A benchmark for accuracy evaluation of dental crowns up-to-date manufacturing

In recent years, digitizing and automation have gained an important role in manufacturing of dental devices. Instead of the traditional plaster model procedure, scanning techniques may be used for the geometry acquisition. Point clouds are processed and converted into standard CAD models, from which metal tooth cap can be fabricated by milling, integrating CAM tool, or by rapid manufacturing (RM) techniques. Good quality control is critical to ensure the crown fit: an improper fit could cause crown falling off. So far there is no standard procedure for evaluating quality of both 3D digitization and milling/RM cap making processes. Thus, a specific benchmark is designed to represent critical features of a stone replica, like a dental arch with studs resembling teeth prepared for crowns installation. The benchmark is then produced and measured by means of a coordinate measuring machine.