Accuracy of dental torque wrenches.

Area of Science:

• Dental Implantology
• Biomaterials Science
• Mechanical Engineering

Background:

• Accurate torque application is critical for the stability and success of screw-retained dental implants.
• Manual torque wrenches are commonly used in dental procedures, but their accuracy can be affected by usage and sterilization.

Purpose of the Study:

• To compare the actual torque output of new and used manual dental torque wrenches against their stated (target) torque values.
• To evaluate the accuracy of both spring-style and friction-style manual dental torque wrenches.

Main Methods:

• An in vitro study was conducted using calibrated torque gauges to measure the actual torque of new spring-style (Nobel Biocare) and friction-style (Zimmer Dental) wrenches, as well as used spring-style wrenches.
• Torque measurements were performed at target values of 15 N/cm and 35 N/cm.
• Statistical analysis was performed using a mixed-effects regression model with Bonferroni correction.

Main Results:

• At 15 N/cm, new spring wrenches (13.97 N/cm) differed significantly from used spring wrenches (14.94 N/cm), but not from new friction wrenches (14.10 N/cm).
• At 35 N/cm, new spring wrenches (35.29 N/cm) showed significant differences compared to both new friction wrenches (36.20 N/cm) and used spring wrenches (36.45 N/cm).

Conclusions:

• Discrepancies between actual and target torque values were observed in manual dental torque wrenches.
• These torque inaccuracies may compromise the clinical outcomes of screw-retained dental implants.
• Regular verification and calibration of manual dental torque wrenches are essential to maintain accuracy and ensure clinical success.