An alternative putty/wash impression technique.

Conventionally, custom trays have been made in the laboratory on casts constructed from preliminary impressions. A spaced tray made in this way allows a uniform thickness of impression material of approximately 2 mm which is said to enhance the accuracy of the impression-taking procedure. A technique is described to fulfill this criterion without the need for a primary impression, by constructing a spaced putty custom tray inside the mouth.