Background And Aims: To verify the color match of metal-ceramic and full ceramic crowns, using instrumental methods.
Methods: A number of 153 teeth (anterior and posterior teeth), in 62 patients, were restored with metal ceramic (MC, n=119), pressed-ceramic (PC, n=28), and zirconia-ceramic (ZC, n=6) full coverage crowns. The shade of a reference natural tooth was recorded instrumentally with a dental spectrophotometer (Vitaeasyshade Advance 4.0) in "single tooth measurement", which provided the base color in Vita Classic (VC) and Vita 3D Master shades (3D).For verifying the outcome of the restoration "verify restoration" mode was used, and ΔE values were recorded for both VC and 3D Master shade guides. Moreover, matching symbols were also recorded (***=good, **=fair, *=poor). Descriptive statistics was performed and data were analyzed (One-sample z-Test, α=0.05) for comparison with visual thresholds in dentistry (Perceptibility Threshold - PT=1.2 and Acceptability Threshold - AT=2.7).
Results: The data did not follow a normal distribution (Kolmogorov-Smirnov test, p<0.05). Recorded color difference was significantly higher than PT and AT, for all types of restorations, regardless of the coding system (p<0.05). For MC crowns in 2.52% (4.20% for 3D) of the cases the color difference was smaller than PT, in 19.32% (the same for 3D) of cases was between PT and AT, and in 78.15% (76.47% for 3D) of cases was higher than the AT. For PC crowns in 3.57% (0% for 3D) of the cases the color difference was smaller than PT, in 25% (32.14% for 3D) of cases was between PT and AT, and in 71.42% (67.85% for 3D) of cases was higher than the AT. In the case of ZC crowns none of the restorations had color difference smaller than PT, but in 16.66% of cases was between PT and AT, and in 83.33% of cases was higher than the AT, for both VC and 3D.
Conclusion: Within the limitations of the study, a better color match was achieved in the case of pressed ceramic crowns, made of lithium disilicate. In most of the situations the color difference between the restoration and the reference tooth exceeded the perceptibility thresholds, but the matching was recorded as "fair" by the spectrophotometer.
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http://dx.doi.org/10.15386/mpr-1330 | DOI Listing |
Oper Dent
January 2025
Nathaniel C Lawson, DDS, PhD, director of Master of Science in Dental Biomaterials program and associate professor, Department of Clinical and Community Sciences, University of Alabama at Birmingham School of Dentistry, Birmingham, AL, USA.
Objective: This study aimed to assess the fracture resistance of chairside computer assisted design and computer assisted manufacturing (CAD-CAM) lithium disilicate partial and full-coverage crowns and veneers for maxillary canines.
Methods And Materials: Forty-eight restorations for maxillary right canines (12 per group) were designed as follows: (1) partial crown with finish line in the upper middle third; (2) partial crown with finish line in the lower middle third; (3) traditional labial veneer; and (4) traditional full-coverage crown. Restorations were fabricated out of lithium disilicate (Amber Mill, Hassbio) using a chairside CAD-CAM system (Cerec Dentsply Sirona).
Int J Biol Macromol
December 2024
Graduate Program in Chemistry, Federal University of Alfenas, Alfenas, MG 37130-001, Brazil; Institute of Chemistry, Federal University of Alfenas, Alfenas, MG 37130-001, Brazil. Electronic address:
The objective of this study was to produce new and renewable bio-based plasticizers from used soybean cooking oil (USCO). First, USCO was completely converted into free fatty acids (FFAs) using lipase from Candida rugosa. Next, these FFAs were enzymatically esterified with benzyl alcohol in solvent-free systems.
View Article and Find Full Text PDFJ Funct Biomater
November 2024
Department of Occlusion, Fixed Prosthodontics and Dental Materials, School of Dentistry, Federal University of Uberlandia, Uberlandia 38405-320, Minas Gerais, Brazil.
This study aimed to evaluate the scanning time and marginal fit of CAD/CAM crowns fabricated using different intraoral scanning systems (IOS) (O1-Omnicam 1.0, O2-Omnicam 2.0, PS-Primescan).
View Article and Find Full Text PDFDent J (Basel)
November 2024
Department of Prosthetic Dental Science, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia.
: This study aimed to investigate the fracture strength of a novel-designed Zirconia crown before and after access opening, and to evaluate the mode of fracture and the time needed for initial penetration through the crown. : This study involved the design and testing of 60 zirconia crowns, divided into three groups (20 crowns each) to compare different structural designs. Group 1 (Control) used a conventional full zirconia crown.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Tianjin Key Laboratory for Photoelectric Materials and Devices, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, P.R. China.
Beta-AlO-based solid-state sodium metal batteries are some of the best options for large-scale energy storage systems because of their high energy density, high-level safety, and low cost. Nevertheless, their room-/low-temperature operation remains challenging due to low ionic conductivity of Beta-AlO electrolyte and weak solid-solid contact of the Na/Beta-AlO interface. Herein, an integrated strategy was developed via electrolyte optimization and interface regulation, in which Cu as a stabilizing agent was incorporated into Beta-AlO to improve density and ionic conductivity and the InS interface layer was introduced between the Na anode and solid electrolyte to induce the in situ formation of a mixed conductive layer (Na-In alloy and NaS).
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