Model ags 10kng

A universal testing machine (Model AGS-10KNG; Shimadzu, Tokyo, Japan) equipped with a customized fixture was used for micro-shear bond strength test. The specimens with resin cylinders were adhered to testing device with a cyanoacrylate adhesive, which in turn was placed in universal testing machine for micro-shear testing. A thin wire (diameter 0.2 mm) was looped around the resin composites cylinder, making contact through half its circumference and was gently held flush against the resin/non-carious sclerotic dentin interface. A shear force was applied to each specimen at a cross-head speed of 1 mm/min until failure occurred. The resin/dentin interface for test, the wire loop and the center of the load cell were aligned as straight as possible to ensure the desired orientation in the shear test force. The maximum load values (N) were recorded and the values of mean failure load were calculated for all subgroups.

A universal testing machine (Model AGS-10KNG, Shimadzu, Tokyo, Japan) equipped with a customized fixture for stabilizing the specimen and for gripping the resin cement cylinder was used for micro-shear bond strength test (Figure S1). Loading was applied with a cross-head speed of 0.5 mm/min until failure occurred. The maximum force (N) to produce fracture was recorded and the mean stress values on failure (in MPa) were calculated for all subgroups (Table 1).
The fracture surface of representative specimens was sputter-coated with gold–palladium (E-1030, Hitachi, Tokyo, Japan) and examined using scanning electron microscopy (SEM, S4800, Hitachi, Japan). Failure modes were recorded as: adhesive failure (failure occurring at the zirconia-cement interface) and cohesive failure (failure within cement). Failure areas of each mode were calculated as described previously [16] (link) and expressed as a percentage of the total bonding surface area for each subgroup.