Root canal treatment is carried out when the innermost part of the tooth becomes badly decayed or infected. If left untreated, could result in the lost of the tooth. The first step of root canal is to ensure the tooth is cleaned and decay free. The inside of the tooth or the canals are then irrigated and cleaned. As the canals of the tooth are very small, the dentist will then widen the canals and finally place the root canal filling all the way to the tip of the root to prevent re-infection. A cap or a crown is recommended after root canal treatment to protect the structure of the tooth.