Torque wrench anyone?

I get this question a lot?   Whats a torque wrench?

At the time of surgery, the clinical stability of an implant is tested and assessed based on insertional torque measurements….this is the amount of force that is taking to place the implant into the jawbone.  We measure this with all implants, at the time of placement with a torque-wrench, (as seen above) and right before the dentist restores or “loads” the implant with a crown.  The purpose for doing this is to make sure that the bone cells have engaged or adhered or “osseointegrated” the implant.  Torque numbers between 30-40Nm at the time of placement are typically a number we shoot for.  This is usually indicative that sufficient stability of the implant  has been achieved, increasing the likelihood of the implant osseointegrating.  On a microscopic level, the is really measure the amount of space, or gap or lack there of, between the implant surface and the hold that is drilled into the bone.  The “tighter” the fit, the higher the torque number.  However on the flip side…..

For years there was some thought that high torque numbers (over 45Nm) at the time of placement of dental implants could actually be detrimental and lead to implant failure and none-osseointegration!  This was thought to be due to “marginal bone resorption” around the implant.  Although this concept was widely accepted in the literature years ago there is new research that showing that actually high torque numbers at the time of placement show a higher clinical success rates.

In the most recent edition of the JOMI journal (International Journal of Oral & Maxillofacial Implants), they perform a meta-analysis of 154 articles (11 from Ovid, 112 from PubMed, and 31 from EBSCO) to evaluate correlations between marginal bone resorption and high insertion torque value (> 50 Ncm) of dental implants.

Conclusion:  No need to worry about high insertion torque and marginal bone loss.   This study revealed there was no statistically significant differences between high insertion torque of >50Nm and conventional insertion torque in terms of effects on marginal bone resorption.

Int J Oral Maxillofac Implants 2015;30:767–772. doi: 10.11607/jomi.3884