My mother has had dentures as long as I can remember. I don't think I inherited good teeth. I have spent much more on dental care than medical care. That is for sure. With most of my molars now capped and in good shape, I can only hope I'll never end up with dentures.
I cracked/broke off pieces of a couple of (back) teeth long BEFORE I went vegan. One I never had treated for years and it never bothered me. They now can fill those areas in with bonding that is the same color as your tooth and you can't even see it.
I can't tell you what to do but I do know people do have pieces of teeth break off even if they are not vegan. I had a lot of the old silver fillings in my mouth which caused some small pieces of tooth to fall off around them. All those silver fillings are now removed. I do plan to get a calcium level and B12 level in the not too distant future.