Fracture toughness of zirconia ceramic crowns made by feather-edge tooth preparation design

Background/Aim. Fracture toughness determines functional crown strenght and prevents damages on ceramics during mastication. There is a lack of relevant literature data about fracture toughness of crowns made by feather-edge preparation. Mechanical testing of ceramic samples is supposed to show if feather-edge tooth preparation is a successful method for making ceramic crowns without any risk of reduction of their mechanical properties. This research was done to establish effects of feather-edge tooth preparation on fracture toughness of single zirconia ceramic crowns. Methods. The research was performed as an experimental study. Sixty (60) ceramic crowns were made on non-carious extracted human premolars. Thirty (30) crowns were made on the basis of feather-edge preparation (experimental group I). The group II included 30 crowns made on 1 mm rounded shoulder. Crowns fabrication was executed on a copy mill production system ?Zirkonzahn? (Zirkonzahn GMBH, Gais, Germany). The spherical compression test was used to determine fracture toughness, using 6 mm diameter ceramic ball. Fracture load for damaging ceramic crown was recorded on a universal testing machine - Zwick, type 1464, with the speed of 0.05 mm/min. Results. The results of this research introduced significant differences between fracture toughness of ceramic samples in every examined group. However, fracture toughness of crowns from both group was above 2 000 N, what was double beyond a recommended value. The mean value of fracture toughness in the feather-edge group was 2 090 N, and in shoulder group it was 2 214 N. Conclusion. This research showed a high fracture toughness of zirconia crowns made on feather-edge preparation. The examined crowns showed a fracture resistance at a sufficient distance in relation to the minimum values of functional loads. Further research of functional loads of these crown is necessary, as well as research of marginal adaptation of cemented crowns and gingival inflammatory response.

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Micro Fracture Toughness Testing of TiAl Based Alloys with a Fully Lamellar Structure

MRS Proceedings ◽

10.1557/proc-842-s5.44 ◽

2004 ◽

Vol 842 ◽

Author(s):

K. Takashima ◽

T. P. Halford ◽

D. Rudinal ◽

Y. Higo ◽

M. Takeyama

Keyword(s):

Fracture Toughness ◽

Focused Ion Beam ◽

Ion Beam ◽

Testing Machine ◽

High Fracture Toughness ◽

Fracture Mechanisms ◽

High Fracture ◽

Fundamental Information ◽

Micrometer Scale ◽

Fully Lamellar

ABSTRACTA micro-sized testing technique has been applied to investigate the fracture properties of lamellar colonies in a fully lamellar Ti-46Al-5Nb-1W alloy. Micro-sized cantilever specimens with a size ≈ 10 × 10 × 50 μm3 were prepared by focused ion beam machining. Notches with a width of 0.5 μm and a depth of 5 μm were also introduced into the micro-sized specimens by focused ion beam machining. Fracture tests were successfully completed using a mechanical testing machine for micro-sized specimens at room temperature. The fracture toughness (KQ) values obtained were in the range 1.4–7 MPam1/2. Fracture surface observations indicate that these variations are attributable to differences in local lamellar orientations ahead of the notch. These fracture toughness values are also lower than those having been previously reported in conventional samples. This may be due the absence of significant extrinsic toughening mechanisms in these micro-sized specimens. Fracture mechanisms of these alloys are also considered on the micrometer scale. The results obtained in this investigation give important and fundamental information on the development of TiAl based alloys with high fracture toughness.

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Structural Micro-Layered Ceramics with Surfaces under Tension and Compression with Increasing Apparent Fracture Toughness

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.336-338.2564 ◽

2007 ◽

Vol 336-338 ◽

pp. 2564-2568 ◽

Cited By ~ 3

Author(s):

Jakob Kübler ◽

Gurdial Blugan ◽

Hans Jelitto ◽

Gerold A. Schneider ◽

Richard Dobedoe

Keyword(s):

Fracture Toughness ◽

Testing Machine ◽

High Fracture Toughness ◽

High Fracture ◽

Notched Specimens ◽

Apparent Fracture Toughness ◽

Tension And Compression ◽

Different Depths ◽

Layered Ceramics ◽

Stiff Testing Machine

Two different designs of high fracture toughness micro-laminate ceramics were produced containing 50 μm thick Si3N4 layers and 100 μm thick Si3N4 + TiN layers. The first design with external tensile layers had a predicted maximum apparent fracture toughness of 10.5 MPa m1/2. The second design with external compressive layers had a predicted maximum apparent fracture toughness of 18.0 MPa m1/2. The fracture toughness of these micro-laminates was tested by the SEVNB method. A stiff testing machine was used to measure the R-curve behavior by observing crack growth in single notched specimens. A soft testing machine was used to measure the R-curve behavior using several specimens with notches at different depths.

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Influence of NbC-Addition on Mechanical Properties of WC-Co

Materials Science Forum ◽

10.4028/www.scientific.net/msf.498-499.363 ◽

2005 ◽

Vol 498-499 ◽

pp. 363-368 ◽

Cited By ~ 1

Author(s):

Wilson Acchar ◽

Harim Revoredo de Macedo

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Niobium Carbide ◽

Testing Machine ◽

High Hardness ◽

Inert Atmosphere ◽

High Fracture Toughness ◽

High Wear Resistance ◽

High Fracture ◽

First Results

Cemented carbides have been intensively used as cutting tool through their high hardness, high fracture toughness and high wear resistance. A considerable amount of works has been developed in order to improve the mechanical properties of alternate cemented carbide systems. This work has the purpose to reports the first results obtained to WC-Co reinforced with 5 wt.% NbC. The mixture of powders was hot-pressed at 1250 °C in a inert atmosphere. Hardness and fracture toughness were carried out in a Vickers hardness testing machine. The results have showed that the addition of niobium carbide improves the hardness of tungsten carbide and inhibits the WCgrain growth.

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Susceptibility artifacts induced by crowns of different materials with prepared teeth and titanium implants in magnetic resonance imaging

Scientific Reports ◽

10.1038/s41598-021-03962-w ◽

2022 ◽

Vol 12 (1) ◽

Author(s):

Xiaomeng Gao ◽

Qianbing Wan ◽

Qingping Gao

Keyword(s):

Precious Metal ◽

Titanium Implants ◽

Zirconia Ceramic ◽

Signal Loss ◽

Susceptibility Artifacts ◽

Metal Ceramic ◽

Zirconia Crowns ◽

Artifacts Reduction ◽

Ceramic Crowns ◽

Tooth Preparation

AbstractThis study aimed to investigate the artifacts induced by crowns composed of different materials with prepared teeth and titanium implants. Resin, metal-ceramic, ceramic and zirconia crowns were fabricated and placed onto the prepared teeth on a human cadaver head or titanium implants with prosthesis abutments on a dry human mandible. The samples were scanned on a 1.5 T MRI apparatus, and artifact areas were defined as the signal intensity and signal loss adjacent to the prosthesis and measured by a threshold tool with ImageJ2x. Data were analyzed using SPSS 22.0. Resin, ceramic, zirconia, and precious metal-ceramic crowns barely produced artifacts on the cadaver skull (p > 0.999). By contrast, pure Ti and nonprecious metal-ceramic crowns created significant artifacts (p < 0.001). The average artifacts reduction of double Au-Pt and Ag-Pd metal-ceramic crowns combined with titanium implants and abutments was 79.49 mm2 (p < 0.001) and 74.17 mm2 (p < 0.001) respectively, while artifact areas were increased in double Co-Cr and Ni–Cr metal-ceramic crowns by 150.10 mm2 (p < 0.001) and 175.50 mm2 (p < 0.001) respectively. Zirconia, ceramic and precious metal-ceramic crowns induce less MRI artifacts after tooth preparation while precious metal-ceramic crowns alleviate artifacts in combination with titanium implants.

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KAISER ALUMINUM ALLOY 7050

Alloy Digest ◽

10.31399/asm.ad.al0366 ◽

2000 ◽

Vol 49 (1) ◽

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Tensile Strength ◽

Aluminum Alloy ◽

Heat Treating ◽

High Fracture Toughness ◽

High Fracture ◽

Kaiser Aluminum ◽

Structural Parts ◽

Very High

Abstract Kaiser Aluminum Alloy 7050 has very high mechanical properties including tensile strength, high fracture toughness, and a high resistance to exfoliation and stress-corrosion cracking. The alloy is typically used in aircraft structural parts. This datasheet provides information on composition, physical properties, hardness, tensile properties, and shear strength as well as fracture toughness and fatigue. It also includes information on forming, heat treating, machining, and joining. Filing Code: AL-366. Producer or source: Tennalum, A Division of Kaiser Aluminum.

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FERRIUM M54

Alloy Digest ◽

10.31399/asm.ad.sa0822 ◽

2018 ◽

Vol 67 (9) ◽

Keyword(s):

Fracture Toughness ◽

Stress Corrosion ◽

Stress Corrosion Cracking ◽

High Resistance ◽

High Strength ◽

Cost Effective ◽

High Fracture Toughness ◽

High Fracture ◽

Structural Applications ◽

Resistance To Stress

Abstract Ferrium M54 was designed to create a cost-effective, ultra high-strength, high-fracture toughness material with a high resistance to stress-corrosion cracking for use in structural applications. This datasheet provides information on composition, hardness, and tensile properties as well asfatigue. Filing Code: SA-822. Producer or source: QuesTek Innovations, LLC.

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Fracture of Soft Elastic Foam

Journal of Applied Mechanics ◽

10.1115/1.4032050 ◽

2015 ◽

Vol 83 (3) ◽

Cited By ~ 6

Author(s):

Zhuo Ma ◽

Xiangchao Feng ◽

Wei Hong

Keyword(s):

Fracture Toughness ◽

Fracture Energy ◽

Cell Walls ◽

Scaling Law ◽

Phase Field Model ◽

Base Material ◽

Network Connectivity ◽

High Fracture Toughness ◽

High Fracture ◽

Order Of Magnitude

Consisting of stretchable and flexible cell walls or ligaments, soft elastic foams exhibit extremely high fracture toughness. Using the analogy between the cellular structure and the network structure of rubbery polymers, this paper proposes a scaling law for the fracture energy of soft elastic foam. To verify the scaling law, a phase-field model for the fracture processes in soft elastic structures is developed. The numerical simulations in two-dimensional foam structures of various unit-cell geometries have all achieved good agreement with the scaling law. In addition, the dependences of the macroscopic fracture energy on geometric parameters such as the network connectivity and spatial orientation have also been revealed by the numerical results. To further enhance the fracture toughness, a type of soft foam structures with nonstraight ligaments or folded cell walls has been proposed and its performance studied numerically. Simulations have shown that an effective fracture energy one order of magnitude higher than the base material can be reached by using the soft foam structure.

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Comparative Evaluation of Fracture Resistance of Endodontically Treated Teeth Restored with Resin Fiber Post and Stainless Steel Post: An In Vitro Study

Dental Journal of Advance Studies ◽

10.1055/s-0038-1672019 ◽

2015 ◽

Vol 03 (02) ◽

pp. 080-084

Author(s):

Vijay Singh ◽

Poonam Bogra ◽

Saurabh Gupta ◽

Navneet Kukreja ◽

Neha Gupta

Keyword(s):

Stainless Steel ◽

Fracture Resistance ◽

Testing Machine ◽

Compressive Force ◽

Control Group ◽

Fiber Post ◽

Endodontically Treated Teeth ◽

Group I ◽

Significant Difference

AbstractFracture resistance of endodontically treated teeth restored with post. Aims: This study aims to compare the fracture resistance of endodontically treated teeth restored with resin fiber and stainless steel post. Commercially available prefabricated resin fiber post(Dentsply Maillefer Easy Post), prefabricated stainless steel post(Coltene/Whaledent Parapost) were used. Methods and Material: Forty five maxillary central incisors were obturated and divided into 3 groups: Control Group (Group I) without any post (n = 15), Resin Fiber Post Group (Group II) (n = 15) and Stainless Steel Post Group (Group III) (n = 15). In all Groups except control group, post space was prepared; a post was cemented, and a core build-up was provided. All the specimens were subjected to compressive force under a universal testing machine until fracture. Statistical analysis used: The results were analyzed using the variable analysis test (ANOVA). Results: One-way analysis of variance revealed significant difference among test groups. The control group demonstrated highest fracture resistance (925.2183 N), followed by the resin fiber post group (486.7265 N) and stainless steel post group (423.539N). Conclusions: Teeth restored with resin fiber post showed higher fracture resistance values than prefabricated stainless steel post.

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Tough metal-ceramic composites with multifunctional nacre-like architecture

Scientific Reports ◽

10.1038/s41598-021-81068-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Erik Poloni ◽

Florian Bouville ◽

Christopher H. Dreimol ◽

Tobias P. Niebel ◽

Thomas Weber ◽

...

Keyword(s):

Fracture Toughness ◽

Sol Gel ◽

Ceramic Composites ◽

High Fracture Toughness ◽

Processing Route ◽

High Fracture ◽

Metal Ceramic ◽

Attractive Option ◽

Brick And Mortar ◽

Robotic Applications

AbstractThe brick-and-mortar architecture of biological nacre has inspired the development of synthetic composites with enhanced fracture toughness and multiple functionalities. While the use of metals as the “mortar” phase is an attractive option to maximize fracture toughness of bulk composites, non-mechanical functionalities potentially enabled by the presence of a metal in the structure remain relatively limited and unexplored. Using iron as the mortar phase, we develop and investigate nacre-like composites with high fracture toughness and stiffness combined with unique magnetic, electrical and thermal functionalities. Such metal-ceramic composites are prepared through the sol–gel deposition of iron-based coatings on alumina platelets and the magnetically-driven assembly of the pre-coated platelets into nacre-like architectures, followed by pressure-assisted densification at 1450 °C. With the help of state-of-the-art characterization techniques, we show that this processing route leads to lightweight inorganic structures that display outstanding fracture resistance, show noticeable magnetization and are amenable to fast induction heating. Materials with this set of properties might find use in transport, aerospace and robotic applications that require weight minimization combined with magnetic, electrical or thermal functionalities.

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Interfacial Fracture Toughness Comparison of Three Indirect Resin Composites to Dentin and Polyether Ether Ketone Polymer

European Journal of Dentistry ◽

10.1055/s-0040-1713309 ◽

2020 ◽

Vol 14 (03) ◽

pp. 456-461

Author(s):

Rayhaneh Khalesi ◽

Mahdi Abbasi ◽

Zahra Shahidi ◽

Masoumeh Hasani Tabatabaei ◽

Zohreh Moradi

Keyword(s):

Fracture Toughness ◽

Bond Strength ◽

Testing Machine ◽

Composite Resins ◽

High Wear Resistance ◽

Luting Cements ◽

Anterior Teeth ◽

Polyether Ether Ketone ◽

Ether Ketone

Abstract Objectives Advances in laboratory composites and their high wear resistance and fracture toughness have resulted in their growing popularity and increasing use for dental restorations. This study sought to assess the fracture toughness of three indirect composites bonded to dental substrate and polyether ether ketone (PEEK) polymer. Materials and Methods This in vitro study was conducted on two groups of dental and polymer substrates. Each substrate was bonded to three indirect composite resins. Sixty blocks (3 × 3 × 12 mm) were made of sound bovine anterior teeth and PEEK polymer. Sixty blocks (3 × 3 × 12 mm) were fabricated of CRIOS (Coltene, Germany), high impact polymer composite (HIPC; Bredent, Germany), and GRADIA (Indirect; GC, Japan) composite resins. Composites were bonded to dentin using Panavia F 2.0 (Kuraray, Japan). For bonding to PEEK, Combo.lign (Bredent) and Visio.Link (Bredent) luting cements were used. In all samples, a single-edge notch was created by a no. 11 surgical blade at the interface. The samples were subjected to 3,500 thermal cycles, and their fracture toughness was measured in a universal testing machine (Zwick/Roell, Germany) by application of four-point flexural load. Statistical Analysis Data were analyzed using one-way analysis of variance, Kruskal–Wallis. Results The fracture toughness of CRIOS–PEEK interface was significantly higher than HIPC–PEEK. The fracture toughness of GRADIA–PEEK was not significantly different from that of HIPC and CRIOS. The fracture toughness of GRADIA–dentin was significantly higher than HIPC–dentin. Conclusion Considering the limitations of this study, GRADIA has the highest bond strength to dentin, while CRIOS shows the highest bond strength to PEEK.

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