Clinical significance of complete seating of open tray impression coping – Verification jig
T ASMAA; E PAROUTOGLOU; S SOMJI; J SHI ; S PARK; C YEH; J PUNIA; N BALUBAID; A HOTCHANDANI; M MANASSE; S CHO
The accurate transfer of intra-oral information for extra-oral use is the purpose of impression taking and is the first step for a successful restorative procedure. Impression techniques can be either pick-up, in which the guide pin is untightened prior to removing the tray via an access window in the tray and the impression coping is subsequently retained in the impression, or transfer, where the coping is transferred from the mouth to the impression with the impression analog. Studies have shown that the pick-up impression is more accurate than the transfer technique.
To accurately replicate the implant position for adaptation of an abutment that will completely engage with the implant, a pick-up impression is taken, with an impression coping, for registering the position of the implant or abutment in the impression, and a guide pin, to secure the coping to the implant during the impression taking procedure, and later to the implant replica in the master cast. The impression coping and guide pin, once seated, must be verified with a radiograph to confirm the coping has fully engaged with the implant.
There are several issues that may affect seating of the impression coping such as soft tissue interference, the impression coping size, angulation, proximity or contact with adjacent teeth, damage to the coping, and differences between seating in an external versus internal connection implant.
The purpose of this report is to present a verification jig to ensure complete seating of the impression coping with the implant, without need of confirmation with a radiograph.