Influence of Glass Fiber Post Design and Luting Cements on Ease of Post Removal and Fracture Strength of Endodontically Retreated Teeth

Abstract

A BSTRACT Aims and Objectives: The aim of this study was to evaluate the time needed to remove two types of glass fiber posts cemented with two different cements and removed with two different techniques and to evaluate the fracture strength of teeth after post removal. Materials and Methods: Root canal treatment was completed in 80 extracted single-rooted premolars and the teeth were decoronated. Following canal preparation, the roots were coated with polysiloxane impression material and embedded in acrylic resin cubes. The specimens were randomly divided into eight experimental groups ( n = 10) based on the type of fiber post inserted: Reforpost (R) or Contec Blanco (C); luting cement: Multilink-N/self-etch (M) or G-Cem/self-adhesive (G); technique of removal: Peeso reamer (P); or ultrasonic (U). The posts were removed with respective technique under magnification and the time (in seconds) of post removal was determined. Following post removal, the fracture strength of the specimens was determined using a universal testing machine. The mode of failure was also determined. Data were analyzed by three-way analysis of variance (ANOVA), one-way ANOVA, Tukey’s post hoc test, t test, and correlation. Chi-square analysis was performed to compare the failure mode. Statistical significance was set at P < 0.05. Results: The post and cement types had an influence in post removal time ( P < 0.05). There was no role of post or cement types on the fracture strength of teeth after post removal with either technique ( P > 0.05). A weak negative correlation was found between the post removal time and fracture resistance for both Peeso reamer ( r = –0.373) and ultrasonic ( r = –0.177) techniques. Both techniques of post removal produced a majority of favorable failures ( P > 0.05). Conclusion: The type of post and luting cement plays a significant role in ease of post removal by Peeso reamer or ultrasonic technique. Post-removal technique had no effect on the fracture strength of teeth. Parallel serrated fiber post luted with self-etch resin cements was difficult to remove as compared with parallel smooth surface post luted with self-etch or self-adhesive resin cement.