Dental burs are used for cutting hard tissues - tooth or bone. They are made of steel, stainless steel, tungsten carbide and diamond grit.
Diamond burs are most commonly used for cutting through porcelain, and carbide burs are best for preparing cavities for fillings, shaping bone and removing old fillings.
Diamond is the hardest material available and is used to grind away tooth tissue, usually enamel. The grinding motion of a diamond bur leaves a rough finish.
Diamond burs come in an array of shapes and are available in a range of grits; from ultra fine to super coarse. When cutting away porcelain restorative material diamond burs are very effective.