When You Torque the Implant Abutment Screw

Have you ever been concerned that when you torque the implant abutment screw at the time of final abutment placement, the implant itself may rotate and separate the implant from the bone? To prevent the rotational forces from being transmitted to the implant, try the following technique. Have your assistant hold the abutment with a hemostat while you torque the screw to the manufacturer's recommended tightness for that particular implant and screw. By holding the abutment with a hemostat, the force used during tightening is applied to the screw, not to the abutment or implant. This should mitigate any damage occurring to the integration that has occurred between the implant and bone.

Comments

Mark Venditti
October 31st, 2013

Excellent, thank-you. Mark

Andy
October 31st, 2013

Any concern about possible fracture of a zirconia abutment?

Bob Winter
October 31st, 2013

You aren't actually clamping the hemostat tightly onto the abutment, rather you are holding it gently so that the abutment does not rotate. You should not be using a lot of counter-rotational force or pressure to keep it steady.

Steve Lee
October 31st, 2013

I always assumed the implant and the abutment are designed to handle a momentary torque at recommended levels. What does that say about our faith in the osseointegration and the integrity of the implant and abutment material if we're concerned about torquing the system a few times? Should we also be concerned about how much force is being applied to the abutment by the hemostats? And what if the timing of the assistant's counter rotational force doesn't exactly coincide with our torquing force? Will the system then be subjected to back and forth torquing? Is that worse than unidirectional torquing? All this is tongue in cheek, of course. I'm not really worried about it all. The one time I actually turned an implant, I figured it was good to find out earlier rather than later that it wasn't well osseointegrated.

Mike
October 31st, 2013

If the implant turns at a mere 30-35 N-cm then there are bigger problems ahead that the simple holding of the abutment will mask. Sorry but this simply will not work and it is impossible to convey to the assistant the amount of "holding" that is required especially where a thin zirconia abutment is used. Never did this and never had a good integrated implant turn or move on a simple torquing of the abutment.

Gerald Benjamin
November 1st, 2013

Or have your lab fabricate a placement jig. That is the ONLY way to do this right!

Robert Yetto
November 1st, 2013

While I agree with my good friend and colleague Dr. Benjamin, we must not lose sight of the comments of Drs. Lee and Mike - if the torque involved in seating the abutment were to move the "osseointegrated" implant, there are bigger problems to be dealt with than can be overcome by this technique.

Toufic Boutros
November 1st, 2013

That's exactly what I do acrylic placement jig for precision of placement, rapidity and torquing. Anyways I do not worry about osseointegration integrity of the implant at this time but long time before, it is osseointegrated OR not !! And if it is then no worry about tne 35 N torque.

Ben Schultz
November 1st, 2013

I am in complete agreement with the peanut gallery here. If the patient feels anything when torquing the abutment screw, the fixture probably isn't integrated, and if they don't, 35Ncm won't matter. But my implant lab, as well as 3i, recommends 20 Ncm for zirconia abutments. 35 can cause it to fracture, and that "crick" is not something you want to hear. As an aside here, zirconia abutments wear titanium from the fixture, which is what the grey is on the abutment when it is removed. This may be only a theoretical problem, but I'd hate to see the tooth start moving when the implant is integrated and the crown is firmly cemented...

Zvi Fudum
November 2nd, 2013

I think the torque from the mousquito is more dengereous then the torque from the driver.

Bob Winter
November 8th, 2013

Great discussion. I agree with many of the thoughts that have been expressed here. There are generally no “perfect” techniques; each come with risks and benefits. Determining if any technique fits into your treatment philosophy will dictate if it is implemented in your practice. For example, if there is a concern holding a zirconia abutment with a mosquito hemostat, would there not be a high concern that the abutment would not resist the functional forces applied to it? If you hold the abutment with a hemostat and the implant moves in some way, would it not mean there is a more serious problem? Would you not want to know that at this time? A very high percentage of implant abutments are not inserted with a placement jig, something I would highly recommend. The technique I described is simple with no additional costs involved to implement. Why do you wear a seatbelt in a car? It is done as a precautionary measure to help restrain us in the event of an accident. Who wants to risk not wearing their seatbelt?

Muna Strasser
January 10th, 2014

great point!

DR Derry Rogers
January 27th, 2014

Good discussions gentlemen Remember if the Perio needs to back out an integrated implant due to incorrect position or screw fracture internally that cannot be accessed, the forces they talk about are 90-120nm On the basis of this we gave up holding the implant for torque testing a long time ago and use tapping sounds and patient perception if they feel the force or the implant moves and comes out if the testing forces are moving it above 35 nm

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When You Torque the Implant Abutment Screw

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