Analysis of the effects of mesh reduction of digital files on the surface area and volume accuracy of complete dentures using an intraoral scanner.

Background: The purpose of this study was to determine the accuracy of an intraoral scanner to digitally duplicate complete dentures and analyze the effects of mesh reduction of digital files on the surface area and volume accuracy of complete dentures, in vitro.

Methods: A mandibular complete denture was scanned by a desktop scanner to create a digital STL reference file (control). Fifteen identical scans were created by using an intraoral scanner and exported as STL files (test group). These 15 files were saved at 100% of the original scan resolution then reduced to 75%, 50%, 25%, and 10% of their original quality. These 75 scans were statistically analyzed by calculating The Hausdorff Distance (HD) and Dice Similarity Coefficients (DSC) to assess the variation between the mean reduced intraoral scanner files test and the control desktop scanner file and eventual inconsistencies. The volumes of the reduced mesh files were also compared with the 100% resolution intraoral mesh files to evaluate precision and trueness of the intraoral scanner.

Results: Reduced mesh files of 10%, 25%, 50%, 75% of the original scan yielded a percentage similarity average of 99.7%, indicating a very high precision value for the intraoral scanner. Also, the volumes of each associated mesh reduction slightly decreased with non-statistically significant results.

Conclusions: This study concluded that the chosen intraoral scanner for this study provided very high trueness (98.34%) and precision (99.7%), and also the volumes of reduced mesh files slightly decreased but were not statistically significant.