| dc.description.abstract | Statement of Problem. Previous studies have not examined cantilever length nor cross-sectional dimension of connector sites of poly-ether-ketone-ketone (PEKK) frameworks.
Purpose. The purpose of this in vitro study was to investigate the effect of cantilever length and cross-sectional dimension of connectors on the fracture resistance of poly-ether-ketone-ketone (PEKK) frameworks.
Material and Methods. Sixty frameworks were digitally designed and milled from PEKK blanks. All specimens were prepared in 6 different groups (n=10); group 4.07 (3 mm width x 4 mm height and 7 mm cantilever), group 4.10 (3 mm width x 4 mm height and 10 mm cantilever), group 4.17 (3 mm width x 4 mm height and 17 mm cantilever), group 5.07 (3 mm width x 5 mm height x 7 mm cantilever), group 5.10 (3 mm width x 5 mm height and 10 mm cantilever), and group 5.17 (3mm width x 5 mm height and 17 mm cantilever). The specimens were subjected to a static load until catastrophic fracture occurred, directed by a sudden load drop indicating maximum load-to-fracture values. Statistical analysis was performed by using two-way analysis of variance (ANOVA) followed by the Sidak post hoc test (α=.05).
Results. The two-way ANOVA revealed that the interaction between connector cross-sectional area and cantilever length on load-to-fracture values was found statistically significant (P<.001). The post hoc Sidak test revealed that there were no statistically significant differences were found between Group 4.07 and Group 5.10 (P=.076).
Conclusion. Load-to-fracture values were significantly decreased by increased cantilever lengths and decreased connector sizes. The highest load-to-fracture value was 409.91 ± 3 N was found in Group 5.07. Groups with 17 mm cantilevers (Groups 4.17 and 5.17) could not significantly increase by an increase in connector size as much as small cantilever length groups (Groups 4.07, 5.07, and 4.10).
Clinical Implication: Connector size and cantilever lengths of PEKK dental fixed prostheses should be designed with caution. | en |
