A methodology for determining precision and accuracy of the measurement of position and orientation of implant interfaces for multi-implant structures.

Abstract

The digital workflow relies on many technologies such as intra-oral scanners, CBCT, guided surgery, robotics, and photogrammetry. Efficient and uniform testing methods are required for assessing the precision and accuracy of these systems to select the right technology for the right task. The method uses values that are directly derived from the measurement of the implant position and orientation in the scanning software, photogrammetry software, and/or the CAD software. It was developed over a decade ago for desktop scanners and successfully used for photogrammetry, intra-oral scanners, and CBCT. The components which can be evaluated are the positional precision and accuracy in the implant plane, in the implant axis, and the direction/angle of the implant axis. The methodology can also be used to assess the impact of errors in the implant axis on the fit of the structure. Many other values such as cross arch distances can be computed. Applying this methodology to several devices brought to light the huge differences in their behavior. This has a major impact on how the devices need to be tested. The precision both in vitro and in vivo can be determined easily. This led to important conclusions relating to the validity of in vitro tests. The methodology is providing an efficient and uniform method for the analysis of the precision and accuracy of multi-implant structures. It has brought to light the strengths and weaknesses of different technologies not known before.