Both upper and lower impressions are required for processing a case.
Impression material should have a longer shelf life and should be able to capture all details.
A number of materials can be used. Addition Silicone polyvinyl siloxane Impression material is the recommended material of choice.
Two step PVS impression material gives the best results when taken with a metal perforated impression tray. The impressions are to be shipped WITH the trays.
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