I am 30, I have 2 cavities, I just went in for a cleaning and have a clean bill of health. My teeth have always been sensitive to gummy type snacks, so I just don't eat them. Increasingly so, my teeth are more sensitive after this last pregnancy. In so much that a JP gummy will drop me on the floor in pain. Dentist's verdict is "some people just have sensitive teeth". Well, being the whole-body person, that's crap. So what is it? I have ALWAYS used glyserin toothpaste, Toms of Maine, but went on regular Crest Sensitive with Flouride for 1 month, and noticed no difference. We drink flouride free water, for the past 2 + years. Again, I have virtually no cavities, no concerns about enamal.
I am nursing still, just morning and night, an 11 mo. old. Perhaps my calcium instake is a little low and I probably could drink more water, better hydration. I had thrush last month and was on a virtually sugar free diet, and as little carbs as I could tolerate...that made no difference.
I'm to the point where I think I just need to try some sensodyne and forget it, but if I could find the cause (if there is something beyond "some people are just..." I would be a much happier camper. 30 is too young to have tooth sensitivity like this "forever".