Saltpeter really? WTF

[budcud]

So my teeth arn't in the best shape and so i'm using a toothpaste for sensitive teeth. Wondering what the ingredient is that is helping me out I read, Potasium nitrate 5%, aka Saltpeter. I have enough problems maintaining an erection w/o some chemical I dont need sneaking into my system. People I've taked to say it nothing but a old wife's tell and not to be concerned. I take vitamins with other metals and compounds that are supposed to help me and I see a difference.
Are there any Dr's or AD's that can shed some light on this one???

[i'va biggen]

Think they use to use it to make gunpowder so when you shoot a load it might blow her ass off.