Influence of the supporting die structures on the fracture strength of all-ceramic materials

2011 ◽  
Vol 16 (4) ◽  
pp. 1105-1110 ◽  
Author(s):  
Munir Tolga Yucel ◽  
Isa Yondem ◽  
Filiz Aykent ◽  
Oğuz Eraslan
2020 ◽  
Vol 18 ◽  
pp. 228080002094732
Author(s):  
Satheesh B Haralur ◽  
Alaa Ali Alamrey ◽  
Shatha Abdulrahman Alshehri ◽  
Danyah Saeed Alzahrani ◽  
Mohammed Alfarsi

Objective: The aim was to compare the fracture strength of Molar endocrowns fabricated from different all-ceramic materials and various preparation designs. Materials and methods: Ninety extracted human molar teeth were root canal treated and randomly divided into three groups according to the all ceramic materials used for fabrication of the endocrowns ( n = 30): (1) Lithium disilicate (IPS e.max Press); (2) Polymer infiltrated ceramic (Vita Enamic); (3) High translucency zirconia (Ceramill Zolid HT). Each group was subdivided into 3 subgroups ( n = 10) according to the preparation design as 2 mm occlusal reduction, 4.5 mm occlusal reduction, and 4.5 mm occlusal reduction with 2 mm radicular extension. The endocrowns from each material were fabricated and surface treated according to the manufacturer’s recommendations. After cementation with self-adhesive resin luting cement, the specimens were stored in a humid environment for 72 hours and subsequently subjected to 5000 thermal cycles. After, a compressive, static-axial load was applied using a universal testing machine until failure. Load-to-failure was recorded (N) and the specimens were examined under a stereomicroscope to determine the failure type. The data was statistically analyzed using One-way ANOVA and Tukey HSD tests at p < 0.05. Results: The Lithium Disilicate endocrowns recorded the higher mean fracture strength for 4.5 mm occlusal thickness and 2 mm radicular extension at 3770.28 N and 3877.40 correspondingly. The High translucency zirconia endocrowns at conventional 2 mm thickness showed the highest mean fracture load (3533.34 N). Even though polymer infiltrated ceramic endocrowns displayed comparatively lesser fracture load; they recorded the predominantly favorable fractures. Conclusions: Increased occlusal thickness showed a significant improvement in fracture strength of lithium disilicate and polymer infiltrated ceramic molar endocrowns. Although the 2 mm radicular extension had the substantial enhancement of fracture strength in high translucency zirconia, it resulted in more unfavorable failure types.


2012 ◽  
Vol 82 ◽  
pp. 32-37 ◽  
Author(s):  
Malgorzata Plonska ◽  
Wojciech A. Pisarski ◽  
Beata Wodecka-Dus ◽  
Lukasz Cienki

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.


1988 ◽  
Vol 2 (1) ◽  
pp. 33-43 ◽  
Author(s):  
K. Asgar

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.


2006 ◽  
Vol 119 (21) ◽  
pp. 1815-1820 ◽  
Author(s):  
Yu-xing ZHANG ◽  
Wei-hong ZHANG ◽  
Zhi-yue LU ◽  
Ke-li WANG

2014 ◽  
Vol 72 (8) ◽  
pp. 623-629 ◽  
Author(s):  
Sibel Dikicier ◽  
Simel Ayyildiz ◽  
Julide Ozen ◽  
Cumhur Sipahi

2020 ◽  
Vol 10 (4) ◽  
pp. 940-946
Author(s):  
Shuang Liu ◽  
Hui Yan ◽  
Yuehang Gao

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.


2013 ◽  
Vol 873 ◽  
pp. 241-249
Author(s):  
Zhi Kai Wu ◽  
Ning Li ◽  
Wan Qian Zhao ◽  
Jia Zhen Yan

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.


2003 ◽  
Vol 17 (1) ◽  
pp. 55-60 ◽  
Author(s):  
V.S. Barath ◽  
F.-J. Faber ◽  
S. Westland ◽  
W. Niedermeier

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.


2013 ◽  
Vol 750-752 ◽  
pp. 529-532
Author(s):  
Cheng Fan

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


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