Comparison of the push-out bond strength of different prefabricated fiber post systems: An in vitro study

Abstract

Introduction: The aim of the current study was to evaluate the effects of post type and hydrothermal aging on the push-out bond strength of four different fiber post systems. Materials and Methods: Eighty extracted human upper central incisors were treated with root canal treatment and divided into four different groups according to the treated post system (UniCore post [group U] [n = 20], Reforpost fiber [group R] [n = 20], Voco Rebilda post GT [group V] [n = 20], and EverStick post [group E] [n = 20]). The posts of teeth in all groups were divided into three parts from coronal, middle, and apical aspects. Half of the samples in all groups were subjected to hydrothermal aging (10,000 cycles). All subjects were applied to the crosshead speed push-out bond strength test at a 1-mm/min rate until being fractured. Fracture types were determined with a stereomicroscope. Data were analyzed by Kruskal–Wallis and Chi-square tests statistically. Results: Bond strength values of EverStick post were significantly lower compared to the other groups (P < 0.01). In the presence/absence of hydrothermal aging, push-out bond strength in the coronal and middle regions was significantly higher compared to the apical region in all groups (P < 0.01). Bond strength values decreased in all groups following hydrothermal aging (P < 0.01). Conclusions: Push-out bond strength may be affected more negatively from coronal and middle of the tooth compared to its apical part. Hydrothermal aging may worsen the bond strength. The use of Reforpost fiber, VocoRebilda post GT, and UniCore posts may provide better bond strength compared to EverStick post.