Osseointegration and the ISQ-scale

Once attached to an implant, magnetic pulses cause the MulTipeg™ to vibrate. The instrument measures the frequency of the vibration and translates it to 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, which correlates with implant displacement, i.e. micro-mobility. The local bone density determines the ISQ value, and is influenced by factors such as the implant placement technique, implant design and healing time. Implants with low and/or dropping ISQ values seem to pose an increased risk for failure compared with implants with high and/or increasing values.

 

The ISQ-scale, 1-99 ISQ

Values above ISQ 70 indicate a very stable implant with low micro-mobility. This value is typically recommended for one-stage and immediate loading. A second measurement is recommended before the final restoration to verify osseointegration.

It appears that ISQ values above 70 can withstand normal forces in the mouth.

Osseointegration

Studies indicates that values in the range of 75 ISQ means the implant is already so stable that osseointegration cannot add stability in a significant way. The proof of osseointegration is the lack of a drop in ISQ.

If the implant has a low initial ISQ, let’s say 55, osseointegration can add stability over time.

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

  • Trisi P, Carlesi T, Colagiovanni M, Perfetti G, 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., J Oral Rehabil ; 2013-Mar ; 40(3):221-7

In addition, the importance of a primary and secondary ISQ measurement to detect an increase of stability and hence sufficient osseointegration, is shown in the following selection of articles;

  • Barewal RM, Oates TW, Meredith N, Cochran DL., Int J Oral Maxillofac Implants 2003: 18: 641–651
  • Glauser R, Lundgren AK, Gottlow J, Sennerby L, Portmann M, Ruhstaller P, Hämmerle CH., Clin Implant Dent Relat Res 2003: 5: 47–56.
  • Bogaerde LV, Pedretti G, Sennerby L, Meredith N., Clin Implant Dent Relat Res. 2010;12 (Suppl 1):e83-94.

Primary and secondary measurements are equally important in order to detect a decrease in stability, to identify potential implant failures which has been demonstrated in several articles, e.g.;

  • Glauser R, Sennerby L, Meredith N, Re´e A, Lundgren A, Gottlow J, Hämmerle CH., Oral implants Res 2004: 15: 428–434
  • Turkyilmaz I, McGlumphy EA.,BMC Oral Health. 2008;8:32.
  • Östman PO, Hellman M, Sennerby L., Int J Oral Maxillofac Implants. 2008;23:315-22.
  • Vanden Bogaerde L, Rangert B, Wendelhag I., Clin Implant Dent Relat Res 2005: 7(suppl. 1): 121– 130.