In the large cavity of necrose teeth, an adequate final restoration greatly influences case prognosis. The addition of intracanal retention and suitable cores will increase treatment success. Intracanal retention has several types of material and shape configurations. The radix anchor is a type of metal post with a parallel and threaded configuration and has a bristled head. This configuration will increase retention in both the intracanal and core sections, thereby increasing the final restoration's retention strength. A 42-year-old female patient presented with a left upper back tooth broken and swollen for three years. The objective examination of tooth 24 showed that a minimum residual tooth of less than a third of incisal height with percussion, palpation, and vitality examinations indicated a negative result. Radiographic examination showed a straight root canal with thickening of the periodontal ligament at the apical third. In this case, conventional root canal treatment was performed with the crown down preparation and single-cone method root canal filling and continued with the final restoration. Metal radix anchor post was placed in the root canal and continued with composite resin core attached to the flared head of the radix anchor. The composite resin core preparation was carried out and continued with dental impression with an elastomer material for the fabrication of a porcelain fused metal jacket crown. One month follow-up after the final restoration showed no complaints on subjective or objective examinations. Radiographic examination showed that the periodontal ligament thickening has diminished.