US Patent 7004757 Tooth preparation instrument and system of its use

At an initial office visit, the dentist makes an impression of the portion of the mouth in which the tooth is located, with upper and lower occlusal surfaces at or below the gum line. After preparation of a crown, the dentist presses the surface contour tool against the biting surface of the tooth to determine the depth settings for at least one burr in a surface tool that will remove the upper surface of the tooth and create a working surface for the material removal device. The dentist inserts at least one burr with the proper length in this tool so that when the tool is lowered onto the tooth, a flat surface will be created. The flat surface tool and the center hole drilling burr are operated with a device that locks onto the tooth and ensures that the top surface of the tooth will be perpendicular to the central longitudinal axis of the tooth. The dentist inserts the guide pin of the material removal device in the center hole or onto a disk post and begins to remove material from the side of the tooth.