children from dental decay, the number one malady affecting children." 
As for the legitimacy of these sources, due to this being the age of fake news, I highly recommend using mediabiasfactcheck or another credible fact checker for every website you use.
These sources consist of legitimate science or are evidence based through the use of credible scientific sourcing. Legitimate science follows the scientific method, is unbiased and does not use emotional words. These sources also respect the consensus of experts in the given scientific field and strive to publish peer reviewed science. Some sources in this category may have a slight political bias, but adhere to scientific principles. See all Pro-Science sources.
Factual Reporting: VERY HIGH
Notes: Science-Based Medicine is dedicated to evaluating medical treatments and products of interest to the public in a scientific light, and promoting the highest standards and traditions of science in health care. (8/19/2016)" 
Thank you for reading this post. Remember put animal welfare above your own personal purity by keeping the vegan community safe. Stick to science and evidence based practices and ideas. Use fluoridated tooth paste to keep good care of your teeth.