Thomas, a dentist, asks:
I torqued a transfer impression coping to 20 Ncm as per directions from the dental implant manufacturer. The transfer coping screw had an internal hex in its head. After making my impression index, I attempted to unscrew the transfer coping screw. The angles of the internal hex rounded off and I could not engage the internal hex with the torque wrench. Has this ever happened to anybody? What did you do to get it out?
Comments are closed.
NanoGen is a nanotechnology-based bone graft. As compared to traditional calcium sulfate, NanoGen provides the stimulation for bone regeneration over a much longer period.
Find more candidates for Denture Stabilization by showing a high quality video of the MDI procedure.
ZEST Anchors pioneered self-aligning attachments to combat the damage done by the improper seating of overdentures.
Surgical Guides are today’s dental implant surgery state of the art. Get Faster, Hassle-Free Guided Surgery Starting at $399.
Acquire a strong theoretical background in implant dentistry, and gain practical experience, by placing dental implants on live patients.
Working in teams of 3 participants, the Q-Implant courses include 40 hours of practical surgery aiming at intensifying theoretical knowledge and gaining practical experience in Implantology. Watch a video of the Q-Implant Marathon!
I managed to round off the internal shape of a Straumann healing cap, about 8 years ago. I solved it by very carefully cutting a screw head shape into the remaining metal and then using a watchmaker’s screwdriver to remove the cap.
You possibly need to combine your skills and thinking with that of an engineer who has snapped off a stud in an engine block.
Make sure it is not your hex driver that has rounded off. I have replaced a number of drivers due to rounding of the hex but never had an impression coping screw rounded out. Try a new driver to verify this.
I once rounded off the internal hex of an abutement when I was removing a porcelain/metal crown from the implant abutement. (Diamond too close to the hex). Most implant vendors have a ‘easy-out’ type of instrument very similiar to what mechanics/plumbers/etc use to remove broken screws. Basically, it’s a left hand thread that engages the stipped hex when you turn the wrench counter-clockwise. Works like a charm. About fifty bucks.
Per the above post, also check your driver first.
Try an new sharp rosenbur in slow but high torque in a reversed mode, it will often do the trick.
It happened to me two days ago!
I managed to cut the head of the transfer with a diamond bur, leaving intact the internal screw.
Then, with a universal clamp, i could easily unscrew the transfer.
Isn’t it unusual to torque an impression coping/transfer screw to 20Ncm?
The information I pass on to my accounts (also from the implant manufacturers) is to secure the screw with finger pressure only.
The various solutions posted are well worth remembering and I will pass those on as needed.
I agree. I would never torque an impression pin. It is not necessary. Secondly, Hex drivers are not all a like. Some only have a milimeter of hex, others 2mm of hex. Off brands usually are smaller and do not fully engage the female screw hex.
Lee, I have also used the “easy out” they do work in most situations.
The rosenbur idea sounds interesting. What is a rosenbur, anyway?
Just to be sure not to overlook the obvious, the Straumann System uses a Straumann SCS Driver. It may seem compatible with an .048 internal hex driver but it is not. It is also not compatible with Nobel Replace Select system