The absence of fluoride initially causes severe dental sensitivity due to acidic foods, which is the concern here. If you have always been using fluoride toothp

The absence of fluoride initially causes severe dental sensitivity due to acidic foods, which is the concern here. If you have always been using fluoride toothpaste and drinking fluoride-containing tap water, you will not understand. Toothaches are indeed also caused by headaches, oral infections, and sinus infections/allergies/irritation. Sometimes it's sinus related and sometimes it isn't. These have nothing to do with tooth sensitivity.