On topical application it repairs your teeth by helping to harden and re-crystalize the calcium structures your teeth are made of. When ingested It is a neurotoxin, cuts IQ like leaded gas did which leads to more crime and useless violence, massively raises the rate of bone cancer in pubescent and pre-pubescent boys, it doesn't help your teeth at all as advertised. I don't know dick about pineal gland calcification, that wasn't documented when I researched it over a decade ago, there was loose documentation, about it being used as a mass sedative at various concentration camps in germany during the war, though I suspect much of that was faked or manipulated but I have heard rumors that it can make you a bit apathetic or harmless, which could fit with the pineal gland stuff. Japan banned it IIRC and have a nontoxic toothpaste alternative that seems to work well.