BS EN ISO 3107:2011 pdf download – Dentistry — Zinc oxide/eugenol cements and zinc oxide/ non-eugenol cements (ISO 3107:2011) 7.3.1.3 Cabinet, as specified in 7.2.1.1. 7.3.1.4 Micrometer or similar measuring device, accurate to 1 μm. 7.3.1.5 Mechanical tester, capable of being operated at a cross-head speed of (0,75 ? 0,30) mm/min or at a loading rate of (50 16) N/min. 7.3.2 Preparation of test specimens Condition the moulds (7.3.1.1), screw clamps (7.3.1.2) and top and bottom plates (7.3.1.1) at (23 ? 1) °C. After mixing in accordance with the manufacturer’s instructions, pack the cement, to a slight excess, into the split moulds within 1 min of the completion of mixing. In order to consolidate the cement and to avoid trapping air, it is advisable to convey the largest convenient portions of mixed cement to the mould and apply to one side with a suitable instrument. Fill the mould to excess in this manner and then place the mould on the bottom plate and pack the cement, such that the excess is expressed. To facilitate the removal of the hardened cement specimen, the internal surface of the mould may be evenly coated, prior to filling, with a 3 % solution of micro-crystalline or paraffin wax in pure toluene. Alternatively, a thin film of silicone grease or polytetrafluoroethylene (PTFE) dry film lubricant may be used. Remove any extruded cement, place the top metal plate in position and squeeze together. Put the mould and plates in the clamp (7.3.1.2) and screw tightly together. Not later than 2 min after completion of mixing, transfer the whole assembly to the cabinet (7.3.1.3), maintained at (37 ? 1) °C. One hour after completion of mixing, remove the plates, and prepare the surface of the ends of the specimen plane, at right angles to its long axis, using a small amount of 45 μm silicon carbide powder or similar abrasive, mixed with water (ISO 3696, grade 2) on a flat glass plate. Keep the specimen wet during preparation. Alternatively, use an equivalent grade of abrasive coated paper and water (ISO 3696, grade 2). Keep the ends of the specimen flat by rotating the specimen one quarter turn every few strokes. Remove the specimen from the mould immediately after surfacing and examine for air voids or chipped edges. Discard any specimens with these defects. Immerse each specimen in distilled or deionized water (ISO 3696, grade 2) and maintain...
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