Abstract
The aim of this study was to investigate the influence of post-core methods and the remaining radicular tooth structure on the fracture resistance of pulpless teeth. Two types of remaining radicular tooth structure were tested: one group had sufficient radicular tooth structure, and the second had thinwalled-flared canals. The prepared post holes were restored with one of five different post-core methods: the metal post and cores cemented with zinc-phosphate cement; the metal post and cores cemented with Super-Bond C & B; C-POST and composite resin core; AD POST II and composite resin core, and composite resin only. Each group was tested until the root fractured with a slowly increasing force at 90 degrees to the long axis.
The results were as follows:
1. The use of a metal post and cores resulted in higher fracture resistance than those recorded for teeth restored with composite resin.
2. Fracture resistance of teeth restored with a metal post and cores decreased with decreasing radicular tooth structure; nevertheless, there was no significant difference.
3. A composite resin post and cores could be used for the restoration of thin-walled-flared canals.
4. Fractures were detected at the core-dentin interface in all specimens; therefore, core-dentin interfaces must be strengthened.
