3Dprinted Markers Assisted Precision Comparison: Intraoral Scanning Vs. Silicone Impression

This study aims to compare the accuracy of intraoral scanning and silicone impressions using 3D printed markers, which assist in the data fitting and comparison of abutment teeth contour. Trapezoidal markers (designed by Materialise Magics 27) were printed with HeyGears A2D. Markers were temporarily bonded to the adjacent teeth. After recording the abutment teeth and the markers with the 3Shape intraoral scanner, the plaster models from silicone impressions were scanned using a 3Shape-F8 model scanner. The STL files were compared after markers fitting. The size of the markers post-printing, in the intraoral scanning data, and the plaster model scanning data were compared. The differences among the buccal/lingual part, incisal/middle/cervical 1/3 regions of the abutment teeth in the intra-oral scanning and the plaster model scanning data were compared. Concerning the difference compared with the printed size of markers, the plaster model is more significant than the oral scanning. After fitting with the markers, concerning the difference between the intraoral scanning and plaster model scanning, the cervical 1/3 shoulder region exhibited greater significance compared to the incisal 1/3 and middle 1/3 regions. The accuracy of intraoral scanning is more accurate than silicone impressions of sharp lines and undercut areas. The potential impact of saliva and gingival tissue collapse on the clarity of the shoulder region during data acquisition might cause a great difference in the cervical 1/3 shoulder region, which provides more insights into our daily clinical practice.