A prosthodontic device applicable to the remainder of a root of a tooth that has received complete endodontic therapy includes a post and a core integrally formed with one end of the post. The post has a post body and a connection unit formed on the surface of the post body. The core has a head to sit on the top end of the remainder of the root of the tooth and at least one shoulder formed on the head. The largest diameter of the core is larger than the largest diameter of the post body of the post. The prosthodontic device enables rapid completion of tooth preservation and restoration after endodontic therapy.