Accuracy and reliability of linear measurements on digital models derived from CBCT and 3D laser scanned impressions

Abstract

Dental study models are essential records for orthodontic diagnosis, planning and treatment evaluations. As plaster models are prone to damage and loss, require storage space and inefficient to retrieve and transfer, digital models are been used to eliminate drawbacks of plaster model regarded as potential replacement of traditional plaster models. Aim: To compare the accuracy and reliability of linear measurements on digital models derived from Cone Beam Computed Tomography (CBCT) and three-dimensional (3D) laser scanned impressions with conventional plaster models. Objectives: i. To compare the accuracy and reliability of measurements made on Plaster and CBCT derived digital models. ii. To compare the accuracy and reliability of measurements made on plaster and 3- dimensional laser scanned impression models. iii. To compare the accuracy and reliability of measurements made on CBCT models and 3D laser scanned impression models. Materials and Methods: CBCT and plaster models will be prepared from 12 patients. Rubber base impressions will be scanned using 3D dental laser scanner. Landmarks will be marked and the linear measurements of all the three models will be compared using 3D software. Results: The derived data was subjected to ANOVA test, Post Hoc Tukey test, Intraclass correlation coefficients (ICCs) and Method Error to evaluate the reliability of repeated measurements. No significant difference was found between plaster models, CBCT models and impression scanned laser models. Conclusion: Plaster models, CBCT models and models obtained from laser scan of impressions are three different diagnostic records. Each have their own advantages and disadvantages. The present study shows that models obtained from laser scanned impressions are comparable to plaster models. The accuracy is adequate for initial diagnosis and treatment planning in clinical orthodontics Keywords: Digital models, Cone beam computed tomography, Laser scan, Meshlab, DIC