Closed Tray vs. Open Tray Impression Technique?


Dr. L asks:
I have treatment planned a patient for a maxillary full arch fixed partial denture who has 8 implant fixtures. I generally used a closed-tray impression technique to pick up the transfer impression copings. But in this case I am concerned that the impression tray will lock on the transfer impression copings and I may have to cut off the tray. I am planning therefore to use an open tray impression technique for the first time. Any thoughts? Does anyone have any clinical tips on the open tray technique?