Osseointegration and The ISQ Scale

When attached to an implant, the MulTipegTM is forced to vibrate by exciting it with magnetic pulses. The frequency of the vibration is picked up by the instrument and translated into an ISQ scale value between 1 and 99. The higher the ISQ value, the better the stability.

RFA measures implant stability as a function of interface stiffness and correlates with implant displacement, i.e. micro-mobility. The ISQ value is determined by the local bone density and is influenced by for instance implant placement technique, implant design and healing time. It seems like implants with low and/or falling ISQ values pose an increased risk for failure compared with implants with high and/or increasing values.

If the ISQ is low at insertion, osseointegration will add stability, which can be seen as an increasing ISQ value.

If the ISQ is high, typically 75 ISQ or above, osseointegration cannot add stability in a significant way since the implant is already stable. If osseointegration does not take place, the ISQ value will decrease.

The ISQ value correlates also to implant micro mobility, as shown in the articles below

Trisi P, Carlesi T, Colagiovanni M, Perfetti G

Implant Stability Quotient (ISQ) vs direct in-vitro measurement of primary stability (micro motion): effect of bone density and insertion torque

J Osteol Biomat 2010; 1:141-151 | ID:-354 |

Pagliani L (L) ; Sennerby L (L) ; Petersson A (A) ; Verrocchi D (D) ; Volpe S (S) ; et al.

The relationship between resonance frequency analysis (RFA) and lateral displacement of dental implants: an in vitro study.

J Oral Rehabil ; 2013-Mar ; 40(3):221-7