Spectrophotometric evaluation of the optical influence of core build-up composites on all-ceramic materials

In the present work the influence of neodymium concentration (0-1at-%) and sintering conditions on 8/65/35 PLZT:Nd3+ ceramics were studied. All ceramic powders were synthesized by MOM technique from high purity raw materials (>99,9%), and subsequently sintered by free sintering and hot uniaxial pressing method. To analyze the powders and ceramics more the XRD, EDS SEM, and ferroelectric measurements were performed. Optical spectra were examined for all prepared samples, and their optical properties were analyzed using reflectance, excitation and luminescence measurements. The study gives a detailed account of the relationships between doping and preparing conditions on the basic physical and dielectric and optical properties of obtained ceramic materials.

Download Full-text

Casting Metals in Dentistry: Past - Present - Future

Advances in Dental Research ◽

10.1177/08959374880020011701 ◽

1988 ◽

Vol 2 (1) ◽

pp. 33-43 ◽

Cited By ~ 11

Author(s):

K. Asgar

Keyword(s):

Basic Research ◽

Ceramic Materials ◽

Computer Search ◽

Washington Dc ◽

Laboratory Equipment ◽

The Past ◽

All Ceramic ◽

Metal Group ◽

Composition Properties ◽

Future Work

This article deals mainly with the development of dental casting techniques and formulation of the different groups of alloys used in the fabrication of ceramo-metal restorations. It is recognized that in order for the quality of dental cast restorations to be improved, having alloys with the proper composition is not enough. Biocompatibility, good mechanical and physical properties, longevity of the restoration, compatibility with porcelain, and a simple manipulative technique are as important. Researchers have contributed to different aspects of dental castings and have made cast restorations what they are today. Unfortunately, much of the original basic research has been overlooked by present investigators, who have duplicated studies conducted in the past without realizing that the study had already been performed and the research had been published. The main reason for this is that abstracts of articles published prior to 1975 are not available through a library computer-search system. To obtain copies of articles published prior to 1975, one has to search the literature to know where they were published. This article provides references for much of the past work in this area. Also, dental libraries do not carry copies of U.S. patents. This places the majority of researchers located at dental schools at a disadvantage. They are not familiar with what the patents claim, what is taught, and why certain elements are added or eliminated from alloys and investment materials. This article also provides the numbers of many U.S. patents. By having the patent number, one can obtain the text of the patent from the U.S. Patent Office in Washington, DC. Since esthetics plays an important role in today's society, emphasis will be given only to alloys designed for fabrication of ceramo-metal restorations. Many ceramo-metal alloys are available today, and they are classified differently by different individuals. In this article, classification will be based on the major components of these alloys, as well as on a chronological introduction of one group leading to the development of the next group. Based on this, one can classify these alloys into six major groups. Chemical composition, properties, and the developers of these alloys, along with their U.S. patents, are given. Recently, two types of all-ceramic restorations have been introduced. The main advantage of the all-ceramic restoration is its superior esthetic quality compared with that of ceramo-metal restorations. Their main disadvantages are low strength and ductility. Their strength, however, is sufficient for single-unit restorations, but not for bridgework. The use of titanium for dental restorations has also been studied, and it has been found to be suitable. Future Studies - Future work should be devoted to the following: (1) the development of stronger and more ductile ceramic materials: (2) further study of the promising palladium alloys from the noble metal group and titanium alloys from the base metal group; (3) the development of easier and less-time-consuming techniques for the fabrication of dental appliances; (4) the development of a powder technique rather than a cast technique for future fabrication methods; and (5) the development of new laboratory equipment, e.g., a single sintering oven capable of sintering both ceramic and metallic particles, which would be accepted if the powder technique is developed.

Download Full-text

Effect of varying core thicknesses and artificial aging on the color difference of different all-ceramic materials

Acta Odontologica Scandinavica ◽

10.3109/00016357.2013.879997 ◽

2014 ◽

Vol 72 (8) ◽

pp. 623-629 ◽

Cited By ~ 13

Author(s):

Sibel Dikicier ◽

Simel Ayyildiz ◽

Julide Ozen ◽

Cumhur Sipahi

Keyword(s):

Artificial Aging ◽

Color Difference ◽

Ceramic Materials ◽

All Ceramic

Download Full-text

Research on the Effect of Repairing Anterior Teeth with All-Ceramic Veneer Based on CT Images

Journal of Medical Imaging and Health Informatics ◽

10.1166/jmihi.2020.2958 ◽

2020 ◽

Vol 10 (4) ◽

pp. 940-946

Author(s):

Shuang Liu ◽

Hui Yan ◽

Yuehang Gao

Keyword(s):

Light Transmission ◽

Chemical Properties ◽

Ct Scanning ◽

Ceramic Materials ◽

Original Data ◽

Image Method ◽

Finite Element Software ◽

Anterior Teeth ◽

All Ceramic ◽

Simulation Results

IPS e.maxPress all-ceramic materials have good physical and chemical properties, biocompatibility, light transmission similar to natural teeth and excellent aesthetic properties, so they are widely used in clinical practice. In this study, the anterior porcelain veneer was made by using IPS e.maxPress hot-pressed casting ceramic under the guidance of DSD software aesthetic design, and its clinical aesthetic repair effect and success rate were evaluated, which provided a useful reference for clinical aesthetic restoration work. The original data was obtained by using the medical image method; the DICOM data obtained by CT scanning was input into the reverse engineering software for image processing and data optimization by using the reverse technique to obtain the real tooth and mandible model. The 3D modeling software is used to establish the implant model and the associated tissue model, and the assembly is completed. The finite element software is introduced, the contact type between the tissues is set, and the clinical simulation results are compared to analyze the simulation results. Practice provides a better surgical solution.

Download Full-text

Low Temperature Degradation of Y-TZP Ceramic for Dental Applications

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.873.241 ◽

2013 ◽

Vol 873 ◽

pp. 241-249

Author(s):

Zhi Kai Wu ◽

Ning Li ◽

Wan Qian Zhao ◽

Jia Zhen Yan

Keyword(s):

Low Temperature ◽

Substantial Reduction ◽

Tetragonal Zirconia ◽

Ceramic Materials ◽

Dental Ceramics ◽

All Ceramic ◽

Long Time ◽

Core Thickness ◽

Dental Applications

Yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramic has been recently introduced into prosthetic dentistry for the fabrication of crowns and fixed partial dentures (FPDs). The mechanical properties of Y-TZP are the highest ever reported for the all-ceramic materials. This is favorable for the fabrication of multi-unit posterior bridges and the substantial reduction in core thickness. However, Y-TZP ceramic is susceptible to low temperature degradation (LTD), which is detrimental to the long-time survival and aesthetics of zirconia restorations in vivo. This review summarizes the characterization, mechanisms, and influencing factors of the LTD in dental Y-TZP ceramic. In addition, the recent trend of exploring high aging resistant zirconia-based dental ceramics is discussed.

Download Full-text

Spectrophotometric Analysis of All-ceramic Materials and Their Interaction with Luting Agents and Different Backgrounds

Advances in Dental Research ◽

10.1177/154407370301700113 ◽

2003 ◽

Vol 17 (1) ◽

pp. 55-60 ◽

Cited By ~ 62

Author(s):

V.S. Barath ◽

F.-J. Faber ◽

S. Westland ◽

W. Niedermeier

Keyword(s):

Glass Ionomer Cement ◽

Color Difference ◽

Ceramic Materials ◽

Spectrophotometric Analysis ◽

Color Variation ◽

Luting Agents ◽

Luting Agent ◽

All Ceramic ◽

Cielab System ◽

Final Color

In this study, two All-Ceramic (AC) materials—Empress 2 (EMP) (Ivoclar Vivadent AG, Schaan, Liechtenstein) and In-Ceram ALUMINA (ICA) (Vita Zahnfabrik, Bad Säckingen, Germany)—were analyzed, along with the effects of 3 luting agents— viz. Zinc Phosphate cement (ZNPO, PhospaCEM PL, Ivoclar Vivadent AG, Schaan, Liechtenstein), Glass Ionomer Cement (GIC, Ketac-Cem Radiopaque, ESPE Dental AG, Seefeld, Germany), and Compolute (COMP, ESPE Dental AG, Seefeld, Germany)—on the final color, using the CIELab system. Color differences (DeltaL, Deltaa, Deltab, and DeltaE) were calculated for samples with luting agents and for samples without luting agents with standard white and black backgrounds, with the use of a spectrophotometer, Luci 100 (Dr. Lange, Berlin, Germany). One-way ANOVA for DeltaL, Deltaa, Deltab, and DeltaE within both the AC systems, with and without luting agents, showed significant contributions of the background (p < 0.05). EMP was seen to be more translucent than ICA. Darker ceramics showed less color variation. Luting agents altered the final color of the restoration. ZNPO was least translucent, followed by GIC and COMP. Marginal increases in thicknesses of ICA samples (0.4 mm) do not show a statistically significant color difference. No method exists to predict the outcome of an AC restoration based on consideration of the luting agent and the background color.

Download Full-text

Fracture Mechanics Analysis of GI All-Ceramic Crowns

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.750-752.529 ◽

2013 ◽

Vol 750-752 ◽

pp. 529-532

Author(s):

Cheng Fan

Keyword(s):

Clinical Application ◽

Process Analysis ◽

Failure Process ◽

Chemical Properties ◽

Ceramic Materials ◽

All Ceramic ◽

Ceramic Crowns ◽

Analysis System ◽

Physical And Chemical ◽

Ceramic Crown

Dental ceramic materials have approximate color and translucency with natural tooth, which is unmatched by other restorative materials. Because of its beautiful appearance, good physical and chemical properties, all-ceramic crown restorations are more widely used., However, due to the brittleness of ceramics and the stress mismatch between different materials, dropping or fracture phenomenon of porcelain veneer is often occurred in clinical application during the service period of all-ceramic crowns. The porcelain veneer failure mechanism is still not very clear, in this paper, the force performance of all-ceramic crowns is analyzed using the RFPA (realistic failure process analysis) system. The crack initiation, propagation and failure process of all-ceramic crown can be clearly observed and the research results provide guidance for clinical application

Download Full-text

Colour stability of three modern ceramic materials after repeated firing

10.51415/10321/2566 ◽

2017 ◽

Author(s):

◽

Ansuya Naidoo

Keyword(s):

Ceramic Materials ◽

Sem Analysis ◽

Control Group ◽

Firing Cycle ◽

Colour Stability ◽

Chi Square ◽

Final Thickness ◽

Multivariate Tests ◽

All Ceramic ◽

Before And After

Background Shade matching is a challenging aspect of aesthetic dentistry (Vichi et al., 2011). For a long time, aesthetically pleasing prostheses have been achieved using the porcelain-fused-to-metal crown whereby the metal is masked with an opaque layer and then consecutive layers of veneering ceramic are built up (McLean, 1979). The growing popularity of all-ceramic restorations has created a need for an understanding of its colour characteristics in preference to porcelain fused to metal restorations. The study aims to assist dental technicians in making a more informed decision when choosing an all-ceramic system in terms of colour stability. Objectives The objectives were to identify colour changes of the zirconia after each firing cycle and defining if there are any microstructural changes in the zirconia cores after subsequent firing. Methods This is a quantitative study with a sample size of eighteen which was used for each experimental group. Green state zirconia blocks from Cercon (Dentsply DeguDent, USA), Lava (3M ESPE,USA), and Zirkon Zahn (Zirkonzahn Gmbh, Bruneck, Italy) were trimmed, finished and sintered to a final thickness of 0.5mm according to the manufacturers’ instructions. Each sample group was obtained directly from the manufacturer. In each group, nine specimens were shaded and nine were unshaded. The colour of each specimen was recorded before being exposed to firing cycles. This data formed the control group. All specimens were subjected to three firings and spectrophotometer reading. After each firing, SEM analysis was done after one and three firings. There was a total of thirty six specimens x three firings; n = 108. The raw data for the statistical analysis was obtained from the spectrophotometer readings recorded after the firings (n=108). The data of the study was analyzed using the SPSS version 22.0. The data were compared among the three groups using Pearsons chi square tests, where the data of the firings were measured as a binary or nominal variable, and using t-tests where a measured normally distributed variable was compared. The general linear model (GLM) looked at combinations of the variables and their effects on the dependant variable. The Multivariate tests table indicates the actual result of the one-way MANOVA. Results The Cercon results for both the control and experimental groups reveal the same result patterns and was maintained before and after firing. Lava also revealed the same results before and after firing, however, the cores in the control group differed in colour. The Zirkon Zahn system proved to be the least stable in colour. Conclusion This study supports the hypothesis that colour differences would occur relative to the number of firings for shaded zirconia. It can be concluded that Cercon displayed the most stable results in terms of colour. The acumen gained in this study may better assist dental technicians in their selection of an all-ceramic zirconia system.

Download Full-text

Influence of repeated firings on the color parameters of two different all-ceramic materials

Color Research & Application ◽

10.1002/col.22219 ◽

2018 ◽

Vol 43 (4) ◽

pp. 606-611 ◽

Cited By ~ 1

Author(s):

Gönüldaş Fehmi ◽

Çelik Ersan ◽

Öztürk Caner

Keyword(s):

Ceramic Materials ◽

Color Parameters ◽

All Ceramic

Download Full-text