Comparison of the fracture resistance of endodontically treated teeth restored with two different types of quartz fiber posts (in vitro)

Very little is known about the fracture resistance of endodontically treated teeth restored with different design of esthetic post systems. The aim of this study was to compare the fracture resistance and failure mode of endodontically treated teeth restored with two different types of quartz fiber post. In this experimental، in-vitro study، twenty mandibular premolars with similar size were chosen and randomly divided into 2 groups (n=10). After cutting the crowns and endodontic therapy، the teeth were restored with a quartz fiber single taper light-posts in group A and quartz fiber D. T light-post in group B. All posts were cemented with a dual cure cement. Composite resin cores were built up using a pre-formed polyester matrix and every specimen was embedded in an acrylic resin block with a layer of elastic polyether Impergum surrounding the roots as PDL. Compressive load was applied at 135 degree angle to the long axis of the tooth at a crosshead speed of 1mm/min until fracture occurred. T-test was used to determine the significance of the failure load values between the two groups. There was no significant statistical difference in fracture resistance among two groups. The fracture load in groups A and B were 366. 7±102. 7 (N) and 382. 4 ±67. 3 (N) respectively. (P<0. 6) According to the findings of this study، two different designs of quartz fiber posts did not influence the fracture resistance of endodontically treated teeth.