Design and Fabrication of Inner Konus Crown Using Three Dimensional Computer Graphics / 대한치과보철학회지

ABSTRACT

A fabrication method of inner and outer crown using CAD/CAM is presented. The information of abutment teeth is transferred to a computer through a 3-dimensional scanner. A Konus inner and outer crown is designed on a computer and a real crown is machined based on this design using CAM. This method can save laboratory time and reduce inaccuracies compare to conventional casting procedure. A stone model with six prepared abutment teeth from a patient was used in this study. Three dimensional information from the model was transferred to a computer using a contact type 3dimensional scanner with a 25micrometer accuracy. All margins were identified on a computer image where there is a change in surface taper of a model. To provide a cement space, the image of a inner surface of a Konus inner crown was duplicated 25micrometer apart from the surface of a prepared abutment teeth image. The cement space was 20micrometer at the cervical margin. All Konus crowns were machined with a 10micrometer accuracy. It was concluded that this method can reduce working-time for the laboratory process and increase accuracy. A further research is required to make a simplified process for a more complex prosthesis.