THE NUMERICAL MODELING OF FATIGUE PROPERTIES OF A BIO-COMPATIBLE DENTAL IMPLANT PRODUCED BY ELECTRON BEAM MELTING® (EBM)

摘要

Cyclic load could result in the fatigue failure of a component at stress levels below the yielding stress of material. Therefore, studying the mechanical behaviors of a dental implant structure under cyclic load is required. The numerical modeling of a cyclic load test was performed for a bio-compatible dental implant by using ANSYS® Workbench®. The fatigue test samples, made of Ti-6Al-4V were manufactured by Electron Beam Melting® (EBM) process. An abutment with octahedral lattice structure of 2 mm unit cell size was selected to design the abutment. A sinusoidal wave was used to apply the cyclic load, where the loading ratio was set at 10%. The influences of the loading force and the fatigue strength factor on the fatigue life of the octahedral lattice structure were numerically studied. According to the results, an increase in the loading force was associated with an increase in the maximum equivalent stress developed in the lattice structure. Also, the numerical results showed that applying a load above 441 N resulted in a sharp decrease in the fatigue life of the lattice structure from 10~7 cycles to 5.5×10~4 cycles. It was shown that an increase in the fatigue strength factor from 0.81 to 0.87 improved the fatigue life about 100 times. Therefore, improving the surface roughness of the bio-compatible dental implant could be one of the major factors that could increase the implant fatigue resistance and should be considered through the design optimization of the dental implant.