Related Experiment Video
Updated: Jan 17, 2026
An Improved Mechanical Testing Method to Assess Bone-implant Anchorage
Published on: February 10, 2014
The Insertion Torque-Depth Curve Integral and Implant Micromotion: A Study on Polyurethane Foam Blocks
Purpose:
To investigate the relationship between the implant micromovements and the torque-depth integral (I) or insertion torque (IT) to test a new reliable primary stability measurement parameter.
Materials And Methods:
Cylindrical and tapered-cylindrical implants were placed into monolithic polyurethane foam blocks (Sawbones), featuring three different densities (0.24, 0.32, and 0.48 g/cm3). After both types of implants were placed under three different site preparations (standard, undersized, and oversized), the (I) and the IT were measured via a torque-measuring micromotor. Micromotion was measured by applying a lateral load to abutments mounted on implants and then recording displacement through a tensile testing machine. The relationship between micromotion and (I) [(I)-micromotion] as well as the relationship between micromotion and IT (IT-micromotion) were studied via regression analyses.
Results:
Significant inverse nonlinear relationships (P < .001) were observed between (I) and micromotion, as well as IT and micromotion, across all implant designs and preparation protocols (according to a negative-power equation). No statistically significant differences were found between the slopes of (I)-micromotion and IT-micromotion curves.
Conclusions:
Results of the present study provided additional evidence that the torque depth (I) is a reliable primary stability measurement parameter. However, tests should be repeated on materials more similar to bone, and axial loads should be applied instead of lateral loads to implants.
