Validity and reliability of digital models generated from CBCT scanning

Abstract

INTRODUCTION:Dental study models are essential for implant treatment planning, for fixed and removable prosthesis and for orthodontic diagnosis, treatment planning, and follow up. Digital dental workflow has invaded modern dental treatment and digital modelling has prompted ongoing research. Digital or virtual models could be generated by various techniques. OBJECTIVE: To evaluate the validity and reliability of three-dimensional (3D) digital or virtual models produced using CBCT scanning of dental impressions or casts.:Methodology: Two techniques were used to obtain 3D virtual model files including scanning of impressions by CBCT machine besides scanning of the corresponding casts by the same CBCT machine (N=36). Four linear measures (canine to molar, inter-canine, inter-molar and vertical dimensions) were measured in all virtual models and compared with the caliper measurements of the stone model. Additionally, Stereolithography (STL) files from the two techniques were registered with that obtained from a desktop scanner by using a best-fit matching in a three-dimensional modeling program. This program measured the mean differences between the virtual meshes and qualitative assessment was performed through the obtained color maps. RESULTS: Some linear measures and the 3D deviation analysis revealed statistically significant differences but all were considered clinically accepted. Virtual models created by CBCT scanning of casts exhibited less differences ranging from (0.17/ -0.02 mm), whereas CBCT scan of impressions revealed mean discrepancies with a range (0.16/ -0.04 mm). CONCLUSION: CBCT scanning of the impressions and stone casts provided acceptable results but with granular surface of the model. Both methods could be used in clinical setting provided that highly accurate devices are used.

Comparative study of reliability in three software meshmixer, 3d slicer and nemocast of the intercanine and intermolar spaces of digital models

“…The study carried out by Noha et al that analyzes the validity and reliability of the digital models generated from the CBCT scanner found that the measurements provided by Autodesk Meshmixer were reliable as in our study (9).…”