Dental Burs used in conjunction with a dental handpiece, cuts away hard tissue. Dental burs come in a wide variety, each one offering specific advantages that function best in certain situations. Burs are generally known as either a carbide bur or a diamond bur. Each type of bur comes in varying degrees of sharpness, lengths, shapes and sizes. Dental diamond burs are most often used to grind away tooth tissue, usually enamel. The grinding motion of a diamond bur leaves a rough surface. They are needed when a cut requires extreme precision. Carbide burs are most often used when preparing cavities for fillings, shaping bone and removing old fillings. Carbide burs cut and chip away the tooth structure. They leave a smoother surface than a diamond bur.