ISO 9693:2019 pdf free.Dentistry – Compatibility testing for metal -ceramic and ceramic-ceramic
systems.
5 Sampling
5.1 Metallic substructure material
The sample shall be adequate for preparing the test specimens in accordance with this document. All of the metallic material shall be from the same lot and unused.
5.2 Ceramic substructure material
The sample shall be adequate to prepare the specimens for testing in accordance with this document.
All of the ceramic material shall be from the same lot.
5.3 Veneering ceramic
The sample shall consist of a sufficient amount of veneering ceramic to carry out all tests in accordance with this document, including the tests performed according to ISO 6872. Perform the tests on the colour/shade variant most commonly used. AIll of the material tested shall be from the same lot.
Prepare six specimens (either six metallic or six zirconia) with a size of (25 ± 1) mm x (3 ± 0,1) mm x (0,5 ± 0,05) mm in accordance with the manufacturer’s procedure for processing the substructures for prostheses. Condition the specimens and follow the procedure described in the instructions for use (e.g. cleaning, sandblasting, oxidation).
Before applying the ceramic to the test specimens, calibrate the furnace according to the manufacturer’s recommendation and test-fire the ceramic material to obtain the appropriate firing grade and surface gloss of the veneering ceramic materials. If necessary, adjust the firing temperatures or holding times.
According to the instructions for use, add dental veneering ceramic to each specimen to form a total ceramic thickness of (1,1 ± 0,1) mm after firing (see Figure 1). The ceramic layer shall have a rectangular shape and extend the full 3 mm width of the substrate.
If necessary add additional dental veneering ceramic to obtain the required thickness and shape, and fire it. Carefully trim the rectangular shape with a disc. If necessary remove ceramic from the side of the substructure material in order to keep its overall shape.
Submit each specimen to a glaze firing in accordance with the instructions for use.
The fired specimens are placed in the bending apparatus with the veneering ceramic positioned symmetrically on the side opposite to the applied load. The force is applied at a constant cross-head speed of (1,5 ± 0,5) mm/mm and recorded up to failure. The fracture force Ffajl (in newtons) for each of six specimens is measured for specimens failing by a de-bonding crack occurring at one end of the ceramic layer. Specimens failing by cracks in the middle of the ceramic layer shall be replaced until six appropriate specimens are obtained.
The failure (abortion) criteria is the abrupt decline of the force by 5 % or more.
Multiply the fracture force FfajI with the coefficient k. Determine coefficient k by reading from Figure 2. The coefficient k is a function of the thickness of the metal or ceramic substrate d (0,5 ± 0,05) mm, and the value of Young’s modulus Ez of the metal or ceramic substrate.The following two procedures (6.5.3 and 6.5.4) shall be taken as examples on how to conduct the test properly. The test set-up may however be modified according to individual material combinations tested and overall experience of the test house involved. The whole detailed test set-up and result shall be part of the test report (see Clause 7).ISO 9693 pdf download.