Evaluation of Implant Abutment Screw Torqueing Protocols on Reverse Torque Values: An In-vitro Study

INTRODUCTION

 

  Dental implant survival and success depends on many factors. Most common prosthetic complications occur due to implant abutment screw loosening.1 This prosthetic complication may lead to abutment/crown mobility resulting in screw fracture or even bacterial leakage.1,2 Screw loosening can be caused by multiple factors such as inadequate torque3, poorly machined components, excessive loading, screw and restoration design.4,5

 

  The screw is primarily subjected to 2 different types of forces; the first one being the force working on separating the parts, called joint separating force, and the other is the force keeping the components together, called clamping force.4

  

  Implant manufacturers provide no guidance on tightening protocols in the instructions for use. There are few published protocols in the literature, some that recommend tightening the screw and waiting 10 minutes before tightening again.6,7 The null hypothesis for the study is, there would be no significant difference in torqueing protocol with regards to the reverse torque value (RTV).