Please google "fluoride toxicity" to easily inform yourself! This is just one quote from Wikipedia, and it is very shocking to read this.
The NRC report stated that "many of the untoward effects of fluoride are due to the formation of AlFx [aluminum fluoride] complexes".[17]:219 This topic has been identified previously as cause for concern.[22] The NRC noted that rats administered fluoride had twice as much aluminum in their brains.[17]:212 When water (1 ppm fluoride) is boiled in aluminum cookware more aluminum is leached and more aluminum fluoride complexes are formed. However, an epidemiological study found that a high-fluoride area had one-fifth the Alzheimer's that a low-fluoride area had,[23] and a 2002 study found that fluoride increased the urinary excretion of aluminum.[24]