ISO 15854-2021 pdf free download – Dentistry – Casting and baseplate waxes (ISO 15854:2021).
5.6Behaviour on softening (Type 2)
The wax shall soften without becoming sticky or crumbly and shall be mouldable without breaking ordelaminating when tested in accordance with 8.6.
This requirementshall not apply to baseplate preforms where a suitable square test piece cannot be cut.5.7Residue on artificial teeth (Type 2)
The wax shall not leave a visible residue on either ceramic or synthetic polymer teeth when tested inaccordance with 8.7.
5.8Behaviour of colouring material (Type 2)
The colouring material shall neither separate from the wax nor impregnate the gypsum mould whentested in accordance with 8.7.
5.9Adhesion on storage (Type 2)
Adhesion due to storage of the wax shall be such that, when tested in accordance with 8.8, there shallbe no evidence of damage to wax surfaces. Wax and separating paper surfaces shall separate cleanlyand readily.
NOTE The separating paper might not cover the whole area of the wax sheet.5.10 Residue on ignition (Type 1)
lf the manufacturer does not state a value for the residue on ignition, the value as determined inaccordance with 8.9 shall be no greater than 0,10 % by mass.
lf the residue on ignition is greater than 0,10 % by mass, this value shall be stated by the manufacturerand the value as determined in accordance with 8.9 shall be not more than 20 % greater than thatstated value.
5.11 Biocompatibility
See IS0 7405 and IS0 10993-1 for guidance on compatibility in respect of waxes that are offered for usein the mouth or that are not specifically excluded from that application.
6Sampling
The amount of material procured for testing shall be at least 250 g for Type 1, or 500 g for Type 2, andfrom one batch, and one packet where possible. This material shall be obtained on the open marketunannounced and thus taken randomly from stock.
7Test methods — General
7.1 Ambient temperature
Unless otherwise specified in this document, all test piece preparation and testing shall be conducted atan ambient temperature of (23 ±C.Where necessary and appropriate, all material shall be allowedto equilibrate at this ambient temperature before testing for at least 24 h.
7.2Apparatus function verification
All accessories, instruments and equipment shall be examined before use to ensure that they are inacceptable working order, appropriately calibrated, and complying with specifications stated for themin this document, as appropriate.
8Test methods – Specific8.1 Visual inspection
Carry out the inspection at an illuminance of at least 1000 lux and at a distance not exceeding 250 mm.Aperson making the inspection shall have nominally normal visual acuity.Corrective (non-magnifying)untinted lenses may be worn.
8.2Flow
8.2.1 Principle
The relative change in length of the test piece under a given load in a specified time is taken as a proxyfor the inverse of viscosity.
8.2.2Apparatus
8.2.2.1 Micrometer screw gauge
Micrometer screw gauge with a range of at least 10 mm, being readable and accurate to 0,005 mm orbetter, equipped with flat, parallel anvils at least 6,5 mm in diameter and a non-rotating spindle.
NOTEAvoidance of indentation of the wax test piece is essential.
8.2.2.2Flow-testing instrument
A flow-testing instrument, such as the one shown in Figure 1, consisting of the following components:- weight (see Figure 1, Key 1);
shaft, which can move freely in its supports, lubricated as necessary (see Figure 1, Key 2);
upper platen, metallic, minimum diameter 50 mm, lower surface flat and smooth, rigidly attachedand normal to the axis of the shaft (see Figure 1, Key 3);
base plate, metallic,flat smooth and parallelto thelower surface ofthe upper platen(Figure 1,Key 4);measuring dial gauge or similarly functional instrument, with a range of at least 10 mm, readableand accurate to 0,005 mm or better, and rigidly supported [optional)(see Figure 1,Key 5);
– locking screw or equivalent device (required if the dial gauge is used) (see Figure 1, Key 6).ISO 15854 pdf download.