Abstract
Purpose: A new “fiber post” material is expected to be effective against root fracture after restoring endodontically treated teeth. However, there have been very few studies on post-and-cores for abutment teeth of fixed bridges. The purpose of this study was to clarify the usefulness of the fiber posts and composite resin cores for abutment teeth of cantilever fixed bridges.
Materials and Methods: Three post-and-core methods (prefabricated metal post and composite resin cores, fiber posts and composite resin cores, and composite resin filling for post and cores), and three loading conditions (direct 45°, indirect 0°, indirect 45° to the tooth axis) were examined to determine the initial and maximum failure loads and mode of failure using 90 bovine teeth to simulate the human lower premolar.
Results: Indirect 0° and 45° loading were strong enough to reduce the failure load to one-quarter to one-half of direct 45° loading. The fiber posts and composite resin cores indicated almost the same initial and maximum failure loads as the prefabricated metal post and composite resin cores, and significantly higher maximum failure load than the composite resin filling for post and cores.
Conclusion: The fiber posts and composite resin cores indicated almost the same failure load as the prefabricated metal post and composite resin cores but the failure load reduced remarkably under the condition of abutment teeth of cantilever fixed bridges. Furthermore, the post and core method with fiber posts could not prevent root fracture of the abutment teeth.
