The Effect of Open Source CAD/CAM Technology on the Accuracy of Digital Images of Fixed Partial Denture Preparations
Abstract
Summary
A significant change taking place this century is the introduction of digital technology into dental practice; “Digital Dentistry” is becoming more prevalent each year. Recently, digital impression techniques with three-dimensional (3D) intra-oral scanners have been attracting attention gaining in popularity around the world. With labs and practices worldwide continuing to increase implementation of Computer Aided Design, Computer Aided Manufacture (CAD/CAM) systems, a crossroads between open and closed systems appear. Since technology is constantly changing, most dentists nowadays tend to be attracted to open systems for their greater flexibility and compatibility, allowing them to follow the technological trends of the technological age.
Therefore, in our present study, the effect of open source CAD/CAM technology on the accuracy of digital images of fixed partial denture preparations was investigated under laboratory conditions.
A typodont with a missing upper right second premolar and prepared abutments; upper right first premolar and upper right first molar (for a 3 unit fixed partial denture all ceramic restoration) was used as the basic model. It was scanned by the three investigated scanners; Omnicam (Cerec), Trios 3 (3Shape) and CS3600 (Carestream)with the inEos x5 extraoral scanner acting as the reference scanner. In addition, a three unit fixed partial denture restoration was virtually designed on each of the investigated systems, then each design was exported to the other two systems, reopened and saved again as new datasets. The exported, newly saved design datasets (Remote design) on each of the two systems were compared to the original design (Host design) to evaluate the effect of exporting design datasets among the different systems. All datasets were obtained in standard tessellation language (STL) file format. Values for trueness and precision were evaluated using a three-dimensional (3D) superimposition method with special 3D difference analysis software (Geomagic control X).
Regarding precision, three dimensional analysis showed no statistically significant difference between the three scanners “Omnicam, Trios 3 and CS 3600”. However, two dimensional analysis revealed that Omnicam showed the statistically significantly highest mean (least precision). On the other hand three dimensional analysis for trueness revealed that there was no statistically significant difference between Trios 3 and Carestream scanners ; both showed statistically significantly better trueness than Omnicam.
The results of the study indicate that the three investigated scanners were able to produce both repeatable and reliable optical scans. The exchange of fixed Partial Denture designs between the investigated systems did not have a statistically significant effect on the accuracy of the virtual designs. From these results, it would be possible to speculate that open source CADCAM technology may be able to provide a more flexible workflow without jeopardizing the quality of restorations. Further investigation of the complete fabrication process of milled restorations using open source CADCAM technology is needed to assure such an assumption.