Let me start by saying I am not bulimic or a methampetamine user. Recently, while chewing a piece of popcorn, one of my teeth broke off (1/2 of the actual tooth) in my mouth. It alarmed me however I had a filling in the tooth and the filling remained intact. Later that same day, while chewing a piece of toast, another tooth broke off, again more than half of the tooth is now gone. I recently started injections for acute back pain and am on my second injection. I am now wondering if this is a possible side effect since my teeth are otherwise in excellent shape. I visit the dentist twice a year and have not had cavities in ages. I have all my real teeth and take great care of them. I am devastated and will be going to the dentist on Tuesday to get temp crowns or whatever they feel needs to be done. What could possibly cause dramatic teeth cracking without eating hard foods. I am desperate as I am limiting myself to liquid foods to avoid losing any others!