Comparison between Stresses Induced on the Dental Implant Retaining Screw before and after Tightening
Author(s): Mohamed Tharwat Hamed* and Hisham Abdullah Mously
The untightening resistance has a negative impact on the stability of implant-abutment system. However, there is a need to retighten the screws periodically.
Aim: This study aims to compare the stress level on the dental implants before and after tightening of the screw. Methods: A 3D geometrical idealization was constructed in place of a missing mandible first molar of an adult. An integrated retaining screw was fixed to a standard Ti-6Al-4V abutment after osseointegration. Model’s geometry was exported to generate threedimensional mesh.
Results: The results were acquired with 14 values of the friction coefficient for type III gold and Ti-6Al-4V titanium alloy screws. There was variation in values of gold screw before tightening; however, it was considerably low as compared to the corresponding values in the case of titanium screw. Moreover, the magnitudes of Pa of gold screw were less as compared to the titanium screw. There is a decrease in stresses at maximum tightening moment because of increase in coefficient of friction for assembling different parts. Moreover, the magnitudes of Pa of gold screw were less as compared to the titanium screw.
Conclusion: The invariable decrease in the release of wrench tightening moment was due to the increase on the wrench tightening moment. Moreover, the decrease in the stresses at maximum tightening moment applied to screw was because of increase in coefficient of friction for assembling different parts.