Comparing CBCT to model scanner for dental model scanning. An in vitro imaging accuracy study

Objective

The aim of this study is to compare the accuracy of cone beam computed tomography (CBCT) for dental model scanning to the accuracy of model scanners.

Methods

Subjects from private practice were collected and scanned according to specific selection criteria. A total of 10 STL files were produced and used as reference files. They were printed with a three-dimensional (3D) printer and then scanned with CBCT and model scanner. For trueness evaluation, all models were scanned once with both equipments. Each file derived from each scan was compared with the corresponding reference model file. For the precision measurements, the physical model from the first master reference model file was scanned 10 times with each equipment and compared with the reference STL file. A reverse engineering software was used for all 3D best-fit comparisons.

Results

With regard to the measurement of trueness of each method, the calculated mean root mean square (RMS) value was 0.06 ± 0.01 mm for the CBCT, and 0.15 ± 0.02 mm for the model scanner. There was a significant difference between the two methods (P < 0.01). For the evaluation of precision of each scanner, the mean RMS value was 0.0056 ± 0.001 mm for the CBCT, and 0.153 ± 0.002 mm for model scanner. There was a significant difference between the two methods (P < 0.01).

Conclusions

Cone Beam Computed Tomography seems to be an accurate method for scanning dental models. CBCT performs better than model scanners to scan dental models in terms of trueness and precision.