I think I halted the progression of a cavity. I had a soft spot a front lower tooth on the outside. The dentist noted the soft spot and said that that might turn into a cavity. The soft spot has since turned black and hard. The dentist said that sometimes the decay turns black when it stops. That was two years ago.
I supplemented with Thorne Research K2, a drop a day most days of the week for over two years. I'm on my third bottle of Thorne K2. Slight Magnesium (glycinate) supplementation.. ie 200mg/day most days of the week. I tried the butter oil, but I stopped because more than 4mL or so gives me acne. I tried cod liver oil, but stopped when I bought a bottle of the unflavored kind. I don't do bone broth. I don't eat liver, but I do eat a lot of heart and tongue.
I wonder how I will do when I go to the dentist this time because I've been more lackadaisical with the K2 and magnesium as well as eating more fruit. I'm lackadaisical about brushing. I'll do it a couple of times a week.
Edit: Oh, yeah, I was pretty good about supplementing vitamin D, too. ~4000/day