Kathylee, a thourough dental exam is the only way to find out what a dentist can do for you, but for at home use, can you use some of the natural toothpastes like Tom's of Maine? Barring that, baking soda and water make a good paste that cleans well. Flossing is important, and maintaining calcium intake, but you should probably work with your doctor on that one, to see what an optimal dose would be for you.
Many candies are sweetened with sorbitol or maltilol, which are natural alcohol sugars, and there are a few with xylitol, which is birch sugar, and very good for the teeth. I do know of some diabetics and kidney failure patients who suck on pebbles, beads or buttons to stimulate saliva.