Evaluation of a contemporary CAD/CAM system.

The objective of this study is to investigate the accuracy of the TracerCAD system in measuring a model of known dimensions and volumes. A cylindrical nylon 6.6 model was prepared. Landmarks were added to indicate proximal, distal, anterior, medial, and lateral. Four additional landmarks were added at regular intervals along the length of the cylinder with a view to calculating diameters and volumes relative to these landmarks. The model was measured using a comparator with a guaranteed accuracy of 0.01 mm and was traced using the TracerCAD system (Test 1). The test was repeated with the model rotated by 90 degrees (Test 2), to determine whether there were any effects related to the orientation of the model in relation to the transmitter. The difference in average volume between measured results and TracerCAD scans was between 0.20% and -1.96%. Individual trace volumes varied between -0.0085% and -4.50%. In all volumes measured in Tests 1 and 2, all maximum volume percentage differences measured greater than 3%.