If a tooth has become significantly decayed and rotten the nerve inside will become very sick or even infected. This usually results in a lot of strong, intense and throbbing pain to hot, cold and pressure. At this stage it’s too late to do a filling and the only option to fix the tooth is a root canal treatment. The treatment usually requires 3-4 visits in which the sick or infected nerve is removed from the canals inside the tooth, then medicine is placed to get rid of the pain and kill bacteria, and finally a filling is placed inside the canals to seal the space and prevent bacteria getting back in. This is time consuming, highly technique sensitive and high in cost. A root canal treatment can be avoided by having your teeth checked regularly and fixed early.