# Passive Fit Evaluation of Implant Superstructures by Analyzing Accumulated Screw Tightening Torque: A Dental Technique

## TL;DR

This paper introduces a method to objectively evaluate the passive fit of dental implants by measuring screw tightening torque, offering a more reliable alternative to subjective tactile sensing.

## Contribution

The novelty lies in using accumulative screw tightening torque as a quantitative parameter for assessing passive fit in dental implant superstructures.

## Key findings

- Accumulative torques can help evaluate passive fit in dental implants.
- Time slopes of torque measurements may serve as useful indicators for fit evaluation.
- Further trials are needed to validate the method's effectiveness.

## Abstract

Achieving a stable passive fit is important in implant treatment, especially for restorations of screw-retained superstructures. A passive fit is often evaluated by tactile sensing of tightening a fixing screw; however, tactile sensing is a subjective procedure. Objective and quantitative assessment of passive fits can be performed by measuring the tightening torque on prosthetic screws. In this clinical case, accumulative screw tightening torques for passive fit and misfit superstructures were calculated to examine the usefulness of the proposed method. The results suggested that accumulative torques and time slopes of torques may be potentially useful parameters for quantitatively evaluating passive fits; further laboratory and/or clinical trials are necessary.