The dynamic natures of implant loading

Area of Science:

• Biomaterials Engineering
• Biomechanics
• Finite Element Analysis

Background:

• Understanding dynamic dental implant loading requires clarity on torque, force transformation, and stress distribution during assembly.
• Preload stress at interfaces significantly impacts implant performance before external loading.

Purpose of the Study:

• To create a detailed finite element model of a dental implant complex with spiral threads.
• To determine stress and strain patterns within the implant system and surrounding bone during assembly.
• To provide foundational data for studying dynamic loading of dental implants.

Main Methods:

• A finite element model of an implant, abutment, screw, and bone was created using HyperMesh.
• Assembly simulations were performed using ABAQUS and LS-DYNA with a 32-Ncm torque applied to the abutment screw.
• Regression analysis was used to correlate torque load with mechanical parameters.

Main Results:

• A 32-Ncm torque generated 554-N clamping force and 522-N preload, with screw elongation of 13.3 µm.
• Significant von Mises stress values were observed in the abutment screw and threads (up to 1365 MPa).
• Characteristic stress patterns (spiral, spring, bone holding) were identified within the implant complex.

Conclusions:

• Abutment screw elongation directly correlates with preload increase (47.9 N per 1.0 µm).
• Contact force at screw/bore interfaces is an ideal indicator of preload.
• Identified stress patterns provide insights into implant complex behavior during assembly.