Does the temperature of tap water affect fluoride's effectiveness in protecting teeth?

https://fluorideresearch.org/484/files/FJ2015_v48_n4_p338-344_sfs.pdf

@SnipSnip Thanks. That was a fun read. I got from it that higher temperatures weakens concentrations of fluoride.

Do you always drink hot water?

@kritiper No; but I brush and rinse my teeth with hot tap water.

@RedDeerGuy1 That shouldn’t be detrimental to the overall effectiveness of fluoride.

@RedDeerGuy1 my take on the article is that increasing temperature increase the toxicity of fluoride to aquatic life. Which probably makes it more effective at preventing cavities.

I guess the first question would be How Soluble is NaF? This table tells us that as temperature goes up from freezing to boiling, NaF becomes more soluble. That means more of the chemical will go into solution. But if you look between 20C and 50C (roughly 68F to 120F) the solubility goes up about 15%. But what that could mean is that rinsing with hot water will remove the existing NaF from the toothpaste (or off the tooth) and put it into solution.

The article about the change of toxicity is interesting, but the testing involved long periods of time…24 hours was the shortest. If you are holding the water/NaF solution in your mouth for a whole day, it might have a great impact. But for the 30 seconds it is in your mouth, the water temp will not do a damned thing as far as increasing the toxicity significantly.

But the other part of the equation that needs to be looked at is how the NaF is actually protecting teeth. Can we agree that it is helping to kill harmful bacteria? The Fluoride is a great poison and will kill bacteria. The problem with fluorine is that it is extremely reactive.
It wants to attach to anything and everything. It also has an affinity for bone (or tooth in this case) because it wants to attach to the cells. The toothpaste uses sodium or tin to combine with the fluorine to make sodium fluoride or stannous fluoride…a more stable form of the element desired. These chemicals dissociate in water, releasing the fluorine atoms. When the fluorine hits the teeth, it wants to react with the bone cells. This happens fairly quickly and temperature may play a small role. The time involved in you brushing your teeth and rinsing with hot water is so short that it won’t make much difference.