A method of assessing the effectiveness of the friction fit interface by measuring reverse torque.

The Journal of prosthetic dentistry

PubMedID: 24767898

Rodrigues Neto DJ, Cerutti-Kopplin D, do Valle AL, Pereira JR. A method of assessing the effectiveness of the friction fit interface by measuring reverse torque. J Prosthet Dent. 2014;.
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 with a significance of 5%.

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).