Correct measurement of implant stability

Knowing when it’s time for know-how

The correct measurement of implant stability and osseointegration has always been a fundamental criterion for the success of the treatment. The explicit patient demand for streamlined treatment processes combined with an increasing number of patients with risk factors result in progressive and ambitious protocols in which conventional processes such as the torque or percussion test are being strained to their limits.

pip* spoke to Professor Dr Daniel Buser, Director of the Oral Surgery and Stomatology Clinic at the University of Berne Dental Hospital, about the options for reliable diagnostics available on the market today.

Let’s be serious: As an experienced dentist, I can tell during insertion whether my implant is stable or not, right? And if I can’t, I probably shouldn’t be implanting it in the first place...?

Prof. Buser: I think if that were the case then you should be able to expect me to have mastered the technique too – I have been treating an average of 150 patients a year for more than 30 years. As the appeal of implant treatment grows, we are now striving both in these patients’ best interests and in the interest of our own efficiency for increasingly shorter integration times and prosthetic treatment protocols. At the same time, the stability of the implant shouldn’t just be a matter of instinct – it should be possible to measure it objectively.

How does the RFA method work and what does the ISQ value actually indicate?

Prof. Buser: The ISQ – Implant Stability Quotient – is measured using the Osstell probe and a SmartPeg screwed into the implant. The ISQ is the unit of measurement for the resonance frequency analysis (RFA) used to assess the stability of an implant. This resonance frequency is measured on a clinically applicable scale from 1 to 100 ISQ. Below 60 ISQ you are in the critical zone and as of 70 ISQ you are entering the desired high stability zone.

Every practice has a device collecting dust in a corner which was once proclaimed as the next big thing, but was in fact never really employed in actual practice...

Prof. Buser: That is indeed true and could be down to the fact that the novelty gadget aspect of some devices makes them particularly attractive to practitioners. However, in the case of Osstell ISQ, its usage is quantifiable immediately on the basis of considerably shorter integration times and thus a clear benefit for your patients and your own treatment times and protocols. The benefit is so practical and immediate that, like us, you’ll never want to put it down. We have been experimenting with the RFA method since 2001.

However, the first and second generations were anything but reliable and not particularly user-friendly. The third generation brought with it a whole host of improvements, and we have been using the device in our clinic continuously since 2009. Since then, we have been able to offer our patients notably quicker prosthetic treatment, also in part due to our preference for the hydrophilic SLActive implant surface: Standard implantations generally take four weeks or eight weeks with GBR or sinus floor elevation (SFE), assuming an ISQ value of ≥70 during the final check. If the critical value isn’t attained, we simply wait. The option of longitudinal application is a particularly great advantage.

Very important: These noticeable time savings do not by any means go hand in hand with a compromise on safety. On the contrary – the Osstell ISQ measurement allows us to be sure that we only subject really well osseointegrated implants to prosthetic loading. A recently published study with 109 implants with simultaneous SFE by Kuchler et al., COIR 2017, confirmed this conclusively. You’ll be amazed how many of your patients you can treat considerably faster without suffering any sleepless nights. By the way, the method has already been around for more than 20 years and is extensively documented scientifically and academically in over 200 studies – as such, we are also well beyond the high-tech novelty gadget phase.

In conclusion, what do you see as the greatest advantage for day-to-day use?

Prof. Buser: Looking back over all the clinical experience from the last eight years, I can say with great satisfaction that today with the RFA method we are able to use a technology that provides us with reliable and objective information on whether an implant is sufficiently well integrated in bone or not. The critical value of 70 ISQ we have chosen has also proven itself time and time again. As such, we enjoy a good sense of security and can provide around 80% of patients with prosthetic treatments much earlier than was possible even 10 years ago. Our treatment concepts are also considerably more appealing to patients as it is possible to shorten the phase with a temporary, mostly removable denture considerably for most patients.

Thank you for sparing the time to speak to us today, Professor Buser!

*Source: First published in pip 5/2017