A method and apparatus related to forming prosthetic dental items or tooth restorations. A defective tooth, prosthetic dental item, or a dentition is scanned. A first electronic data set from a three-dimensional scan of a defective tooth, defective prosthetic dental item, or the dentition is generated, and one or more correspondence points or structure in the first electronic data set are assigned to one or more corresponding points or structures in a second electronic data set. The second electronic data set represents a tooth model. To generate a patient specific tooth model, the tooth model is adjusted such that a function which describes one or more distances between the one or more correspondence points or structures in the first electronic data set and the one or more corresponding points or structures in the second electronic data set is minimized.