Crown, crown-root or root fractures can be seen in endodontically treated teeth. This occurs as a result of removing too much material from the tooth structure during preparation, applying too much force while filling, or inadequate planning of the coronal restoration.In such cases, if excessive crown destruction has occurred and the fracture line extends below the gingiva, a restoration with periodontal surgical support should be considered. However, the treatment with glass fiber reinforced post and zirconium crown applied together with periodontal surgical support in such teeth is a satisfactory treatment method in terms of both aesthetics and function. In this case report; In this article, the restoration and follow-up of the lost function and aesthetics of posterior teeth due to a complicated crown fracture extending to the underside of the gingiva with fiber post and zirconia supported all-ceramic restoration is explained through a clinical case.