A method of assessing the effectiveness of the friction fit interface by measuring reverse torque
Related Experiment Video
Updated: Apr 30, 2026

A Friction Testing-Bioreactor Device for Study of Synovial Joint Biomechanics, Mechanobiology, and Physical Regulation
Published on: June 2, 2022
Dimas João Rodrigues Neto1, Daiane Cerutti-Kopplin2, Accácio Lins do Valle3
1Professor, Department of Prosthodontics, Dental School, University of Southern Santa Catarina.
Statement Of The Problem:
The connection between abutments and implants is fundamental to successful prosthetic rehabilitation, and the loosening or fracture of the parts are undesirable outcomes.
Purpose:
The purpose of this study was to measure the reverse torque values of 2 different types of Morse taper implants.
Material And Methods:
Ten Morse taper implants were used, with their respective abutments. They were divided into 2 groups (n = 5): Group DH, implant interface with a double hexagon and Group OI, octagonal implant interface. Each abutment received 2 consecutive insertion torques (32 Ncm) at a 10-minute interval and 1 reverse torque after 5 minutes. The data were analyzed with the Student t test (α= .05).
Results:
The Student t test demonstrated no significant differences between the values of the insertion and removal torques of the 2 groups (Group DH, P= .22 and Group OI, P= .42) or the removal torque values of the groups (P= .12).
Conclusion:
The results suggest that the strength required to loosen the abutment screws as measured by reverse torque is similar for both a double hexagon interface (DH) and an octagonal interface (OI).
Related Concept Videos
Screw: Problem Solving
To evaluate the...
Frictional Forces on Screws
A jack with a square-threaded screw is a mechanical device used to lift heavy loads by applying a force at its handle. When the force is applied, the screw turns, raising the load. The screw can...
Net Torque Calculations
Torque
Torque can be considered as the rotational counterpart to force. Since forces change the translational...
Bearings: Problem Solving
Mechanical Efficiency of Real Machines
However, in reality, no machine can be truly ideal, and all of them experience some...

