Water fluoridation controversy - Prosper Learning

[prosperlearning]

Hi, I'm Paul and I work for Prosper Learning and I would want to know if you have any info about sodium hexafluosilicate that is added to drinking water It is known to cause some mental disease if used on long term.
Water fluoridation has provoked controversy though opponents of fluoridation have not assembled as a majority in the scientific community. Whether for health concerns or concerns of consent or because their people are receiving fluoride through other means, some governments have ceased or decided not to start fluoridating their water.
Anyway, it seems that fluoridation is still used in 60% of US territories.
Best regards,
Paul - Prosper Learning