Fractured Screw: What Are My Chances?
Dr. H. asks:
I am an Australian dentist. I recently went to place a screw-retained abutment and cement-retained crown on the upper right premolar.
The surgeon had placed a Branemark narrow platform 15mm length dental implant. I screwed down the abutment and started to torque it down with my Nobel Biocare torque wrench to 35Ncm as advised. I was surprised as I did this that I could not torque the screw down to the desired setting and the torque wrench kept engaging the screw and turning but just short of the 35ncm. Then the screw fractured. How is this possible?
At first I thought I may have used the lab screw but this was not the case. I then thought that a narrow platform screw may only go to 20 Ncm but the literature does not mention this anywhere.
What are my chances of backing this screw out? It fractured about 0.5mm into the implant. The screw retrieval kit arrives tomorrow, but reading some posts about using it describe long ,difficult and tedious attempts to back out the screw. Any helpful hints and comments telling me I will get the screw out would be nice. Thanks.