ISQ as a guide for implant rehabilitations

Dr Trasarti shares his protocol and clinical insights

Long-term success in implant therapy is an aim that all clinicians strive for. Fundamental to this is proper implant placement, surgical site preparation, and good osseointegration after insertion. Although a torque value is a basic prerequisite for primary stability, it alone does not provide complete information for the clinician. The insertion torque is a very important parameter. We know that low or high torque is counterproductive to implant osseointegration, so we always hope to achieve torque values between 25 and 45 Ncm. Unfortunately, although this parameter is important, it remains a measurement only in the surgical procedure and does not allow us, like the ISQ value, to have an objective non-surgeon dependent value.

Importance of ISQ values

Therefore, knowledge of ISQ values is fundamental to assess both primary implant stability (mechanical stability) and secondary implant stability (biological stability or osseointegration). That knowledge can directly influence the timing of prosthetic rehabilitation and improve the confidence of clinicians, regardless of their experience level. It is a simple, easily transportable and completely non-invasive diagnostic tool that provides precise information needed to make well-founded decisions and for the success of an implant surgical treatment.

Function of the ISQ device

More specifically, the ISQ device is transmitting magnetic pulses to make a so called SmartPeg to vibrate. The SmartPeg is attached to the implant prosthetic connection. The resonance frequency of the SmartPeg is measured by the ISQ device to determine the ISQ value (Implant Stability Quotient, ranging between 0 and 99.) This is a lateral stability test that measures implant-bone interface stiffness. The higher the resonance frequency, the higher the ISQ is.

Protocol for using Osstell

Although Osstell is well known, I’ve published a specific protocol* on how to use it. There has been much confusion among clinicians about the timing of measuring; some prefer to use it before prosthetic loading, others at the time of implant placement, and still others only when in doubt. I started using it in various clinical situations, from implant placement without bone augmentation up to cases requiring regeneration. What I discovered, following the same implant preparation, is that in patients of the same age and receiving the same surgical treatment, the timing of a good osseointegration could still vary. For some patients I could accelerate rehabilitation, for others it was necessary to wait.

Clinical applications and findings

For example, you might consider a sinus lift with 2–3 mm of residual bone and believe you know the correct timing for loading the implant. Other situations may involve post-extraction implants or cases requiring bone augmentation.My protocol is to offer the clinician safer rehabilitation in all clinical circumstances that we face. This could for example be in simple cases, in post-extractive or bone regeneration cases to know precisely both the implant stability at the time of insertion and the secondary stability resulting from osseointegration.

Following the same surgical approach in the same anatomical site, or in the same bone regeneration, the osseointegration may vary from patient to patient. The aim is to define an individualized protocol that can either safely shorten rehabilitation time, if possible, or delay the treatment to ensure good regeneration around the implant, thereby avoiding complications.

Factors influencing ISQ values

Of course, the correct preparation of the surgical site is critical, but there are many clinical and systemic parameters of the patient that influence the ISQ value, such as implant location, diameter and length, insertion torque, macro-design, bone quality at the site of placement, a grafted or natural bone site, vascularisation of the bone influenced by systemic or clinical conditions, and the presence of pathology.

Too many parameters that are for both novices and experts impossible to control at the same time. In this regard, the Osstell Beacon proves to be an invaluable tool in the hands of the surgeon.

In addition to the fundamental clinical benefit, there is to be noted the benefit of accurate registration and documentation that is valid from both a legal and statistical point of view. By documenting the patient's data in a software offered by Osstell, I can thus exchange information with my colleagues and also other collaborators to modify and define the correct individual rehabilitation protocol for this patient as well as to improve our surgical protocol.

Conclusion

The real clinical problem solved by this protocol, is that we need to assess the degree of osseointegration and implant stability before the prosthetic phase not only at implant placement but throughout the entire implant therapeutic course.

In conclusion, this tool proves to be applicable in all clinical conditions that may arise. In my experience, I use it in cases of post-extraction implants, in cases of native bone implants without regenerative procedures or in sinus lift procedures, and of course in cases of bone regeneration to track the osseointegration and stability of the result over time.

Reference

1. *Trasarti S., Toti P. et al. Specific use of the implant stability quotient as a guide to improve healing for patients who had undergone rehabilitation with fixed implant-supported dental prostheses J Stomatol Oral Maxillofac Surg. 2023 Oct;124(5):101528. https://pubmed.ncbi.nlm.nih.gov/37301374/
2. Corresponding to:
   STEFANO TRASARTI
   info@implantologiavanzata.com
   www.implantologiavanzata.com
   www.marienklinik.it