I haven't had root canals, but I had several tooth infections for over ten years, and probably almost 20 years. Putting a cashew on a tooth ache often used to help. Then last year oil pulling worked for a few months. Then in August when oil pulling stopped working, I got Miracle-Mineral-Supplement and it worked within a week or so. The tenderness of my gums faded away. My neck and headaches largely subsided. Even a growth or tumor on my gum for over 5 years is now almost gone. After using Miracle-Mineral-Supplement twice a day for a month or so, I started using it only when I start to feel a little gum tenderness, or a headache, which is once every few weeks, so far. Since bacteria are constantly in the mouth, I think they have opportunity to re-infect formerly infected areas, at least till those areas heal more completely to close up all of the voids. I've been getting dry mouth at night and dry nasal passages, so I'm trying to find a solution for that. Someone said to drink more water, so I started doing that yesterday.