In my first post there is a link that goes to a discussion about this.
Re Ramiel Nagel's work, it is really up to you to decide whether you want to try his approach. I have adapted a number of his recommendations and I feel it's helping. Re the fruit question, I feel it is best to eat fruits along with leafy greens, this helps balance the fructose. I make green smoothies using fruit. If you Google "green smoothies" you'll find a lot of info and recipes. Also, berries are low-sugar and should be no problem. I love raspberries myself.
You ask if Nagel's approach would help teeth that have had dental work. Yes, of course, he'd have a very small readership otherwise!
I see from your other questions that you are quite skeptical about oil pulling. But you are here, so you must have an inkling that it could be helpful. I advise you to look around and take advantage of all the good info available. You might want to check out the recommended messages highlighted at the top of the forum page. There is also a search option.