BS EN ISO 1797:2017 pdf download – Dentistry — Shanks for rotary and oscillating instruments
5.1.4 Surface roughness
The surface roughness, Ra, for shanks made of metal, tungsten carbide or ceramic material, shall be for the following, as shown in Figure 5 to Figure 8:
a) Type 1, Type 2, and Type 4: ≤ 1 µm;
b) Type 3: ≤ 0,5 µm.
The surface roughness for polymeric materials Ra, shall be ≤6 µm for all types.
Test in accordance with 7.4.
5.1.5 Location of marking
The location of the marking, if envisaged, should be outside the fitting length.
If the marking is applied within the fitting length, l 1 , the outside diameter of the shank with the marking shall not exceed the effective diameter of the shank.
Testing shall be carried out by visual inspection.
5.1.6 Colour code of plastic shanks
The colour of the plastic shanks shall comply with the colour code of the instrument for which it is used.
Testing shall be carried out by visual inspection.
5.2 Material requirements
5.2.1 Shanks made of metal or tungsten carbide
5.2.1.1 Type of material for metal or tungsten carbide shanks
The exact type of metal or tungsten carbide material and the treatment given to it are at the discretion of the manufacturer.
5.2.1.2 Hardness for metal or tungsten carbide shanks
The hardness for shanks made of metal or tungsten carbide shall be not less than 250 HV5.
Test in accordance with 7.5.
5.2.2 Shanks made of ceramic materials
5.2.2.1 Type of material for ceramic shanks
The exact type of ceramic material and the treatment given to it are at the discretion of the manufacturer.
5.2.2.2 Hardness for ceramic shanks
The hardness for shanks made of ceramic material shall be not less than 1 400 HV0,5.
Test in accordance with 7.5.
5.2.3 Shanks made of plastic materials
5.2.3.1 Type of material for plastic shanks
The exact type of plastic material and the treatment given to it are at the discretion of the manufacturer.
5.2.3.2 Tensile test for plastic shanks
The tensile strength for shanks made of plastic shanks shall be not less than 130 MPa.
Testing shall be carried out in accordance with 7.6.
5.2.3.3 Heat resistance and colour stability for plastic shanks
This requirement does not apply to single use instruments.
Shanks made of plastic material shall show no signs of deformation and there shall be no recognizable colour change after testing.
Testing shall be carried out in accordance with 7.7.
5.2.3.4 Stability against swelling and chemicals for plastic shanks
This requirement does not apply to single use instruments.
Shanks made of plastic materials shall not swell beyond the specified tolerance range of Figure 5 to Figure 9 when treated with disinfecting or sterilizing solutions as recommended by the manufacturer.
Shanks shall meet the tolerance range of Figure 9 when sterilized according to 7.7.
Testing shall be carried out in accordance with 7.1 to 7.3.
5.2.3.5 Marking
Marking shall be resistant to reprocessing procedures as disinfection, cleaning and sterilization for at least five cycles according to the manufacturer’s instructions, unless the instrument is marked for single use.
6 Sampling and pass/fail evaluation
Take 10 instruments at random from the validation batch and test them according to the method described in Clause 7.
If eight or fewer instruments pass, the product fails.
If nine instruments pass, test 10 additional instruments. When 10 additional instruments are tested, all 10 additional instruments shall pass for the product to comply.
7 Measurement and test methods
7.1 Shank diameter
Measurements of the shank diameter shall be made in accordance with ISO 8325 with suitable measuring devices. The manufacturer shall validate that the accuracy of the measuring device is applicable.
The shank diameter, d 1 , shall be measured by traversing the length, l 1
7.2 Other dimensions
Measurements of other dimensions shall be made in accordance with ISO 8325 with suitable measuring devices. The manufacturer shall validate that the accuracy of the measuring device is applicable.
7.3 Shank cylindricity
Use a test method based on, for example, run-out test methods or straightness measuring techniques with at least three point locations during the qualification process.BS EN ISO 1797 pdf download.