Accuracy of triangular meshes of stone models created from DICOM cone beam CT data

Dimitrios Apostolakis,Georgios Michelinakis,Georgios Kourakis,Emmanuel Pavlakis

doi:10.1186/s40729-019-0171-9

Abstract

BackgroundThe aim of this study was to assess the theory that CBCT scanners can be used for a subsequent triangular mesh generation which accurately represents the actual stone model.Ten, recently acquired stone models, were used in the present study. The stone models were initially scanned with the Dental Wings 7Series dental scanner. Each stone model was then scanned using a 150-μm voxel resolution in a Planmeca Mid CBCT device with 2 sets of exposure parameters and in a Newtom VG device. The DICOM files were initially imported in Blue Sky Plan implant surgery software, segmented and then imported for computational manipulation in CloudCompare, a dedicated mesh handling software.ResultsFor all CBCTs and for all exposure parameters, the mean (SD) difference was 0.052 (0.011) mm ranging from 0.032 to 0.070 mm with a 95% CI for the population mean of 0.052 ± 0.004 mm. Specifically, the mean (SD) difference for each device/exposure parameter tested was (1) Newtom VG = 0.040 (0.006) mm, (2) Planmeca Mid 90 = 0.057 (0.0066) mm, and (3) Planmeca Mid 80 = 0.059 (0.0063) mm.ConclusionsThere are differences amongst the CBCT models, whilst different exposure parameters of the same model do not seem to offer a significant advantage. The interaction between the threshold value and the imaging modality as far as the errors are concerned necessitates the careful selection of the right threshold value for the triangular mesh creation.

Highlights

The aim of this study was to assess the theory that Cone beam computed tomography (CBCT) scanners can be used for a subsequent triangular mesh generation which accurately represents the actual stone model
The need for digital dental models is rising along with the increased usage of computer-aided designed and computer-aided manufactured (CAD/Computer-aided manufacturing (CAM)) implant surgical guides, orthodontic clear aligners, the practice of 3D orthognathic surgery including the applications of the so-called virtual patient, and as a space-effective mean of model storage [1,2,3,4,5,6,7]
In view of the increased costs related to the acquisition of a highly accurate desktop scanning device and the fact that CBCT devices are becoming increasingly common either in dental practices or in specialised dental radiological facilities, it is our theory that these CBCT scanners can be used for a subsequent triangular mesh generation that accurately represents the actual stone model

Summary

Introduction

The aim of this study was to assess the theory that CBCT scanners can be used for a subsequent triangular mesh generation which accurately represents the actual stone model. Scanning the stone model with either a 3D laser or a white light desktop scanner remains the gold standard for the digitisation procedure since this technique is widely accepted as being the best available method [8, 9]. In view of the increased costs related to the acquisition of a highly accurate desktop scanning device and the fact that CBCT devices are becoming increasingly common either in dental practices or in specialised dental radiological facilities, it is our theory that these CBCT scanners can be used for a subsequent triangular mesh generation that accurately represents the actual stone model. The expected effect size (differences between the two modalities, CBCT and desktop scanner) should not prohibit the effective usage of this mesh model in certain clinical situations

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Conclusion