I've been in touch with Dr. Manhart, who runs the calcium therapy site, for some time now. I mentioned OP to him once and he was dubious about it. Like most of us, he's not right about everything. :) I do use his products and they're helpful. He says he's saved teeth that were so loose they had to be held in the mouth while applying the calcium treatment! Anyway, take what you can use from him and leave the rest.