I always recommend xylitol. Is a nontoxic sugar substitute and with great oral benefits. It is used to sweeten coffee, tea, fruit drinks, cakes, etc. You can find it in powder, chewing gum, lollypops, mints and different candies and chocolates, even in toothpaste. Adults 4gr. daily, children 1gr. I constantly write about its benefits in my blog, twitter or Facebook. On this page you can find a variety of products.
And like always, I also recommend looking for it in amazon.