Well, the ideas weren't earth-shattering, but they could have been a solution for someone else (I figured out what I think is our problem a bit later). The first mentioned phosphorus, as in possible deficiency (she specifically said it was unlikely to be a calcium excess), but we eat meat, and animal products are the biggest sources of phosphorus in the US diet (typically, I mean), so that seemed unlikely. The next didn't have ideas about root cause, but suggested a pointier toothbrush and a different angle (basic, but I hadn't considered it) because the tartar is on my son's bottom teeth which are crowded and form a V back into his mouth (hello, Weston Price ideas on dental structure and maternal health--it really fits our situation, for many reasons). I was already brushing and flossing 2x/day, had been for months, because I was worried about that area of his teeth, since it was so crowded (so they couldn't ding me on that

).
Personally, I think _I_ induced the tartar by over-supplementing with cod liver oil and not ensuring a good source of vitK2 (Price's Activator X). It started a few months after I started the CLO and seemed to stop progressing when I stopped the CLO (I stopped on a hunch). It fit together with the ideas in the Chris Masterjohn article on vitamin K2 (got it from the vitamin k yahoo group files, if you're interested and don't already have a copy). Vitamin K is really important to calcium regulation and I think I messed with that (I gave more than the WAPF guidelines because I had other info that suggested a vitA deficiency for my son--I was giving 10-15k IU/day). I'm supplementing with Thorne K2 now, and slowly adding back in the CLO, but I plan to get back to that range within a few months.
I love the Curing Cavities with Nutrition thread. Since we can't have any dairy, it's a bit trickier for us (one of several reasons I'm using supplements) but I think Price has a lot of the fundamentals of good nutrition in his book (Nutrition and Physical Degeneration was worth the price).
Oh, I've read good things about MI Paste (I think that's the name), from folks who've been successful at healing cavities. It's milk-based, so we haven't done it, but an idea.
Good luck to you as well!