Comparative analysis of miniplate design and metal magnesium screw ECAP against titanium

Abstract

In the internal fixation management of maxillofacial fractures, placement of miniplates and screws is necessary until bone repair occurs. Magnesium has the potential for use as a miniplate and screw for the jaws due to its biocompatibility and biodegradability, so that reoperation to remove the miniplate and screw is not necessary. The equal channel angular pressing (ECAP) process is a method to control the corrosion rate of magnesium and increase the mechanical properties. When constructing the miniplate and screw design from ECAP magnesium, referring to the safety factor of the titanium design that already is being used, adjustments must be made according to the characteristics of magnesium so that damage can be avoided. We compared the characteristics of the magnesium ECAP miniplate and screw design against those of titanium. For this study, we used the finite element method, which consists of a displacement formula to calculate component movement, strain, and pressure under internal and external load. Afterwards, the magnesium ECAP miniplate and screw design was subjected to a loading simulation that was analyzed according to the von Mises theory. After stress simulation testing, the magnesium ECAP miniplate and screw, which was expected to be used in the management of maxillofacial fractures, was engineered to reduce the stress received. The design was divided into two types: In type 1, the number of screws was increased to eight, and the total weight of the miniplate and screw was 118.212 mg. In type 2, the diameter of the screw heads was made larger than their original shape so that the total weight was 169.414 mg. The type 1 alternative design of the magnesium ECAP miniplate and screw could be more effective in the management of maxillofacial fracture.