US Patent 7845942 Tooth preparation instrument and system of its use

A dental impression analyzer including a housing having two opposite open ends. A lower end of the two opposite ends fits over a tooth of a patient. A plurality of pins are slidably mounted in the housing. The pins are of equal length, extending parallel to each other, and at least a portion of sidewalls of the housing extending parallel to each other and parallel to the plurality of pins to maintain the pins parallel to each other and to guide movement of the pins. The plurality of pins are tightly compressed together in an interior of the housing. A lower end of the pins are positioned to engage an uppermost surface of the tooth of the patient when the housing is fitted over the tooth of the patient. An upper end of the pins replicates the uppermost surface of the tooth when the lower end of the pins engage the uppermost surface of the tooth.