Browsing by Author "Papaspyridakos, Panagiotis"

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Accuracy Assessment of 3D Printed Casts Using Zirconia Fixed Implant prosthesis: A Comparative Study in the Anterior Maxilla
(Saudi Digital Library, 2021-06-23) Abdeen, Layal; Papaspyridakos, Panagiotis; Chen, Yo-wei; Kostagianni, Aikaterini; Finkelman, Matthew; Papathanasiou, Aikaterini; Papaspyridakos, Panagiotis
Objective: The purpose of the present in-vitro study is to compare the accuracy of 3D printed casts generated from digital implant impressions with one intra-oral scanner (IOS) (Trios 3, 3Shape), from 4 3D printers, with the 3D accuracy of stone casts made by conventional implant impressions, in a partially edentulous anterior maxilla with two implants. Material and Methods: A maxillary cast with a partially edentulous anterior area was fabricated with the placement of two internal connection implants (Regular CrossFit, Straumann®, Switzerland). Stone casts (n=10) that served as a control were fabricated using the splinted open-tray impression technique. A digital impression was taken using a white light IOS (TRIOS, 3Shape), and a Standard Tessellation Language (STL) file was obtained. Four 3D printers were used to print the casts (n=10 from each 3D printer): a Straumann® P30+ (Straumann®, Switzerland) and a Varseo S (Varseo 3D printing system, BEGO®, Germany), which used digital light processing (DLP) technology; a Form 3b+ (Formlabs®, Somerville, MA, USA), which used stereolithography (SLA) technology; and an M2 Carbon (Carbon®, Redwood City, CA, USA), which used Continuous Liquid Interface Production™ (CLIP) technology. The master cast and all models generated from each group were digitized using the same IOS. Accuracy was evaluated digitally and laboratory. The obtained STL files were superimposed on the master cast STL file (reference) to evaluate the 3D accuracy digitally with inspection software (Geomagic Control X; 3D Systems) using the root mean square value (RMS). For prosthesis assessment, an implant screw-retained fixed zirconia prosthesis was fabricated and tested on each cast. Accuracy of fit was assessed using a screw resistance test and radiographic test. Results: The highest median RMS was found in the stone model group (94.6 μm) and the lowest median was in the M2 Carbon group (46.9 μm). The Kruskal-Wallis test revealed a statistically significant difference between the groups (p<0.001). For post-hoc comparisons, Dunn’s test with the Holm-Bonferroni correction resulted in a statistically significant difference in the four tests. The lowest p-value was for the comparison between the M2 Carbon and P30+ groups (p=0.002), with M2 Carbon exhibiting a significantly lower (RMS). The zirconia prosthesis fits adequately on all casts. Conclusion: Within the study’s limitations, the M2 Carbon printer in virtual analysis demonstrated statistically significant lower 3D deviations in root mean square than the Straumann® P30+ printer. Printed casts generated from M2 Carbon, Formlabs® Form 3b and BEGO® Varseo S demonstrated statistically significant lower 3D deviations in root mean square than stone models generated using a conventional implant impression for the present partially edentulous scenario with two implants. Using a screw-resistance test and radiographic assessment, the zirconia prosthesis fit was clinically acceptable on all models.
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Accuracy of fit of digitally fabricated prototypes with different printers: A Comparative Study
(2023-07-10) Alhumaid, Naif A; Papaspyridakos, Panagiotis
Aim: To test whether or not digitally fabricated (from two different 3D printers) prosthesis prototypes exhibit acceptable accuracy of fit on the master cast and compared the 3D printers in terms of accuracy of fit. Hypotheses: The digitally fabricated prosthesis prototypes (from two different 3D printers) generated from a complete digital workflow via the double digital scanning technique will exhibit acceptable accuracy of fit on the master cast. The Form 3b and Carbon M2 3D printers will be equally accurate in comparison to each other. Materials & Methods: A maxillary stone cast with 6 abutment-level implant analogs (SRA, Straumann) with adequate antero-posterior (AP) spread simulated a common clinical condition. This stone cast served as the master (reference) cast for taking digital impressions. A screw-retained prototypes prosthesis fabricated on the reference master cast following the Pro-Arch concept. The double digital scanning (DDS) technique was used to generate two STL files, then merged with the aid of CAD software into one master STL file. The master STL file was used to print digitally fabricated prototypes from 2 different printers (Form 3b+ and Carbon M2). Accuracy was evaluated in two methods: Radiographic assessment Radiographs were taken for each prototype to assess the accuracy of fit on each screw-retained abutment. Prior to taking each radiograph, the prototype was torqued to 15 Ncm to simulate the clinical scenario. Laboratory Analysis; Accuracy of Fit Assessment The accuracy of fit of the digitally generated prototype prostheses on the reference cast was tested. Two blinded clinicians tested the accuracy of the fit of the prosthesis on all prototypes using the screw-resistance test. Results: Out of the 62 digitally fabricated prototypes, 51 (82.26%) presented with accurate fit. The accuracy of fit ranged from 80.65% (25/31) for carbon m2 printer to 83.87% (26/31) for the form 3b lab printer. Conclusion: Digitally fabricated prosthesis prototypes can be generated with a complete digital workflow leading to clinically acceptable fit while reducing the number of appointments and treatment time.
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Evaluation of marginal and internal adaptation of fixed dental restorations on alveolar casts printed with different 3D printers.
(Tufts University School of Dental Medicine Boston MA, 2024) Eidah, Rawan; Papaspyridakos, Panagiotis
This in-vitro study evaluates the marginal and internal adaptation of fixed dental restorations created using three different 3D printing technologies: Carbon Digital Light Synthesis™ (Carbon DLS™), Straumann P30, and Formlabs Form 3B+. A reference cast was prepared, digitized, and printed using the respective 3D printers. Measurements of adaptation were conducted utilizing a light microscope. The findings revealed significant differences in adaptation among the printers, particularly in the incisal buccal regions, with the Carbon DLS™ exhibiting superior performance, achieving the smallest mean marginal gap compared to the others. In contrast, non-significant differences were observed in the middle and cervical regions. The results underscore the importance of selecting suitable 3D printing technology to meet clinical requirements, suggesting that Carbon DLS™ is especially effective for complex dental restorations that require high precision. This study contributes valuable insights into the evolving field of digital dentistry, emphasizing the role of technology in enhancing patient outcomes in dental restorations. Keywords: Dental Restoration, 3D Printing, Marginal Adaptation, Internal Adaptation, Digital Dentistry, Prosthodontics
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