A cast is poured with polysulphide impression material, but details are not achieved in cast. For achieving that what should be done?
Absence of ﬁne details in cast poured with polysulﬁde impression materials indicates its hydrophobic property.
A nonionic surfactant can be added to the impression materials in the manufacturing process to produce a degree of hydrophilicity to the surface of the material.
The beneﬁcial eﬀect of optimal surfactant mixing at the time of manufacturing is not reduced by rinsing the impression prior to pouring, so ﬁne details can be achieved on cast too.
Adding surfactant to gypsum
Mixing surfactant to impression material
Spraying water to gypsum
Spraying water + mixing surfactant to gypsum