[Effect of thermo-mechanical load cycling on the fracture strength of upper central incisor restored with three different types of glass-fiber posts]

ABSTRACT

The aim of this study was to evaluate the fracture strength of restored teeth with three different types of E glass-fiber posts after thermo-mechanical loading. Sixty extracted upper central incisor human teeth, with similar size, were selected and divided into three groups [n=20]. Endodontic treatment was done in all groups and crowns were sectioned from 2 mm above CEJ. Then one type of posts in each group [Anthogyr, Svensk, Hetco] cemented using Panavia cement and the crowns were restored with a composite. The specimens in each group were thermocycled for 6000 cycles [5-55°C] and subjected to 1200000 cycles of mechanical loadiong in an artificial mouth machine. Then the fracture strength was measured and data were analyzed using ANOVA and T-student test [alpha=0.05]. The mean fracture strengths in Hetco group before and after thermomechnical loading were 581.098 +/- 192.742 N and 564.74 +/- 213.59 N, in Anthogyr group were 664.358 +/- 135.878 N and 629.12 +/- 390.3 N and, in Svensk group were 780.258 +/- 379.133 N and 779.84 +/- 282.59 N, respectively. There was no significant difference between groups and also there was no significant difference in each group before and after thermo-mechanical loading [P>0.05]. Restored teeth with Hetco fiber glass post were similar in terms of the fracture strength with that of two other posts after thermo-mechnical loading