Evaluation of linear-elastic fracture toughness of the teeth restored with different post and core systems

The purpose of this in vitro study was to investigate the linear-elastic fracture toughness of endodontically treated teeth after restoration with prefabricated post systems against root restored with metal cast post-core. Thirty two maxillary canines with similar anatomic characteristic were sectioned to obtain the same length for all specimens. Group I consisted of 8 roots restored with FibreKor system; Group II consisted of 8 roots restored with C-Post system; Group III consisted of 8 roots restored with metal cast post-core (the diameter was similar FibreKor system); and Group IV consisted of 8 roots restored with metal cast post-core (the diameter was similar C-Post system). Specimens were cemented with dual-cure bonding agent (Dual-Cement and Unibond). These specimens were then mounted in acrylic blocks and tested in a universal testing machine (Kratos). Each sample was angled at 135° to the long axis of the root. A constantly increasing force was applied until the root fracture. Means (kilogram force, kgf) and standard deviations for four groups were found to be: Group I, 31.01 (2.08); Group II, 41.32 (3.44); Group III, 49.17 (2.09); Group IV, 47.65 (2.94). The present research indicated that root restored with metal post was statistically significant (p<0.05), more resistant to fracture over root restored with non metal post.