Effect of fiber posts with different emerging diameters on the fracture strength of restored crownless teeth

The relatively low elastic modulus of fiber posts reduces the risk of root fracture, but it also decreases composite core stabilization. To compensate for the lack of rigidity, larger post sizes can be necessary when restoring crownless teeth that have significant internal destruction of the root canal. This study evaluated the effectiveness of fiber posts with different emerging diameters and shapes on composite core stabilization as measured by fracture strength testing. Fracture strengths ranged from 262.6 ± 81 N to 422.8 ± 56 N. A one-way ANOVA test showed that fracture strength was affected by type of post (p<0.0001); single-tapered posts were weaker than double-tapered posts. Pearson's linear correlation test showed that the fracture strength results appear to have a direct correlation to the emerging diameter of the post (p<0.0001; r(2)=0.6191). The emerging diameter of fiber posts is important to stabilize the core. When restoring crownless teeth, it is advisable to use fiber posts with large emerging diameters; no additional preparation of the internal root dentin is necessary to enlarge the post diameter.