Marginal Discrepancy and Internal Fit of Bi-Layered and Monolithic Zirconia Fixed Dental Prostheses: An In Vitro Study
This in vitro study evaluated the influence of restoration design (bi-layered vs. monolithic) and manufacturing technique on the marginal discrepancy and internal fit of 3-unit zirconia fixed dental prostheses (FDPs). Mandibular second premolars and second molars were prepared as abutments in a 3-un...
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MDPI AG
2023-10-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/13/20/11461 |
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| author | Majed M. Alsarani Amin S. Rizkalla Joseph Fava Thomas W. Coyle Omar El-Mowafy |
| author_facet | Majed M. Alsarani Amin S. Rizkalla Joseph Fava Thomas W. Coyle Omar El-Mowafy |
| author_sort | Majed M. Alsarani |
| collection | DOAJ |
| description | This in vitro study evaluated the influence of restoration design (bi-layered vs. monolithic) and manufacturing technique on the marginal discrepancy and internal fit of 3-unit zirconia fixed dental prostheses (FDPs). Mandibular second premolars and second molars were prepared as abutments in a 3-unit zirconia bridge to develop four groups (<i>n</i> = 10 FDPs): MZ: Monolithic zirconia FDPs, ZL: zirconia framework veneered by the hand-layering technique, ZP: zirconia framework veneered by the heat-pressed technique, and CAD-on: zirconia framework veneered by CAD/CAM lithium-disilicate glass–ceramic. All the zirconia FDPs were cemented to their corresponding die replicas using dual-cure resin cement and were subjected to compressive cyclic loading at a load range for half a million cycles using a universal testing machine. FDPs were sectioned mesiodistally to measure the marginal gap and internal fit using scanning electron microscopy. The measurements were taken at pre-assigned points of each abutment. Data were statistically analyzed via a Kruskal–Wallis test (α = 0.05). No significant differences were found between the monolithic and bi-layered zirconia groups in terms of the marginal discrepancy. However, there was a significant difference in the marginal gap between the zirconia groups. The marginal gap between monolithic and bi-layered zirconia FDPs was within the clinically acceptable range (<100 μm). Comparable mean values of the marginal gaps of 3-unit monolithic and veneered zirconia FDPs were found. Therefore, the FDP design and veneering methods did not affect the marginal discrepancy. However, the mean internal gap varied among the experimental groups. As the current in vitro investigation demonstrated equivalent mean values of marginal gaps of both 3-unit monolithic and bi-layered zirconia FPDs, the use of monolithic 3-unit zirconia FPDs would be a viable alternative fabrication technique. |
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| last_indexed | 2024-03-10T21:28:08Z |
| publishDate | 2023-10-01 |
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| series | Applied Sciences |
| spelling | doaj.art-2bbdcc97230c46858d38760fcf9415922023-11-19T15:32:31ZengMDPI AGApplied Sciences2076-34172023-10-0113201146110.3390/app132011461Marginal Discrepancy and Internal Fit of Bi-Layered and Monolithic Zirconia Fixed Dental Prostheses: An In Vitro StudyMajed M. Alsarani0Amin S. Rizkalla1Joseph Fava2Thomas W. Coyle3Omar El-Mowafy4Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh 12372, Saudi ArabiaDepartment of Chemical and Biochemical Engineering, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5B9, CanadaProsthodontics, Faculty of Dentistry, University of Toronto, Toronto, ON M5G 1G6, CanadaDepartment of Materials Sciences and Engineering, University of Toronto, Toronto, ON M5G 1G6, CanadaRestorative Dentistry, Faculty of Dentistry, University of Toronto, Toronto, ON M5G 1G6, CanadaThis in vitro study evaluated the influence of restoration design (bi-layered vs. monolithic) and manufacturing technique on the marginal discrepancy and internal fit of 3-unit zirconia fixed dental prostheses (FDPs). Mandibular second premolars and second molars were prepared as abutments in a 3-unit zirconia bridge to develop four groups (<i>n</i> = 10 FDPs): MZ: Monolithic zirconia FDPs, ZL: zirconia framework veneered by the hand-layering technique, ZP: zirconia framework veneered by the heat-pressed technique, and CAD-on: zirconia framework veneered by CAD/CAM lithium-disilicate glass–ceramic. All the zirconia FDPs were cemented to their corresponding die replicas using dual-cure resin cement and were subjected to compressive cyclic loading at a load range for half a million cycles using a universal testing machine. FDPs were sectioned mesiodistally to measure the marginal gap and internal fit using scanning electron microscopy. The measurements were taken at pre-assigned points of each abutment. Data were statistically analyzed via a Kruskal–Wallis test (α = 0.05). No significant differences were found between the monolithic and bi-layered zirconia groups in terms of the marginal discrepancy. However, there was a significant difference in the marginal gap between the zirconia groups. The marginal gap between monolithic and bi-layered zirconia FDPs was within the clinically acceptable range (<100 μm). Comparable mean values of the marginal gaps of 3-unit monolithic and veneered zirconia FDPs were found. Therefore, the FDP design and veneering methods did not affect the marginal discrepancy. However, the mean internal gap varied among the experimental groups. As the current in vitro investigation demonstrated equivalent mean values of marginal gaps of both 3-unit monolithic and bi-layered zirconia FPDs, the use of monolithic 3-unit zirconia FPDs would be a viable alternative fabrication technique.https://www.mdpi.com/2076-3417/13/20/11461marginalinternalzirconiaCAD/CAMprostheses |
| spellingShingle | Majed M. Alsarani Amin S. Rizkalla Joseph Fava Thomas W. Coyle Omar El-Mowafy Marginal Discrepancy and Internal Fit of Bi-Layered and Monolithic Zirconia Fixed Dental Prostheses: An In Vitro Study Applied Sciences marginal internal zirconia CAD/CAM prostheses |
| title | Marginal Discrepancy and Internal Fit of Bi-Layered and Monolithic Zirconia Fixed Dental Prostheses: An In Vitro Study |
| title_full | Marginal Discrepancy and Internal Fit of Bi-Layered and Monolithic Zirconia Fixed Dental Prostheses: An In Vitro Study |
| title_fullStr | Marginal Discrepancy and Internal Fit of Bi-Layered and Monolithic Zirconia Fixed Dental Prostheses: An In Vitro Study |
| title_full_unstemmed | Marginal Discrepancy and Internal Fit of Bi-Layered and Monolithic Zirconia Fixed Dental Prostheses: An In Vitro Study |
| title_short | Marginal Discrepancy and Internal Fit of Bi-Layered and Monolithic Zirconia Fixed Dental Prostheses: An In Vitro Study |
| title_sort | marginal discrepancy and internal fit of bi layered and monolithic zirconia fixed dental prostheses an in vitro study |
| topic | marginal internal zirconia CAD/CAM prostheses |
| url | https://www.mdpi.com/2076-3417/13/20/11461 |
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