Endodontics is a branch of dentistry that deals with the problems that have advanced to the region where the nerve and vascular packs, which provide the vitality of the tooth, which we call dental pulp, is located. The tooth pulp may be damaged or lost its vitality for a reason such as cavities or trauma. In this case, these teeth should be treated with the correct diagnosis and planning to eliminate the infection and prevent its spread. If the tooth pulp has undergone irreversible damage, this tissue, most of which is located in the root part of the tooth, which is not visible in the mouth, is properly removed, the tooth channels are shaped with special devices, cleaned with disinfectant solutions and filled with a tissue-friendly material. Root canal treatment, which has been a feared treatment method that lasted through the sessions in the past, has become a very comfortable and short-term treatment today with the development of technology. Since the canal system of the tooth is a complex structure, treatments that are not ideal can result in failure and cause tooth loss. For this reason, these treatments should be performed by specialist physicians.