A personal anecdote - but one approved and confirmed as general dentist wisdom by a friend of mine who is a dentist.
I always had problems with cavities, since my youth there never was a dentist visit where they didn't drill. About 7 years ago I drastically cut back on sugar, not because of teeth but because of other issues (now resolved).
I used to be a typical German: I could not live without a bakery. I ate loads of bread, pasta, pizza (but actually good one) - and between meals not infrequently cookies or a piece of cake. I also ate quite a lot of chocolate and other sweets, always desert. LOTS and lots of fruit (self-made fruit salad!)
Before I give you the wrong idea that I may have to mention I never had a weight issue, I was very active too..Not that you think what I'm saying only applies to obese people and so what I'm writing does not apply to others. I could easily - and I mean easily - run a half marathon (never tried more than that), just for fun.
Anyway, my health issues forced me to experiment. To cut the story short and leave out all the experiments and everything in between, without consulting any book or "nutritionist", only learning to read and listen to what my own body was telling me, I ended up eating very few "carbs" (not the chemical meaning of the word but the kinds of foods). I almost never buy anything from the bakery, except for (very good!) white bread, which lasts two weeks or so (or even more). NO chocolate, no cake, no cookies. Very few fruits, and even less of the sweet kinds of fruits. Almost never bread, almost never pasta, almost never potatoes. NO SUGAR. Again, no extremes: I'm sure one or the other salad dressing I got when I didn't eat at home had sugar. I would not even mind eating a piece of cake now and then - if only I had any appetite for that stuff. I never do, not any more.
I don't have to force myself to any of it, it comes naturally now!
On the other hand, I eat a lot less meat than in the past too. Again not because of some "nutrition advice" that I follow, I really can't!
But I could never eat something as extreme as an Atkins diet. I _do_ need carbs (that's why the white bread), just very little. I could also never go without meat, go full vegetarian. No extremes (unless "No sweets" is something you consider extreme).
What I eat a lot more of: Fat and vegetables. Fat in the form of olive oil, nuts (lots! - what is the English word for "Nussmus"??? Darn!), cream. Quite abit of dairy, but zero milk, all in the form of cheese and other kinds of milk that went through bacterial processing.
MY TEETH:
I have suddenly had ZERO problems with my teeth for years! A complete change! And I don't even need to brush my teeth. Okay, for breath :-) Not a single cavity anywhere. My dentist friend just said "Of course, if you leave out the sugar that's to be expected."
