Comparison of glass fiber and biologic dentin posts in terms of fracture resistance and bonding strength

Post-cores are indicated for the restoration of endodontically treated and extensively damaged teeth to improve retention. The aim of this study was to compare bond strength and fracture resistance of different post systems. Ninety extracted human maxillary central, lateral and canine teeth were included. The teeth were divided into two main groups for fracture resistance and push-out test (n=45). Each group was subdivided to three subgroups (n=15) as follows; 1. Biological dentin post. 2. Glass fiber post. 3.Composite post. The posts were cemented with a self-adhesive resin cement. Each specimen was loaded by using universal testing machine at a cross head speed of 1 mm/min. parallel to the long axis of the tooth until fracture. Maximum force load for fracture was measured and the results were analyzed with 2-way Anova and Tukey HSD tests. For push-out test, 5 dentin slices (2 mm thickness) were obtained from each tooth and push-out bond strength was measured at five different levels using the universal testing machine. Data were analyzed using Tukey HSD and Kruskal Wallis tests. Mean fracture strength values of the test groups were 957 N, 1332 N and 1165 N, respectively. Difference between the glass fiber post group and the biological dentin post was statistically significant (p0.05). Mean bond strength values of the test groups were 8.57 MPa, 5.45 MPa and 4.49 MPa respectively. The highest bond strength was observed in the biological dentin post group (p<0.05). Biological dentin posts provide good esthetic and function. They are economic and biocompatible; however their fracture strength is not superior to the other post systems. Keywords: Biological dentin post, fracture resistant test, push-out test