Influence of CAD-CAM milling on the flexural strength of Y-TZP dental ceramics

In this study, the physical properties of a custom block manufactured using a self-polymerizing resin (Custom-block), the commercially available CAD/CAM PMMA disk (PMMA-disk), and a heat-polymerizing resin (Conventional PMMA) were evaluated via three different tests. The Custom-block was polymerized by pouring the self-polymerizing resin into a special tray, and Conventional PMMA was polymerized with a heat-curing method, according to the manufacturer’s recommended procedure. The specimens of each group were subjected to three-point bending, water sorption and solubility, and staining tests. The results showed that the materials met the requirements of the ISO standards in all tests, except for the staining tests. The highest flexural strength was exhibited by the PMMA-disk, followed by the Custom-block and the Conventional PMMA, and a significant difference was observed in the flexural strengths of all the materials (p < 0.001). The Custom-block showed a significantly higher flexural modulus and water solubility. The water sorption and discoloration of the Custom-block were significantly higher than those of the PMMA-disk, but not significantly different from those of the Conventional PMMA. In conclusion, the mechanical properties of the three materials differed depending on the manufacturing method, which considerably affected their flexural strength, flexural modulus, water sorption and solubility, and discoloration.

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Chairside CAD/CAM materials. Part 2: Flexural strength testing

Dental Materials ◽

10.1016/j.dental.2016.10.008 ◽

2017 ◽

Vol 33 (1) ◽

pp. 99-109 ◽

Cited By ~ 105

Author(s):

Michael Wendler ◽

Renan Belli ◽

Anselm Petschelt ◽

Daniel Mevec ◽

Walter Harrer ◽

...

Keyword(s):

Flexural Strength ◽

Strength Testing ◽

Cad Cam

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A fogászati kerámiaanyagok fejlődésének történeti áttekintése

Kaleidoscope History ◽

10.17107/kh.2021.22.284-293 ◽

2021 ◽

Vol 11 (22) ◽

pp. 284-293

Author(s):

József Saláta

Keyword(s):

Thermal Expansion ◽

18Th Century ◽

Ceramic Materials ◽

Dental Ceramics ◽

New Techniques ◽

Casting Alloys ◽

Burnt Clay ◽

Cad Cam ◽

Increasing Demand ◽

Dental Casting Alloys

Initially, ceramics - mostly burnt clay - were used to manufacture container pottery. The first porcelain objects reached Europe out of China in the Medieval Ages. The technique of their manufacturing was a mystery for many hundred years, yet Germans succeeded first to produce fine European porcelain at the beginning of the 18th century. Its elegance and hardness woke the dentists’ interest too thus Frenchmen created the first porcelain dentures in the second half of the 18th century. Since then, there has been an increasing demand for esthetic fixed implant dentures instead of removable ones. The development of ceramic materials resulted in better mechanical and optical properties, thus the first fixed porcelain inlays and jacket crowns were introduced already in 1889. The addition of leucite filler crystals to porcelain in the 20th century increased the thermal expansion of the ceramic. It could be fired on common dental casting alloys, so the first porcelain-fused-to-metal (PFM) crown was created in 1962. Several new techniques were developed from the middle of the 1980s to the end of the 1990s to deal with initial shrinkage and achieve better properties. Beyond casting, pressing, and CAD/CAM technology, additive manufacturing opened new perspectives in dentistry several years ago in processing dental ceramics.

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Flexural strength of CAD-CAM and conventional interim resin materials with a surface sealant

Journal of Prosthetic Dentistry ◽

10.1016/j.prosdent.2020.09.004 ◽

2020 ◽

Vol 124 (6) ◽

pp. 800.e1-800.e7

Author(s):

Gülce Çakmak ◽

Hakan Yilmaz ◽

Özge Aydoğ ◽

Burak Yilmaz

Keyword(s):

Flexural Strength ◽

Cad Cam ◽

Surface Sealant

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Effect of the bur grit size on the flexural strength of a glass-ceramic

Cerâmica ◽

10.1590/0366-69132016623621988 ◽

2016 ◽

Vol 62 (362) ◽

pp. 121-127 ◽

Cited By ~ 1

Author(s):

P. P. Kist ◽

I. L. Aurélio ◽

M. Amaral ◽

L. G. May

Keyword(s):

Surface Roughness ◽

Flexural Strength ◽

Glass Ceramic ◽

Glass Ceramics ◽

Internal Surface ◽

Grit Size ◽

Diamond Grit ◽

Cad Cam ◽

Negative Effect ◽

Ceramic Blocks

Abstract The purpose of the present study was to determine the biaxial flexural strength (BFS) of a CAD/CAM leucite reinforced glass-ceramic ground by diamond burs of different grit sizes and the influence of surface roughness on the BFS. For this, 104 plates were obtained from CAD/CAM ceramic blocks and divided into 4 groups (n = 26), according to bur grit size: extra-fine, fine, medium and coarse. Roughness parameters (Ra, RyMax) were measured, and plates were kept dry for 7 days. The flexural test was carried out and BFS was calculated. Ra, RyMax and BFS data were subjected to analysis of variance and post-hoc test. Weibull analysis was used to compare characteristic strength and Weibull modulus. Regression analysis was performed for BFS vs. Ra and RyMax. When burs with coarse grit were used, higher surface roughness values were found, causing a negative effect on the ceramic BFS (117 MPa for extra-fine, and 83 MPa for coarse). Correlation (r) between surface roughness and BFS was 0.78 for RyMax and 0.73 for Ra. Increases in diamond grit size have a significant negative effect on the BFS of leucite-reinforced glass-ceramics, suggesting that grinding of sintered glass-ceramic should be performed using burs with the finest grit possible in order to minimize internal surface flaws and maximize flexural strength.

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Flexural strength and reliability of CAD/CAM materials for dental applications

Dental Materials ◽

10.1016/j.dental.2018.08.020 ◽

2018 ◽

Vol 34 ◽

pp. e9

Author(s):

M.A. Basílio ◽

E. Lima ◽

A.B. Soares ◽

P.F. Cesar

Keyword(s):

Flexural Strength ◽

Cad Cam ◽

Dental Applications

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Biaxial flexural strength and Weilbull characteristics of adhesively luted hybrid and reinforced CAD/CAM materials to dentin: effect of self-etching ceramic primer versus hydrofluoric acid etching

Journal of Adhesion Science and Technology ◽

10.1080/01694243.2019.1710991 ◽

2020 ◽

Vol 34 (12) ◽

pp. 1253-1268

Author(s):

João Paulo Mendes Tribst ◽

Amanda Maria de Oliveira Dal Piva ◽

Gabriel Cirone Lopes ◽

Alexandre Luiz Souto Borges ◽

Marco Antonio Bottino ◽

...

Keyword(s):

Flexural Strength ◽

Hydrofluoric Acid ◽

Acid Etching ◽

Biaxial Flexural Strength ◽

Cad Cam

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Wear Characteristics of Dental Ceramic CAD/CAM Materials Opposing Various Dental Composite Resins

Materials ◽

10.3390/ma12111839 ◽

2019 ◽

Vol 12 (11) ◽

pp. 1839 ◽

Cited By ~ 2

Author(s):

Bora Gwon ◽

Eun-Bin Bae ◽

Jin-Ju Lee ◽

Won-Tak Cho ◽

Hyun-Young Bae ◽

...

Keyword(s):

Weight Loss ◽

Composite Resin ◽

Lithium Disilicate ◽

Composite Resins ◽

Dental Composite ◽

Dental Ceramics ◽

Wear Properties ◽

Dental Ceramic ◽

Dental Composite Resins ◽

Cad Cam

The aim of this study was to evaluate the wear properties of opposed dental ceramic restorative CAD/CAM materials and several posterior direct restorative composite resins. Three kinds of dental ceramics CAD/CAM materials (monolithic zirconia, lithium disilicate, leucite) and four dental composite resins—that is, MI Gracefil, Gradia Direct P, Estelite Σ Quick, and Filtek Supreme Ultra—were used in this study. For each of the 12 groups (three ceramics × four composite resins), five each of a canine-shaped ceramic specimen and a cuboidal shape opposing composite resin were prepared. All of the specimens were tested in a thermomechanical loading machine (50 N, 100,000 cycles, 5/55 °C). Wear losses of ceramic specimens and composite resin specimens were evaluated using a three-dimensional profiling system and an electronic scale, respectively. Statistical analyses were performed using the Kruskal–Wallis test and Mann–Whitney U test with Bonferroni’s correction. Zirconia showed significantly less volumetric loss than lithium disilicate or leucite regardless of composite resin type (p > 0.05/3 = 0.017), and that Estelite Σ Quick showed significantly more weight loss than Filtek Supreme Ultra, MI Gracefil, or Gradia Direct P regardless of ceramic type (p > 0.05/6 = 0.083). Zirconia showed less volumetric loss than lithium disilicate or leucite. Some composite resins opposing ceramics showed considerable weight loss.

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Comparison of Fracture Strength and Fracture Modes of Zirconia Dental Ceramics Manufactured by Four Different CAD/CAM Systems

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.492.30 ◽

2011 ◽

Vol 492 ◽

pp. 30-34

Author(s):

Dan Wang ◽

Yuan Zhi Xu ◽

Cheng Lin Lu ◽

Qi Xiang Yang ◽

Dong Sheng Zhang ◽

...

Keyword(s):

Cyclic Loading ◽

Critical Load ◽

Fracture Strength ◽

Fracture Load ◽

Image Correlation ◽

Zirconia Ceramic ◽

Dental Ceramics ◽

High Fracture ◽

Fracture Modes ◽

Cad Cam

Four sorts of zirconia dental ceramic systems including Cercon smart, Lava, Porcera, and CEREC 3 were studied to analyze fracture mechanism of different CAD/CAM zirconia ceramic. In each system, 12 sectioned specimens were prepared, 6 specimens were taken as controlled group, 6 as experimental group. Quasi-statistic loading before and after cyclic loading was applied at the veneer surface of the specimen. Deformation and crack initiation were monitored with camera in order to carry out digital image correlation (DIC) analysis. The results showed that median cracks were observed under the yielding zone. Specimens fractured along the core/veneer interface with the crack growth. No cone crack was confirmed and fracture only existed in veneer layer. After cyclic loading there were no significant differences for the four ceramic systems in terms of the critical load, while significant differences existed in terms of the fracture load. Both critical load and fracture load were lowered after cyclic loading. After cycling loading, the 4 tested zirconia CAD/CAM ceramic possess high fracture strength to meet the requirement for oral functions. The fracture modes of the four zirconia ceramic systems indicate that the strength of the veneer should be enhanced.

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