Endodontic therapy, which includes spreading, cleaning, disinfection, and filling root canals, while eliminating the hard dental tissue affected by caries, weakens the tooth's structure. The aim of post-endodontic therapy is adequate compensation for hard dental tissues in order to reduce the risk of marginal leakage and fractures, thereby preserving the tooth. When deciding on a therapy plan, it is necessary to make a correct diagnosis which includes taking an anamnesis, intra- and extraoral examination, and evaluation of the periapical X-ray. Depending on the filling quality, it is sometimes necessary to make the revision of the filling before postendodontic therapy. Smaller crown defects are successfully compensated by composite or glass ionomer materials, while indirect restorations and, if necessary, intracanal restorations are indicated for bigger dental tissue losses. Inlays, onlays and overlays are made outside the patient's mouth, and differ from each other by the surfaces and number of cusps they cover. They are made out of ceramic and composite materials. There are two large groups of post and core: individual and confectionary. The most commonly used intracanal restorations are posts reinforced by glass fibers because of their of good mechanical properties similar to dentine, but also because they ensure the retention of the future restoration, crown or bridge. In case of the large crown defects it is indicated to restore a tooth with the crown. The main objectives of post-endodontic therapy and adequate endodontic treatment are to prevent the penetration of microorganisms, to reconstruct lost hard dental tissues and to meet the patient's aesthetic requirements. The success of therapy is influenced by proper diagnosis, respect for all steps during the therapy, collaboration with the patient and his or her care of oral hygiene.