Open-Tray Impression
An implant impression technique using a custom or stock tray with a window through which the impression coping screw is accessed and removed before tray withdrawal, allowing the coping to remain in the impression material.
Full Definition
The open-tray impression technique requires a perforated or windowed impression tray that allows the operator to loosen and unscrew the impression coping through the tray while it remains seated in the patient's mouth. Once the screw is loosened, the tray and impression material—with the coping embedded—are removed together. This method is preferred for cases involving multiple implants, divergent implant axes, or where maximum accuracy is required, as it minimises distortion from elastic recovery. Documents describing this technique should distinguish it clearly from the closed-tray (snap-on or pick-up) technique. Editors should note that all three words are hyphenated when used as a compound modifier.
Usage
Usage note: Hyphenate as 'open-tray impression' when used as a noun phrase and as a modifier. The synonym 'pick-up impression' is common in UK literature; 'direct impression technique' appears more frequently in academic papers.
In Context
- "An open-tray impression was selected due to the divergent angulation between the two posterior implants." — Prosthetic treatment notes
- "The manuscript inconsistently hyphenated 'open tray impression'; the editor applied the hyphenated compound-modifier form throughout." — Copy-editing note