In the category of area specific curettes a sub classification exists. The original Gracey series was developed in the 1930's by Dr. Clayton Gracey, a periodontist at the University of Michigan. They were designed to provide better access to root surfaces in deep pockets. They feature long shanks and unique blades, some with bends improving access to complex root surface morphology. The opposing ends of the double ended instruments have mirror image blades.
Gracey curettes are available in stainless steel or in carbon steel.
Carbon steel requires more care as it rusts very easily and also wears away more quickly. With the cone socket instrument, shank and blade can be unscrewed and replaced. Gracey's are also available in different combinations of metals, some stronger or more rigid than others. Another aspect in choosing an instrument is the thickness of the handle. Research has shown that a thicker handle is easier on our hands and wrists than a thinner instrument.