Abstract
Purpose: The aim of this study was to determine the optimal disposition of fiber posts in composite resin core materials for endodontically treated teeth.
Materials and Methods: Composite resin core material was filled in a glass tube that was 3 mm in caliber and 24 mm in length and one or four fiber posts were additionally inserted with the planned disposition into the core materials, followed by light irradiation. The composite resin core complex with fiber posts was removed from the glass tube, trimmed to a specimen of 20 mm in length and embedded at a depth of 10 mm in a ring filled with self-curing resin material. The initial and maximal failure strength, failure modes and the displacement of the loading point after static and cyclic loading were measured.
Results: The composite resin core complex with fiber posts of 1.0 mm and 1.6 mm in diameter, which were placed at the tensile side of the complex, showed a significantly higher value in the initial failure strength than the composite resin cylinder with no fiber post. The complex with a fiber post of 1.6 mm in diameter, which was placed at the tensile side, indicated signifi cantly the highest value in the maximal failure strength among all complexes. Both the complex with a 1.6 mm fiber post and the complex with four thinner fiber posts displayed the smallest displacement of the loading point after cyclic loading.
Conclusion: Disposition of fiber post in the composite resin core materials was a significant factor for the initial and maximal failure strength and also displacement of the loading point after cyclic loading. Especially, it is recommended to place the fiber posts at the tensile side of the complex.
