Topological optimization has sparked significant interest in developing various mechanical elements that achieve functional designs while maintaining structural integrity and reducing mass. However, the resulting elements often feature complex geometries that are challenging to manufacture using traditional methods. Additive manufacturing with both metals and polymers has facilitated the production of these intricate models. Utilizing the reticular structure method in topological optimization significantly reduces the mass of mechanical elements. This reduction also alters the dynamic behavior of the element, modifying its natural frequencies and mode shapes. This paper presents a study on the dynamic behavior of gears manufactured from various plastics using 3D printing via fused deposition modeling. The research employs both numerical and experimental methods. Depending on the type of plastic used, the mass of the spur gears was reduced by 25 to 28% based on the lattice optimization. This mass reduction led to a decrease in the natural frequencies of the gears by 31% to 44%. These changes in frequency significantly affect the dynamic response of the elements. This was verified through experiments conducted on a test bench.