Statement Of The Problem: Monolithic zirconia restoration has been introduced to overcome the porcelain chipping. Different factors can affect the color of monolithic zirconia, so achieving the desired color in the restorations is considered as a challenge.
Purpose: The purpose of this study was to determine the effect of different foundation materials on the color of monolithic zirconia at different thicknesses.
Materials And Method: In this experimental study, thirty ceramic disks in three thicknesses (i.e. 0.6mm, 1.1mm and 1.5mm) were fabricated from high translucency shade A monolithic zirconia block. Disk shaped foundation materials were fabricated from nickel chromium alloy (Ni-Cr), non-precious gold alloy (NPG), zirconia, and shade A composite resin. The color was measured by a spectrophotometer. The color differences (∆E) in the control and the test groups were calculated. The data were analyzed using two way ANOVA and compared with the posthoc Tukey test (a=0.05).
Results: Ceramic thickness and foundation materials had a significant effect on the mean values of ∆E of monolithic zirconia ceramics (= 0.001). The highest amount of ∆E value was observed in NPG, while Ni-Cr resulted in the lowest ∆E. Unacceptable results (∆E>2.25) were observed for monolithic zirconia ceramics on NPG foundation material with a thicknesses of 0.6 and 1.1mm. The mean L values of all foundation materials were higher than those of the control group except for Ni-Cr. The highest a was seen in NPG and the mean b values of all tested foundation materials were higher than those of the control group except for Ni-Cr.
Conclusion: Increasing the thickness of monolithic zirconia decreased the color mismatch. High translucent monolithic zirconia could mask the color of Ni-Cr and zirconia in all three thicknesses (∆E<2.25), while it could not mask the color of NPG under thickness of 1.5mm.
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http://dx.doi.org/10.30476/DENTJODS.2021.85516.1131 | DOI Listing |
J Prosthodont Res
January 2025
Department of Restorative Dentistry, College of Dental Medicine, University of Sharjah, Sharjah, UAE.
Purpose: This retrospective clinical study aimed to evaluate the clinical outcomes of surveyed monolithic computer-aided design and computer-aided manufacturing (CAD/CAM) zirconia crowns for abutment teeth in removable partial dentures (RPDs).
Methods: Patients who received monolithic surveyed zirconia crowns were clinically examined. The crowns were examined according to the modified United States Public Health Service criteria, and Kaplan-Meier survival was determined.
Dent Mater
January 2025
Department of Prosthodontics and Periodontology, Bauru School of Dentistry, University of São Paulo, Bauru, SP 17012-901, Brazil.
Objectives: To characterize two experimental zirconia bilayer materials compared to their monolithic controls, before and after hydrothermal aging.
Methods: Commercial zirconia powders were utilized to fabricate two bilayer materials: 3Y-TZP+ 5Y-PSZ (3Y+5Y/BI) and 4Y-PSZ+ 5Y-PSZ (4Y+5Y/BI), alongside control groups 3Y-TZP (3Y/C), 4Y-PSZ (4Y/C), and 5Y-PSZ (5Y/C). Compacted specimens were sintered (1550 °C- 2 h, 3 °C/min), and half of them underwent hydrothermal aging (134 °C-20h, 2.
J Dent
January 2025
Senior Research and Teaching Assistant, Clinic of Reconstructive Dentistry, Center for Dental Medicine, University of Zurich, Plattenstrasse 11, Zurich 8032, Switzerland. Electronic address:
Objectives: A new abutment-free implant connection allows for direct screwing of FDPs on implants to avoid complications caused by cement rests or screw loosening, which may affect to screw torque and load distribution. The objective of this study was to test the initial (Fi) and final failure (Ff) loads and torque changes of abutment-free monolithic zirconia CAD-CAM fixed dental prostheses (FDPs) compared to titanium FDPs on different abutment designs.
Methods: Three-unit screw-retained FDPs (n = 50) on two implants (n = 100) were divided into groups (n = 10) based on the implant-abutment connection and material of the supra-structure: (1) abutment-free monolithic CAD-CAM zirconia FDP (Abut-free-Zr), (2) abutment-free veneered titanium FDPs (Abut-free-Ti), (3) monolithic zirconia FDPs with titanium base abutments (Zr-Ti-Base), (4) monolithic zirconia FDPs on multi-unit abutments (Zr-MU), (5) veneered titanium FDP on multi-unit abutments (Ti-MU).
J Prosthodont
January 2025
Department of Dentistry, Federal University of Rio Grande do Norte (UFRN), Lagoa Nova, Natal, Brazil.
Purpose: To assess the impact of staining and multiple firings on the mechanical, optical, and surface characteristics of zirconia-containing lithium silicate ceramics (ZLS).
Materials And Methods: Ninety ZLS discs (Suprinity, VITA Zahnfabrick) were divided according to the "Number of firings" protocol: Ctr-control, no characterization; SC-single firing cycle (for characterization, crystallization and staining simultaneously); and DC-double firing cycle (crystallization firing cycle was performed separately from the staining firing). Extrinsic pigmentation was performed to replicate the characterization of a monolithic restoration.
J Oral Implantol
January 2025
Department of Orthodontics and Pedodontics, Faculty of Dentistry, Van Lang University, Ho Chi Minh City, Vietnam.
The reverse scan technique offers several advantages, such as improvements of accuracy and visibility of critical anatomical structures, minimizing chair time, and providing better patient comfort. This was a case report successfully employing the reverse scan technique. A 72-year-old male patient desired to restore his teeth in both jaws, as he experienced difficulty eating and had never worn dentures.
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