Various tools are used with a dental surveyor, including analyzing rods, carbon markers, undercut gauges, and protective sheaths for a specific function. A carbon marker is a parallel-sided carbon rod used to mark the survey line on a cast or a crown on a cast. The carbon marker (with or without protective sheath) cannot differentiate more than one survey line on the cast if needed. The wear of the carbon marker along the parallel walls after repeated use may give an incorrect survey line. We suggest a simple modification in the analyzing rod to prepare a two-colored surveying tool. An analyzing rod is a parallel-sided rod used to analyze the relative parallelism of two or more surfaces of a cast and to mark survey lines on wax patterns. With the modified analyzing rod, the survey lines can be marked with two colors, and the problem of breaking of the carbon marker also can be eliminated.
Carbon Color