Abstract: A dental bur includes a shank adapted to be held by a dental drill and an abrasive portion. The lowermost abrasive portion at the free end of the bur is of a different color from the remaining abrasive portion. As a result, a dentist can observe the colored section to determine the depth of the bur tip under the gum line. Preferably, the bur is formed by coloring the corresponding section of the substrate from which the bur is made and then coating the entire working surface of the bur (colored and uncolored) with diamond chips.