Implant Fixture Level Impression - Open Tray Technique
Posted on 07/19/2011
Continuing on our previous topic, today we will explore the steps involved in taking an implant fixture impression. Broadly, there are two techniques to take an implant fixture impression: (1) OPEN TRAY TECHNIQUE, (2) CLOSED TRAY TECHNIQUE.
The OPEN TRAY TECHNIQUE is designed to keep the impression transfer coping in the impression at all times. This is typically a more accurate technique since there is no room for error of position of the impression coping, although it is a more difficult technique - especially on maxillary posteriors. The technique utilizes an open tray impression coping and long, thin screw. One of the discernable features of the open tray impression coping is that it is typically shorter than the closed tray coping and has a standard thin screw head - i.e. no ball top. The procedure for taking the impression is follows:
1) Uncover the implant by unscrewing the healing cap
2) Secure the open tray impression coping to the implant using the long thin screw. The screw should be longer than the impression coping and should stick out beyond the impression coping (away from the gingiva) by at least 2mm for easy retrieval.
3) Make a screw access hole in the impression tray in the area of the implant to allow for the unscrewing of the impression coping from the back of the impression.
4) Add medium or heavy body VPS (vinyl polysiloxane) impression material around the impression coping to ensure secure fit. Light body impression material is not advised as the impression coping may move after removal.
5) Fill in the remainder of the tray with medium or light body impression material
6) Allow for impression material to set based on manufacturers guidelines - but at least 6 minutes.
7) Unscrew the impression coping screw from the back of the impression.
8) Remove the impression tray with the impression coping securely in place.
9) Replace the healing cap back into the implant.
10) Place the screw back inside the impression coping (from the back of the tray) and add wax or tape to the screw to ensure the screw does not fall out from the back.
11) Place the impression in a bag separate from the bite and the counter model to ensure the parts do not get lost.
The OPEN TRAY TECHNIQUE is designed to keep the impression transfer coping in the impression at all times. This is typically a more accurate technique since there is no room for error of position of the impression coping, although it is a more difficult technique - especially on maxillary posteriors. The technique utilizes an open tray impression coping and long, thin screw. One of the discernable features of the open tray impression coping is that it is typically shorter than the closed tray coping and has a standard thin screw head - i.e. no ball top. The procedure for taking the impression is follows:
1) Uncover the implant by unscrewing the healing cap
2) Secure the open tray impression coping to the implant using the long thin screw. The screw should be longer than the impression coping and should stick out beyond the impression coping (away from the gingiva) by at least 2mm for easy retrieval.
3) Make a screw access hole in the impression tray in the area of the implant to allow for the unscrewing of the impression coping from the back of the impression.
4) Add medium or heavy body VPS (vinyl polysiloxane) impression material around the impression coping to ensure secure fit. Light body impression material is not advised as the impression coping may move after removal.
5) Fill in the remainder of the tray with medium or light body impression material
6) Allow for impression material to set based on manufacturers guidelines - but at least 6 minutes.
7) Unscrew the impression coping screw from the back of the impression.
8) Remove the impression tray with the impression coping securely in place.
9) Replace the healing cap back into the implant.
10) Place the screw back inside the impression coping (from the back of the tray) and add wax or tape to the screw to ensure the screw does not fall out from the back.
11) Place the impression in a bag separate from the bite and the counter model to ensure the parts do not get lost.
