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 companiés 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

It is fairly accurate to suggest that all conversation that meanders towards "Implant systems" and not "Implant designs", while discussing bone OVERLOAD (high Torque)during either drilling or while inserting Implants may be devoid of a significant amount of scientific thinking. As Implant designs within a certain Implant system, are likely vary in their thread design, thread pitch, surface treatment, Collar height, Platform configuration etc.. all of which are variations incorporated to allow for more choice to be available within the same Implant system, to facilitate the user(clinician) to make a calculated choice regarding the kind of Implant'design' he or she would like to employ in the given situation. As this may vary from the very dense posterior Mandible to the extremely Cancellous Posterior Maxilla, and Immediate Extraction Implants, Graft sites for implants, sinus Lift sites for implants etc making up the milieu of rather unpredictable bone quality types in between, it is imperative that a choice of Implant design be customized to the situation one is faced with. While the Tapered Screw Vent is a fantastic Surgical thread design, that enables its almost unrestrained insertion into all kinds of bone , the Square thread design (of the older BioHorizons Square thread)would mandate a Screw tap to precede its insertion, particularly ion dense bone. The Nobel replace Select tapered has a combination of the Reverse Buttress / V thread design coronally and Square threads more towards the middle and apical portions of the implant. This being the case, it is natural to expect undue compression during placement in dense bone. If Osteolysis secondary to Overcompression happens it will undoubtedly be seen in the Mandible more frequently than in the Maxilla, with Square thread designs more than in the V-thread or reverse Buttress thread designs. Hence, it would be prudent to suggest that if NPs have 'failed' in dense bone, they were grossly over-torqued without a doubt, and if the bone was so severely dense it would undoubtedly offer such great resistance that would cause the thin rim of metal (as in case of aNP implant) to yield. This would probably not happen as easily with an implant with V-thread design as opposed with the ease with which it would in an implant with square threads as its feature. Cheers

On May 11, 2010, a periodontist placed a one stage implant of #30, just 3 days after flap surgery in the immediate area to the end of the right mandible. The pain was/is unending, day and night causing sleep deprivation. He dismisses the pain, tells the patient to take pain killers and refers the patient to oral surgeons at the dental school he taught at. The periondontist refuses to remove it, insisting he has done thousands of implants for 25 years and nothing is wrong with it. The patient(me), goes to his first referral June 17, before Osseo integration takes place. She gets the "everything is normal," no reason for pain, letter. The patient, in excellent health, does not take, or tolerate any meds/ drugs, maintains a healthy balanced diet and outdoor lifestyle. The oral surgeon wants to prescribe a daily medication for the masseter muscle, that he insists is the cause of pain. The patient refuses the prescription. Still in excruciating pain, the patient again requests implant removal, is dismissed with another referral, to another "titled" oral surgeon, at the same teaching hospital. Patient remains "bone shivering pain" and insists on implant #30 removal. August 23, the implant periondontist takes another x-ray, insisting it looks great, and his implant record of thousands in 25 years, is perfect. The patient again, describing the compression pain and how it radiates to the end of the right mandible from under #30. It feels like its at a compound angle, leaning towards 29, and the tongue, it cannot bear the slightest pressure/compression, either from tongue or a piece of lettuce, touching it. He then applies 45n torque, telling the patient she is not qualified to diagnose any implant problems. Dr. removes the screw and replaces it with a thin screw cover, below the gum line. Insists patient see his second referral and dismisses his patient, saying he can do nothing more for her. Since the small screw replacement, the pain diminished, and the patient can sleep more than an hour or two, without ice. There is still an implant presence, with creepy invasive, claw tugging, discomfort. The 30 area cannot tolerate the slightest pressure, from a fallen piece of soft food. The patient informed the implant periodontist, that implant #30, could never be load bearing. Now the patient is stuck with an imbedded piece of Titanium, that will never hold a crown and a dentist who refuses to remove it.

I have over 30 years of experience and one of the cardinal "rules" for me has been that bone does not like pressure (or temperature rise during placement), either from within or external i.e. dentures and partials. I take strong exception with the idea that these screw type implants can be seated to 40, 45 or even 70 ncm and left that way. There is nothing gained by leaving that much torque on the implant. I see nothing wrong with taking it to whatever torque you wish, (to prove the stability of the implant) but turn your torque wrench over and back off by a small amount to relieve the pressure on the bone. The only time I have had post operative pain is when I have not relieved the pressure. In one case the postoperative pain was extreme and ultimately the implant was lost. In another, the pain slowly diminished and then stopped after about 6 weeks and I went on to activate in 60 days however , I am very suspicious of that implant. I have placed and restored over 8000 implants with that protocol. These extreme torques do not help the integration, but quite the contrary, it may well interfere with it. I think the implant should be in the bone passively. Place the implant, torque to whatever you want, relieve the pressure and get out. This way the bone does not even know you were there and the postoperative course will be unremarkable.