Browsing by Author "Morgano, Steven"

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A study of dimensional accuracy in a partially edentulous arch by using a new alternate method to scan: An in-vitro study.
(Rutgers School of Dental Medicine, 2023) Kazim, Sohil; Kamel, Mohamed; Saghiri, Mohamed Ali; Morgano, Steven; Morgano, Steven
Objective: This study aims to determine the dimensional accuracy of 3D virtual casts generated by using 2D imaging (3DV) compared with a 3D scanned cast made with a table-top scanner (3DS) of a partially edentulous mandibular stone cast. The 3D scanned cast (3DS) was selected as a control because of its high precision and accuracy. Material and methods: A partially edentulous mandibular stone cast was scanned 5 times by using a 3D table-top scanner (Shining3D Dental, Zhejiang, China) to generate STL files. After a critical examination of all 5 STL 3D scans, 1 of them was chosen for the study with optimal landmarks and no surface defects. One hundred images of the mandibular stone cast were made by using a smartphone (iPhone 12 plus, Apple Inc, Cupertino, CA) from various angles. Then, the 2D images were converted to a 3D model by using the process of photogrammetry. The software used to render this process was Autodesk ReCap software (Autodesk ReCap, Inc, San Rafael, CA). The entire procedure was repeated 12 times to obtain 12 different data sets. To ensure repeatability of this alternate method to scan, all 3DV group casts were superimposed on each other to observe the difference between the superimposed casts. The selected 3D scanned cast from the 3DS group was compared with the 3DV group by using Autodesk Recap software to observe the match between the 2 groups. After completing the Autodesk Recap procedure, ImageJ software (National Institutes of Health, Bethesda, MD) was used to analyze and measure the dimensional difference between the selected 3DS cast and 3DV group. The data were analyzed by using the 1-sample t-test. Results: Twelve virtual casts of the 3DV group were overlapped on the selected 3D scanned cast which was obtained by using the table-top scanner. Significant overlaps were observed between both methods to scan for the partially edentulous mandibular stone cast (P < 0.05, CI 95%). Conclusion: The proposed method was highly accurate and comparable to a commercially available 3D table-top scanner. Clinical relevance: This new scanning technique is highly accurate and less expensive, easier to use and handle, and less space-consuming in the laboratory when compared with the results obtained from a 3D table-top scanner. Statement of problem: - High price of a 3D table-top scanner. - Size of the 3D table-top scanner.
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Accuracy of milled lithium disilicate crowns fabricated by using CBCT and IOS-based digital models
(Rutgers school of dental medicine, 2023) Jassoma, Elaf; Morgano, Steven; Muadab, Rami
Objectives To evaluate the trueness and precision of digital casts generated from intraoral scanning (IOS) and cone beam computed tomography (CBCT). Also, to assess the marginal integrity of milled lithium disilicate (LD) crowns that were fabricated from the IOS and CBCT digital casts. Materials and methods Tooth preparation for an all-ceramic crown was performed on a segmented cast that was later scanned as a master model. Scans were obtained; 10 conventional polyvinyl siloxane impressions were made that were scanned by using CBCT, 10 digital scans by using IOS, and 10 digital scans by using a desktop scanner. DICOM data of the CBCT were converted to STL files. The reference STL file was segmented and prepared for 3D comparison. The 3D comparison was performed to compare the IOS group and CBCT group to the reference STL files. Trueness was determined by measuring the root mean square (RMS) for each group. The data were analyzed by using paired samples t-test. The digital casts from each group were used to fabricate all-ceramic crowns; 10 crowns from a tabletop scanner (reference) digital model, 10 crowns from the IOS digital model, and 10 crowns from the CBCT digital model. Crowns were milled by using IPS emax CAD. The replica method was used to evaluate the marginal integrity of the milled crowns. The thickness of the cross-section of the replica was measured under scanning electron microscopy (SEM). Descriptive statistics of mean and standard error of trueness and marginal gaps for all groups were recorded and compared by applying paired sample t-test and repeated measures ANOVA test, respectively. All the data were analyzed by using statistical analysis software program SPSS, version 29.0. Results The accuracy of the CBCT group was shown to be statistically significantly different from that of the IOS group, based on the results of the paired sample t-test. Crowns made from digital models created by CBCT exhibited a marginal gap that was substantially higher (P < 0.001) than crowns made by using IOS models. Conclusions Within the limitations of this study, it can be concluded that CBCT generated models are statistically significantly less accurate when compared with a Trios 3 IOS, and when compared with a reference tabletop scanner. Additionally, lithium disilicate all-ceramic crowns fabricated from CBCT models recorded more marginal gap when compared with both the control and IOS groups.
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