I have a problem with a broken screw in a 3i Implant. The remaining screw fragment is not loose and I have tried Ultrasonic Tartar and Stain Removal solution soak in the implant for lubrication. I have used a temporary plastic tube coping in the implant to guide a modified latch grip slow speed round burr in reverse to try to back out the piece with no success to this point. Does anyone have any suggestions for me to try? I have seen a couple of kits for purchase that seem to have a similar scenario to my round bur with tube. Any help would be greatly appreciated.