[Surgery]  what is the minimum ISQ reading that is acceptable for initial implant placement?

My inquiry pertains to both implants that we are not placing immed ant temp crowns on as well as on those that we are not placing temp crowns on?  I have read the ISQ info which states less than 60 is considered low stability but I would like to get a sense from your experience clinically what number do you feel good leaving the implant in place.  I also realize that torque of implant when placed is a factor as well.




by San Bhatha at Wed, Jul 16, 2014 1:46 PM

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Ho-Young Chung Replied at Thu, Jul 17, 2014 9:08 PM

If I don't get at least 30Ncm, I bury and wait 4 months and many cases I want a min of 35Ncm. As much as I would like to reduce number surgeries and complete the case as efficiently as possible, pushing the envelope can compromise our treatment for our patients. Period of healing will depend on each situation, each patient, etc. ISQ in my experience doesn't seem to correlate with initial torque value. Radiographic and clinical assessment along with ISQ all combine to help you decide whether implant is ready to be restored. hope that's as clear as mud. :) Ho-Young

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San Bhatha Replied at Thu, Jul 17, 2014 6:42 PM

Thanks for the great responses. When the initial torque is betw 20-35Ncm, and we decide to place a healing abutment, rather than bury and wait the 4mths with a healing screw, are we then just relying on the ISQ readings at future 6 week intervals as we do in our practice to determine when the implant is ready to be restored?

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Trevor Lake Replied at Thu, Jul 17, 2014 6:33 PM

Hi San, I may consider using an essix instead of a flipper, as it allows you to ensure that you are not putting pressure on the soft tissue during the healing phase. For the posterior, if torque is under 20Ncm then I would place a cover screw and bury it. If torque is between 20-35Ncm then you can place a healing abutment at the time of surgery.

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Mark Kwon Replied at Thu, Jul 17, 2014 6:28 PM

Low initial torque cases: Protocol for our practice. 1. Bury under tissue 2. Wait 4 month 3. Uncover and cheque ISQ >65 in all directions 4. Healing abutment 5. 2weeks impression

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San Bhatha Replied at Thu, Jul 17, 2014 2:14 PM

Thank you gentlemen for your responses. And thank you for confirming my protocol for trying to establish the 35 Ncm + torque and use of the ISQ. Let me ask you this, if 35 Ncm was not achieved for an ant implant that you were planning on placing a temp on, what would be your protocol? Would you have a flipper ready and place a healing screw on the implant ? And what about post implants where we are not placing any temps on, and your initial torque was under 35Ncm what are your protocols for handling these?

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Bernard Jin Replied at Thu, Jul 17, 2014 2:13 PM

Agreed. Using the ISQ as just one of your assessment tools is wise. To rely on the ISQ readings as the only tool for assessment is probably not wise. For immediate provisionalization - yes - rely on insertion torque as your gauge for go or no-go. I would not recommend using ISQ readings for this purpose.

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Glenn van As Replied at Thu, Jul 17, 2014 12:58 PM

Ho-Young I agree with your very well thought out post.... 1. Initial torque values of 35 NCm or higher are VITAL to immediates. 2. THe ISQ device really is vital to determining whether osseointegration is occurring in a standard way. 3. Tapping implants, patient symptoms , tissue swelling , suppuration or bleeding all are important as are radiographs in determining if an implant is ailing or failing. Glenn

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Ho-Young Chung Replied at Thu, Jul 17, 2014 5:53 AM

Hi San, As you are aware, ISQ at the time of surgery gives a baseline to compare to at subsequent ISQ readings (for example at 6-8 weeks or 4 months). In my practice, ISQ is just a tool although a very good tool. My immediate temporization protocol for single anterior implant is that I achieve primary stability of 35Ncm. Anything lower I would be very cautious about temporizing. So for me, initial torque is far more important than ISQ. On the other hand, for assessing osseointegration, ISQ is much more important (considering I won't do a reverse torque test unless I want to remove the implant intentionally). of course there are other factors involved in whether I can do an immediate temporization (such as patient compliance, occlusion, etc) and I don't solely rely on ISQ to assess osseointegration. hope that helps. Ho-Young