Post Malone has silver teeth primarily because he wears silver-colored grillz as a style choice. These silver teeth are not permanent; they are removable dental accessories, often made from metals like silver or platinum, that cover his natural teeth temporarily. His natural teeth have undergone a major cosmetic transformation with porcelain veneers and diamond-studded teeth, but the silver look comes from these detachable grillz used for fashion and performance purposes, aligning with his personal expression and hip-hop culture influences.