RESUMEN
Maxillary defects pose challenges for prosthodontists, especially when patients have no remaining teeth. This clinical report describes rehabilitation with a complete denture obturator fabricated in 2 visits for an edentulous patient after a maxillectomy. The obturator base and artificial teeth were digitally designed and merged into a 1-piece prosthesis. Following a virtual reduction, the integrated prosthesis and a gingival veneer were calculated and then printed and bonded together to complete the fabrication. Balanced occlusion was achieved with the assistance of a digital occlusion analyzer at the insertion visit. This approach avoided base-tooth assembly deviations and provided a prosthesis with good patient-reported outcomes at the 6-month follow-up.
RESUMEN
STATEMENT OF PROBLEM: Current methods for assessing the accuracy of intraoral scanners (IOSs) that reduce errors and provide comprehensive data compared with previous methods are lacking. PURPOSE: The purpose of this in vitro study was to present a coordinate-based data analysis method to compare the accuracy of 5 IOSs for scanning completely dentate and partially edentulous casts. MATERIAL AND METHODS: Reference scans of 2 complete arch casts (completely and partially dentate) were digitized using a high-precision laboratory scanner (Ceramill Map 600). Each cast was scanned 10 times each using 5 IOSs (3Shape TRIOS 3, Planmeca Emerald, iTero Element 5D, Medit i500, and Shining Aoralscan 3). The dataset of all 10 test groups was analyzed by using a reverse engineering software program (Geomagic Wrap). Each test cast was aligned with the reference cast by 3-dimensional (3D) superimposition to determine the translation and rotation along the x-, y-, and z-axes. The dataset was analyzed using the Kruskal-Wallis and post hoc Bonferroni tests (α=.05). RESULTS: Significant differences were observed in all parameters among all scanners when scanning the same cast (P<.05). Significant differences were observed in at least 1 parameter for all scanners, except Element 5D after scanning different casts using the same scanner. Deviations in the test data generally relocated toward the mesial, buccal, and apical sides, and the casts were almost always rotated clockwise around the y-axis and counterclockwise around the z-axis. For the completely dentate cast, among all IOSs, Element 5D demonstrated the highest accuracy in most of the measured parameters, specifically in the y-axis translation (0.06[0.07] mm), z-axis translation (0.08[0.05] mm), and y-axis rotation (0.21[0.16] degree) (P<.05). For the partially edentulous cast, Element 5D displayed higher accuracy in most of the measured parameters, including the x-axis translation (0.11[0.14] mm) and z-axis rotation (0.12[0.18] degree) (P<.05). Emerald also displayed higher accuracy in most of the measured parameters, including the y-axis translation (0.05[0.08] mm) and y-axis rotation (0.14[0.12] degree) (P<.05). Element 5D exhibited no difference in the scanning accuracy between the 2 types of casts (P>.05). CONCLUSIONS: Element 5D offered a high level of accuracy and was an appropriate scanner for both situations. The method presented in this study provides a good assessment of accuracy deviations in complete arch scans using 3D coordinate-based data analysis.