Electro puls 3000

The studied cadaveric pieces were placed in a universal testing machine (Electro Puls 3000, Instron, Boulder, MA, USA) with the clamping jaws vertical. The base of the scapula was fixed to the clamp by a compression system using two plates with screw tips to ensure proper fixation. By means of brackets, a bar contacting the upper edge of the scapula was fitted to prevent vertical movement.
To analyze the vertical behavior of the CC suspension systems, two rings were placed in the clavicle (one outside and one inside the fixations), which were connected by two chains to the vertical movement clamp. The chains allowed the traction system to be placed at the same distance. The traction test was performed at a speed of 15 mm/min. Pre-tensioning was performed at 15 N before the displacement of the bar of the testing machine was initiated. The test was stopped when the tensile force dropped by 60 % of the maximum applied force (Fmax 60 %) or when mobility of the part or implant failure was observed. In each test, the maximum breaking force (in N) was obtained. Group I (control) was tested first, thereby obtaining the reference values for a healthy shoulder. Groups II and III were tested later.

Bonded samples (n = 16, per group) were evaluated for the SBS using a universal testing machine (ElectroPuls 3000, Instron, Norwood, MA, USA) with a flat-edge loading head. A shear load was applied to GICs at a distance of 1.0 mm to the dentine surface. The cross-head speed was set at 0.5 mm/min. The load was recorded at failure and then the SBS was expressed in MPa by dividing the maximum shear force (Newtons) by the bonded area. The failure mode of each fractured sample was determined by a light microscope at the magnification of 20× after SBS testing. The failure patterns were categorized as three types: adhesive failure (failure between GIC and dentine), cohesive failure (failure within GIC or in dentine), and mixed failure (partial cohesive failure and partial adhesive failure) [20 (link)]. To visualize the failure mode, some of the tested samples were sputter-coated with gold and observed under an SEM (Hitachi S-4800 FEG Scanning Electron Microscope, Hitachi Ltd., Tokyo, Japan).