Well I think you must realize by the other post, flouride is very bad. My best friends brother was given extra flouride starting at about 11 by his well meaning Dad, and now has very brown spots all over his teeth.
I use Xylitol toothpaste by Spry. Be careful to read all the labels because even Tom's has toothpaste with flouride.
Glycerin is one of the things to stay away from. Appartently it takes 27 brushings to get one coat off your teeth. Unfortunately the Spry toothpaste has glycerin, so as soon as we are finished with this tube, we will only use the Microbrite Antioxidant Tooth powder.
Alas, my family is very upset about giving up the toothpaste. I will have to keep some of the Spry around for their occassional use.