ISO 21563:2013 pdf free

ISO 21563:2013 pdf free.Dentistry – Hydrocolloid impression materials
a) Determine whether the gypsum products [7.4.1 f)] comply with the initial setting time and detail reproduction requirements of ISO 6873. Do not use any gypsum that does not comply with these requirements.
b) Treat the inner surface of the slit mould [7.4.1 c], including the slit surfaces, with a thin film of the high vacuum grease [7.4.1 d)], and then use the clamping mechanism to close the slit.
c) Use any post-disinfecting agent [7.4.1 b], that may be recommended in the instructions for treating the impression before pouring the gypsum.
d) Position and temporarily fix the ring mould/impression material specimen assembly, lined surface down, in the rabetted recess of the slit mould and invert the assembly in preparation for pouring of the gypsum product.
e) Pre-proportion the water/gypsum mixing components using 120 g of gypsum powder along with the volume of water required according to the water/ powder ratio specified in the gypsum manufacturer’s instructions for use [8.2.3 c)].
Begin mixing the gypsum at one minute before the end of the time lapse permitted between removal of the impression from the mouth and the time recommended for commencement of pouring the model [See 8.2.1 e].
Upon completion of the mix, direct first increments of the gypsum mixture, via mechanical vibration, so that they will flow first down along an internal side surface of the mould, and then flow over the ends of the raised Lines a, b, and C on one side of the impression material specimen, and then be directed to gradually flow along and over the lines to their opposite ends. Continue adding increments thereafter until the mould cavity is slightly underfilled.
Unless otherwise specified by the gypsum or impression material manufacturer’s instructions, allow the poured impression gypsum assembly to set in the laboratory environment until 45 min after the initial setting time previously determined for the gypsum product in accordance with [7.4.2.2 a)]. Then separate the gypsum specimen from the assembly and begin the test procedure immediately thereafter.ISO 21563 pdf download.