Issues‎ > ‎Vol 7, issue 1‎ > ‎


Failure Modes of New Fiber Post Systems Using Stereomicroscope: An in Vitro Study

Hani M. Mouafaq* , Shakhawan K. Kadir** 

Department of Conservative Dentistry, M.Sc. Students, College of Dentistry, Hawler Medical University, Erbil, Iraq.
** Department of Conservative Dentistry, College of Dentistry, Hawler Medical University, Erbil, Iraq.

Submitted: 12/08/2019; Accepted: 25/02/2020; Published 01/06/2020



Objective: Failure of the glass posts is a major and the main concern of practical dentistry. This study conducted to evaluate the mode of failure among prefabricated bundle fiber posts, prefabricated taper fiber posts, and short fiber-reinforced composite as a post and luting material using a stereomicroscope.       

Methods: Thirty mandibular premolars were divided into three groups (n=10). Group 1: prefabricated taper fiber post cemented with a resin core, group 2: prefabricated bundle fiber post cemented with a resin core and group 3: short fiber-reinforced composite used instead of post and cement. Each root specimen cut into three slices of 2 mm thickness from the cervical, middle, and apical parts of the posts. Push-out tests were performed using a universal testing machine at three sites in each root at a crosshead speed of 0.5 mm/min. Then, the specimens evaluated under stereomicroscope 40X to classify the failure mode.

Results: Sixty two specimens failed adhesively between dentin and cement in all groups, adhesive failure between the post and cement was in the second group, prefabricated taper fiber post (GC fiber post) followed by prefabricated bundle fiber posts (Rebilda GT) (17 sections), and the mixed failure was second for prefabricated bundle fiber posts (Rebilda GT) and third for prefabricated taper fiber post (GC fiber post) (11sections). 

Conclusions: Adhesive failure between cement and dentin is dominant in all post systems in three sites of the roots (cervical, middle, and apical). The second most frequent failure is adhesive between post and cement in all regions in post systems.


Keywords: Fiber post; Bundle post, Short fiber-reinforced composite, Failure modes.                                                                                                                                                                                             Full Article - PDF                                                                                                                                                                                                                                   


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