Post it? Reconstruction of the endodontically treated tooth.

This thesis is addressing the reconstruction of the structurally compromised endodontically treated tooth. This reconstruction is challenging every dental practitioner. The general objectives of present thesis were to address the issue of the requirement of a (metal) post, to investigate the influence of a covering crown, and to investigate the added value of fiber reinforced composites. The start is a structured literature review on in vitro failure loads and failure modes. It was concluded that custom-cast posts show higher failure loads compared to prefabricated fiber-reinforced composite (FRC) posts of reconstructed teeth. However, the use of prefabricated FRC post systems results in significantly more frequently favorable failures than prefabricated metal and custom-cast post systems. The core of the thesis describes three laboratory load tests and two long-term clinical follow-up studies. From the laboratory studies it was concluded that reconstructed premolars (with and without crowns) with various post-and-cores behave similar. A fiber fabric within a composite core-crown reconstruction did not improve the fracture resistance, however, the failure mode was less destructive. The clinical studies revealed no difference in survival between crowned teeth with and without different metal posts, nor between composite core-crown reconstructed endodontically treated teeth with or without posts. On the basis of the studies in this thesis it is concluded that: metal posts are not necessarily required to improve fracture resistance, nor to increase the longevity of reconstructed endodontically treated teeth. Fiber-reinforced materials can be beneficial in the failure mode of endodontically treated teeth.In this respect, beneficial means that less frequently irreparable failures occur. Postponement of a covering crown, with a direct resin composite core-crown reconstruction, must be considered in endodontically treated teeth in specific cases, for example when solutions need longer evaluation periods