What kind of toothpaste do you use for your toddler? Mine still swallows, so definitely no fluoride. I've heard of two that are great for healing teeth, or something, but I can't remember the names of them. Currently, we're using Tom's glycerin paste, strawberry flavor, but I heard that glycerin paste is very sticky on the teeth, and can make tooth problems worse.
FYI, DS has very bad decay on all his top teeth, despite very little sugar (in fact, it started before he'd ever really had any sugar) in the diet, and brushing regularly. The dentists keep telling me it's because I'm not brushing enough, and ignore the fact that we DO brush. I think they just don't believe me.