Torque verification of different types of wrenches with the use of the own construction device.
Dr n. med. Piotr Stendera
Department of Prosthetic Dentistry, Medical University of Warsaw
Introduction
There is a common opinion that the torque wrenches become discalibrated because of the multiple use and the sterilization proces. Verification of the torque values indicated by the wrench is apparently impossible for the most of clinicians. And the implant system manufacturers mostly do not provide the service for control and callibration of the wrenches from their offer. Malfunctioning wrenches may cause inequality between the indication and the true torque and, consequently, generate many clinical problems. There are different types of the wrenches (rachets) available in the market. Most of them are based on the mechanical bending of the flexible arm indicating the torque on the appropriate scale. But there are also different devices that are breaking when achieving adjusted torque. Some of them are similar to the spring devices but some are similar to contra-angles.
Case Description
The paper presents the construction of the own device that allows for the torque verification of different types of the torque controllers. The principle of the measurement is based on the gravity (the arm of the wrench is situated horizontally and loaded with appropriate weight) and the value of torque is calulated acording to the popular equation for the torque (related to the weight and the arm).
Discussion
Some modifications of the method depending on the type of torque controllers and the results of the preliminary tests regarding the precision of their measurements (correlation between the indication and the true value of the torque) will be also presented.