Comparison of the accuracy of a 3-dimensional virtual method and the conventional method for transferring the maxillary cast to a virtual articulator.

STATEMENT OF PROBLEM: The currently available virtual articulators fail to locate the digitized maxillary cast at the exact position in the virtual environment. Some locate the casts on a mechanical articulator with a facebow, and this position is then digitized for the virtual environment. PURPOSE: The purpose of this study was to compare the location of the maxillary cast on an articulator by using 2 different procedures: the conventional method and a virtual method. MATERIAL AND METHODS: With the conventional procedure, the kinematic axis of the participant was determined with an axiograph. The location of the maxillary cast in reference to this axis was then physically transferred to a Panadent mechanical articulator. By a virtual procedure, the same kinematic axis and the maxillary cast were transferred directly from the participant to the Panadent virtual articulator by means of reverse engineering devices. The locations obtained with both procedures were compared in a virtual environment with an optical scanner. By calculating the deviation at every point of the occlusal surface, the results obtained with this procedure were then compared with those of the conventional method. RESULTS: The mean deviation on the occlusal surface was 0.752 mm, and the standard deviation was 0.456 mm. CONCLUSIONS: The deviation between the procedures was sufficiently small to allow the methodology for orthodontic purposes. However, the accuracy of the virtual procedure should be improved so as to extend its use to other fields, such as orthognathic surgery or dental restorations, in which the clinical technique requires an articulator.

Direct transfer of the position of digitized casts to a virtual articulator.

This article describes a digital technique to transfer the location of digitized casts obtained directly from the patient to a virtual articulator (digital/virtual facebow transfer). The primary advantage of this technique is that it allows the dentist and the dental laboratory technician to work in a fully digital environment without having to mount stone casts on a physical articulator. This results in a significant time reduction and a higher degree of accuracy in the cast location.

Improving the digital workflow: direct transfer from patient to virtual articulator.

When designing a custom-made dental restoration, using a digital workflow represents an important advance over mechanical tools such as facebows or mechanical articulators. When using virtual scanning procedures, there is a direct transfer from the patient to the articulator. This paper presents a novel methodology to design custom-made restorations. This new approach permits the transfer of all data directly from the patient to the virtual articulator, always taking into account the kinematics of the mandible. Rapid further developments can be expected in the near future.