Endodontics is the branch of dentistry that deals with the treatment of endodonto, which is the space inside of the tooth which contains the "pulp" which is a connective tissue having blood vessels, nerve endings and cells (dentinoblasti).

Endodontic therapy is used if a carious or traumatic lesion has resulted in an irreversible alteration to the pulp tissue, whenthe caries cavity has compromised the viability of the nerve and pulp. Tooth decay causes an inflammation of the nerve endings thus giving the patient a persistent pain known as pulpitis. If neglected and this becomes inflamed there can result a cross infection extending beyond the apex of the root, causing an injury called a granuloma ( or abscesses). At this stage the use of Endodontictherapy is necessary, as the only alternative is for the tooth to be extracted.