IADR Abstract Archives
Influence of the stalk on the repeatability and fracture type of shear bond strength assay
Objectives: To evaluate the accuracy of the shear bond strength test using two forms of loading stalk (straight and curved) and 2 sample diameters (2,38 mm and 5 mm) and also to analyze and evaluate if there is a pattern established on the type of fracture depending on the shape of the load stem, the diameter of the sample and the position of the sample in the machine.
Methods: 32 monolithic samples of Acronitrile Butadiene Styrene (ABS) were used to minimize the factors that influence adhesion,so to evaluate the precision of the Zwick Pro Line Z005 machine involving less variables. Four groups were created and the samples were divided equally: 8 for straight stalk and 2,38mm, 8 for straight stalk and 5mm, 8 for straight stalk 2,38mm and 8 for 5mm curved stalk. The stereomicroscope Stereo Discovery V8 was used for fracture analysis.
Results: There were no statistically differences between the accuracy of the 4 groups. There were statistically significant differences when we compared the resistance to fracture using a straight or curved stalk. Regarding the type of fracture there was no dependence according to the diameter and the type of stalk.
Conclusions: The shape of the loading stalk and the diameter did not affect the accuracy of the shear bond strength test, but they did significantly affect the resistance. The shape of the loading stalk and the diameter could not be related to the types of fracture that were found.
Methods: 32 monolithic samples of Acronitrile Butadiene Styrene (ABS) were used to minimize the factors that influence adhesion,so to evaluate the precision of the Zwick Pro Line Z005 machine involving less variables. Four groups were created and the samples were divided equally: 8 for straight stalk and 2,38mm, 8 for straight stalk and 5mm, 8 for straight stalk 2,38mm and 8 for 5mm curved stalk. The stereomicroscope Stereo Discovery V8 was used for fracture analysis.
Results: There were no statistically differences between the accuracy of the 4 groups. There were statistically significant differences when we compared the resistance to fracture using a straight or curved stalk. Regarding the type of fracture there was no dependence according to the diameter and the type of stalk.
Conclusions: The shape of the loading stalk and the diameter did not affect the accuracy of the shear bond strength test, but they did significantly affect the resistance. The shape of the loading stalk and the diameter could not be related to the types of fracture that were found.