xylitol vrs sorbitol

for as long as i can remeber anyone writing about it, i have been touting the benefits of xylitol. there have been studies published around the world, from a variety of entities (such as the university of michigan) telling how regular exposure to xylitol can greatly diminish the process of getting cavities. xyltiol works in many different ways, from actually killing the bacteria to inhibiting the bacteria that cause cavities from attaching to the teeth. no bacteria no cavities.
however, xylitol is fairly expensive compared to sugar or sorbitol so it is not used as much as sorbitol.
i recently read a study that said if you get more than 3 exposures a day to sorbitol you can expect the acid/base balance of your mouth to shift to the acid side. what this really means is that wyile sorbitol has no calories, if used more than 3 times a day it no longer is cavity free, but cavity reducing.
so, the best gum to chew needs to have xylitol listed as it's first ingredient, anywhere else and there is not enought xylitol. also, if xylitol is not the first ingredient, then you can bet it will be sorbitol. the few gums available over the counter that have xylitol as it's first ingredient are carefree koolerz , armand hammer sugarless gum ( i have heard of it but never have seen it in a store) and altoids sugarless gum (not their mints, they are sweetened with sorbitol) you can also do a search on the internet and find a dozen other brands of gums to find. my suggestion, find the gum and use is 3-4 times a day for at least 5 minutes. this will greatly enhance the possibility that you will need less dentistry done over your lifetime, and isn't that what everyone wants?