Klink, A.A. (Jarno) (2018) Het verkrijgen van een digitaal gebitsmodel uit een conventionele gebitsafdruk zonder het gebruik van een gipsmodel. thesis, Dentistry.
Full text available on request.Abstract
Background: Although there are plenty of studies about intra-oral scanning methods, the conventional impression is common sense in general practice. Conventional impressions still offer the most accurate details which is important for full-arch restorative treatments. However, using this method means performing a number of actions, mainly in the dental laboratory, where small inaccuracies can occur. For this reasons, new workflows are being sought-after to digitize this process with the research question: Which accuracy can be obtained from direct scanning of impression materials in comparison with the accuracy of scanning the plaster model from the same print (the conventional method)? Is there also a difference for the accuracy of this method for various impression materials? Objective: Analyzing the accuracy of direct scanning of dental impressions with a laboratory scanner to develop a new method in order to obtain digital models Method: This is a pilot study, patient-related, experimental research in a study population of 12 healthy, male volunteers with an average age of 23.5 (SD, 2.6) years. Three conventional full-arch impressions were taken from the upper jaw, each of a different material; polyether (PE), vinylsiloxanether (VSE) and an irreversible hydrocolloid (ALG). These impressions were scanned (SA-group), with a M400 laboratory scanner (Amann Girrbach), where after they were poured into hardstone plaster. The obtained gypsum models were also scanned with the same laboratory scanner (SG-group). The digital models were compared in software DentalDesign (3Shape) with the golden standard, the gypsum model of the PE-impression. The deviation was noted at twenty fixed points per digital model, after which the average deviation of the entire jaw of the corresponding SA- and SG-groups was compared. At last an additional distinction was made between the points in depth and width. Results: The direct scanning of impression materials gives a significantly greater deviation than the current way of working, scanning a plaster model. In addition to the difference between the related SA and SG-groups, the accuracy (the deviation) also differ between the various impression materials. The average deviation for PE, VSE and ALG was respectively; 0 μm (SG), 39.3 μm (SA); 53.1 μm (SG), 75.9 μm (SA); 76.2 μm (SG) and 92.1 μm. Points in width gave a lower value in deviation from points in depth, only for SAalg and SGalg significantly . Conclusion: Scanning of the impression material gives, regardless of the material PE, VSE and ALG, significantly more inaccuracy compared to the scanning of the plaster model at the twenty selected fixed points in this study. Immediate scanning of the impressions with PE, VSE and ALG therefore does not offer any advantage over the scanning of plaster, but often for greater inaccuracy.
| Item Type: | Thesis (UNSPECIFIED) |
|---|---|
| Supervisor name: | Pelt, Dr. A.W.J. van and Veen, Dhr. M.J. van der |
| Faculty: | Medical Sciences |
| Date Deposited: | 18 Nov 2021 09:25 |
| Last Modified: | 22 Nov 2021 11:22 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/2795 |
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