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Print This PostDr. Nimchuk asks:
It has been purported that excessive insertion torque may lead to ineffective osseointegration due to bone compression and necrosis at the cellular level.
While most references refer to an optimum insertion torque of about 45 newtons it has been my experience personally and observation of others that many times substantially more force than this is commonly applied particularly with tapering dental implant systems.
Is there any real evidence of what may be considered excessive insertion torque and is there any true clinical relationship to insertion torque forces and integration? I have a feeling this is another one of those rationalizations that have taken on a state of dogma and is not really substantiated. I’d be interested to hear what other experience in the field has been and what opinions are on this matter. Please leave your comments below.
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17 Responses to “ Insertion Torque and Osseointegration ”
Nobel…..never over 45nc
Isn’t interesting that I believe only Nobel and Camlog have a torque device used with placement.
No one is really talking about tissue necrosis from over compresion. Look at the use of osseotomes in the maxilla. I believe you get away with it because of the type3 and 4 bone.
I did serveral animal research, and we found with a torque above 50 Ncm more failures than with lower insertion torque. The insertion torque above 50 Ncm is something different to osteotome technique, because here we allow the bone to be released prior to the implant placement.
Neugebauer J, Traini T, Thams U, Piattelli A, Zoller JE. Peri-Implant Bone Organization Under Immediate Loading State. Circularly Polarized Light Analyses: A Minipig Study. J Periodontol 2006;77(2):152-160.
Perhaps the reason why one needs to avoid exceeding 45NCm insertion torque with Nobelpharma internal connection implants is that there is a danger of rupture of the implant. The Camlog design is much stronger and considerably more precise.
In trauma surgery with respect to mandible fractures, previous AO priniciples recommended the use of dynamic compression plates to compress the fractured bone segments. This compression led to more non-unions and healing complications. Now currently, we approximate fractures the best we can and fixate them in a manner that allows for immobility with the use of ridgid fixation (in most fractures–not all). We no longer use the compression theory. Therefore, it is not a big leap to believe increased torque at some level will end up with more complications. The priniciples of osseointegration and fracture healing are very similar processes. Immobility is the critical factor in healing. I can remember back in the early days, we made an osteotomy and “dropped the implant in the hole”. Although some failed, the strong majority of them healed just fine.
I agree with the last post and that of Jeorg. The only reason we tend to want to torque the implant is to get the primary stability and IMMOBILITY in presence of indirect (through bolus of food) masticatory forces. In cases of loading after integration, 20-25 Newtons is the ideal (in my experience).
In cases of immidiate partial loading(out of occlusion temporaries) 30-35 Newtons is necessary to insure immobility in oral environment. I have had 3 implants that I happily torqued to 50-55 Newtons fail with no other apparent reason.
You can predetermine your torque using your drilling machine setting. No need for any special equipment.
One of the presenters at the ‘04 Zimmer conference in Spain cited a study of the tappered screw vent where insertion torques of over 150Ncm were achieved. No implants failed to integrate. Increased speed, however, at high torque can create excessive heat.
Camlog is the best concevied connection for Implants today,because Dr. Kirsch is fully in implants since years…other companiĆ©s want to apply torque to existing implants line,even when they did not consider Imediate loading in the past.It is mecanically better a lobe than a triangle…
Nobel connection users will experience more difficulties than Camlog connection.
I do find it contradictory when I read in journals such as JOMI that 45-50 NcM is recommended for immediate loading, while reps and colleagues suggest that the same torque can lead to pressure necrosis. I have had no failures with implants torqued up to 45 NcM.
Paulo Trisi presented a paper at the San Diego ICOI meeting which tested the torque to failures relationship. He concluded that the more torque, the better, up to the limit of the failure of the titanium. His study is due to be published this month. I don’t have a way to measure over 50 ncm, so I do worry about breaking or distorting the implant at high insertion torques.
We have published a clinical prospective study , involving 98 conical implants with 5.0mm diameter instaled under a 80Ncm torque force protocol in maxilla and mandible assorted sites. Standartized clinical and RX evaluation after the osseointegration period presented 94 of the cases meeting all current criteria of success. Only one of the the 4 failures presented minor reabsorption - a 5.0mm x 10mm located in posterior mandible. No evidence of clinical and RX alterations were found. It is also interesting to remark that the forces applied at orthopedic implant procedures, that involve higher volume devices, may be much higher than 45Ncm.
I regularly insert Replace Select at forces greater than 45Ncm and havn’t noted any problems with implant diameter of 4.3mm and larger. I’ve had one 3.5mm fixture fracture at the collar during insertion so I’m always super cautious not to exceed 45Ncm with these narrow platform implants. I’m not aware of any instances of bone necrosis related to exceeding 45 Ncm torque.
It still amazes me that a clinician will use a system that has a protocol that tells the user not to exceed 45ncm. Any other of the top 10 implant systems’protocol will instruct the same Ncm on insertion not specific to diameter. This means there is a fracture problem with the Nobel 3.5 NP. Design problem. Titanium problem. Whatever one may call it, the problem is there. Have this discussion devoid of Nobel 3.5 NP and maybe one may get some clarity.
I agree that there is a problem with the Nobel 3.5 Select. I have heard of many fracturing upon placement. Tiunite is is pure grade 4 titanium and is much softer than alloys. Adding threads to the collar (Groovy) will further weaken the collar and we may see more fractures. Stay tuned…
I cannot comment on groovy or any other nobel implant. Fractures occured when I utilized the the 3.5 replace select nobel system. It did not happen often but twice was enough. The second resulted in a horrible situation with the patient.
Has anyone tried the bone compression kit offered by MIS to improve initial stability in poor bone quality? Does this approach fall into the (now defunct) compression theory mentioned in a previous post?
I have used the new MIS Bone Compression kit / Sinus lift kit. Nice! The bone compression kit works well. I especially like the sinus lift protocol - much better than the osteotome technique - my patients hate the hammering part. Instead this system uses a rotary osteotome - I found it to be very patient friendly. I used it with Straumann implants.
I used Zimmer TSV as self tap and put a lot in posterior mandible with over torque pressure to the extend that one with fratured mount occur and the implant prooved successful and restored. Non engaged and over torqued and failed.
Again I used a fully selftap implants and found more sucess in all area of the oral cavity .
This concluded that in my openion the fact of compression and failure of high torque is invalid as I was expected.
Prof.Samir Koheil
Fellow of ICOI
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