Mechanical Behavior of Ceramic Monolithic Systems With Different Thicknesses

2019 ◽  
Vol 44 (5) ◽  
pp. E244-E253
Author(s):  
D Longhini ◽  
COM Rocha ◽  
LT de Oliveira ◽  
NG Olenscki ◽  
EA Bonfante ◽  
...  

SUMMARY Objectives: This study assessed the fully stabilized zirconia (FSZ) Prettau Anterior, the partially stabilized zirconia (PSZ) Prettau, and the lithium disilicate IPS e.max CAD (LD) through microstructural and mechanical characterization and effect of thickness on fracture load of the ceramics. Methods and Materials: Disk-shaped specimens (12 mm diameter and 1.2 mm thickness) were prepared for biaxial flexural strength (BFS) and Weibull statistics (n=30). For the fracture load static test (FLST) and Weibull statistics (n=30), disk-shaped specimens 12 mm in diameter and thicknesses of 0.5 mm, 1 mm, and 1.5 mm were cemented on an epoxy-resin substrate. Results: BFS (MPa) results were PSZ: 683.0 ± 70.23; FSZ: 438.6 ± 64.1; and LD: 248.6 ± 37.3. One-way analysis of variance (ANOVA) for BFS was significant (p<0.001), and the Tukey post hoc test showed differences among all ceramics. There was difference in characteristic strength, but there was no difference in Weibull modulus. Two-way ANOVA for FLST was significant for ceramic (p<0001), thickness (p<0001), and interaction (p<0001). There was no difference among all ceramics at the 0.5 mm thickness. PSZ had higher values for the 1.0 mm and 1.5 mm thicknesses. LD of 1.5 mm thickness exhibited a higher FLST than FSZ. Conclusions: PSZ had the highest BFS, but when cemented on a substrate, all ceramics with 0.5 mm thickness behaved similarly. Despite the lower BFS, LD had a fracture load similar or superior to FSZ when cemented on a substrate.

2019 ◽  
Vol 22 (1) ◽  
pp. Process
Author(s):  
Shereen Ahmed Nossair ◽  
Tarek Salah ◽  
Kamal Khaled Ebeid

Objective: This study was designed to evaluate the biaxial flexural strength (BFS) of different types of unshaded and shaded monolithic zirconia. Material and Methods: 120 monolithic zirconia ceramic discs were fabricated. They were divided into twelve groups (n=10), Group 1; Bruxzir unshaded, Group 2; Bruxzir shaded A2, Group 3; Bruxzir anterior white, Group 4; Bruxzir anterior shade A2, Group 5; Prettau unshaded, Group 6; Prettau shaded with A2 coloring liquid, Group 7; Prettau anterior white, Group 8; Prettau anterior shaded with A2 coloring liquid, Group 9; Katana HT white, Group 10; Katana HT shade A2, Group 11; Katana ST white, Group 12; Katana ST shade A2. All discs were milled using a dental milling machine, and had final dimensions after sintering of 15 mm diameter and 1 mm thickness. BFS was tested using piston on three ball technique. Results:  One-way ANOVA revealed significant differences among the 12 groups. Tukey post-hoc tests revealed no significant differences between the groups 3, 4, ,7 ,8 11, and 12. However, they all had BFS values that are significantly lower than all other groups. Group 2 showed statistically significant higher BFS values when compared to group 3,4, 7, 8, 11, and 12 while it showed statistically significant lower values when compared to groups 1, 5, 6, 9, and 10. Conclusion: Increase in the yttria content in zirconia led to a decrease in its BFS. Shading of zirconia did not have a significant effect on the final strength of zirconia. KeywordsDental ceramics; Dental esthetics; Flexural strength; Shaded zirconia. 


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Niwut Juntavee ◽  
Apa Juntavee ◽  
Sirintana Phetpanompond

Introduction. High-translucence ceramics have been used increasingly. This study evaluated the biaxial flexural strength of different ceramics as a result of varying thicknesses. Materials and Methods. Circular discs with varied thickness of 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, and 2.0 mm were prepared from high-translucence yttria-partially stabilized zirconia (HTY-PSZ); Bruxzir® Anterior (Bc), and zirconia-reinforced lithium silicate (ZLS) including Celtra® DUO (Cc) and VITA Suprinity® (Vc) (n = 15 discs/group). Biaxial flexural strength (σ) was evaluated utilizing piston-on-three-balls in a testing machine at a speed of 0.5 mm/min. A scanning electron microscope (SEM) was used to determine the microscopic structure. ANOVA and multiple comparisons were analyzed for significant differences (a = 0.05). Results. The mean ± sd value of σ (MPa) for thickness 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, and 2.0 mm was 672.66 ± 107.54, 655.93 ± 93.98, 589.01 ± 63.63, 624.89 ± 87.08, 618.82 ± 83.36, 672.64 ± 84.61, 659.81 ± 122.89, 632.79 ± 92.54, and 657.86 ± 73.17, for Bc; 477.64 ± 88.23, 496.39 ± 86.36, 461.56 ± 57.00, 450.26 ± 86.60, 468.28 ± 83.65, 472.45 ± 53.63, 453.05 ± 72.50, 462.67 ± 47.57, and 535.28 ± 84.33, for Cc; and 500.97 ± 76.36, 506.70 ± 87.76, 557.82 ± 62.78, 543.76 ± 87.29, 507.53 ± 86.09, 502.46 ± 64.75, 557.70 ± 80.91, 527.04 ± 80.78, and 499.88 ± 57.35, for Vc. A significant difference in flexural strength was indicated among groups ( p < 0.05 ). Bc was significantly stronger than Cc and Vc ( p < 0.05 ). Varying thickness did not have a significant influence on strength ( p > 0.05 ). SEM revealed a tight arrangement of crystals for Bc and needle-like crystals diffusing in glass for Vc and Cc. Conclusion. Flexural strength of ceramics varied among types, but each retained strength equitably with varying thickness. HTY-PSZ was stronger than ZLS, but each was equally strong for thickness in the range of 0.4–2.0 mm.


2019 ◽  
Vol 44 (5) ◽  
pp. E254-E262 ◽  
Author(s):  
EB Benalcázar Jalkh ◽  
CM Machado ◽  
M Gianinni ◽  
I Beltramini ◽  
MMT Piza ◽  
...  

SUMMARY New resin-based restorative materials have been developed, such as computer-aided design/computer-aided manufacturing (CAD/CAM) and bulk-fill composites, as an alternative to traditional layering techniques. This study evaluated the biaxial flexural strength (BFS) before and after thermocycling of five different resin composites: one hybrid resin/ceramic CAD/CAM indirect material, Lava Ultimate CAD-CAM Restorative (LU, 3M Oral Care); a conventional composite, Filtek Z350 XT (Z350, 3M Oral Care); two bulk-fill composites, Tetric N-Ceram Bulk Fill (TBF, Ivoclar Vivadent) and Filtek Bulk Fill (FBF, 3M Oral Care); and one bulk-fill flow resin composite, Filtek Bulk Fill Flow (FBFF, 3M Oral Care). Three hundred disc-shaped specimens (6.5 mm in diameter and 0.5 mm thick) were fabricated and divided into five groups (n=30 for each composite and condition). The BFS test was performed in a universal testing machine at a crosshead speed of 0.5 mm/min immediately (i, 24 hours) and after thermocycling (a, 500 thermal cycles of 5°C to 55°C with a 30-second dwell time). The Weibull modulus (m) and characteristic stress (η) were calculated, and a contour plot was used (m vs η) to detect differences between groups (95% two-sided confidence intervals). Significantly higher characteristic stress was observed for LUi (286.6 MPa) and Z350i (248.8 MPa) compared to the bulk-fill groups (FBFi=187.9 MPa, FBFFi=175.9 MPa, TBFi=149.9 MPa), with no differences between LUi and Z350i. Thermocycling significantly decreased the characteristic stress of all groups with the highest values observed for LUa (186.7 MPa) and Z350a (188.9 MPa) and the lowest for FBFFa (90.3 MPa). Intermediate values were observed for FBFa (151.6 MPa) and TBFa (122.8 MPa). The Weibull modulus decreased only for FBFa compared to FBFi. Composition and thermocycling significantly influenced the biaxial flexural strength of resin composite materials.


2012 ◽  
Vol 18 (5) ◽  
pp. 805-812 ◽  
Author(s):  
Gye-Jeong Oh ◽  
Kwangmin Lee ◽  
Doh-Jae Lee ◽  
Hyun-Pil Lim ◽  
Kwi-Dug Yun ◽  
...  

2019 ◽  
Vol 30 (2) ◽  
pp. 164-170 ◽  
Author(s):  
Fernanda P. Silva ◽  
Ana L. R. Vilela ◽  
Matheus M. G. Almeida ◽  
André R. F. Oliveira ◽  
Luís H. A. Raposo ◽  
...  

Abstract This study evaluated the effect of different finishing-polishing protocols on surface roughness, gloss, morphology and biaxial flexural strength of pressable fluorapatite glass ceramic. Thirty ceramic discs (12x1 mm) were produced and divided into five groups (n=6): CT: control (glaze); DA: fine grit diamond bur; DG: DA + new glaze layer; DP: DA + felt disk with fine grit diamond paste; DK: DA+ sequential polishing with silicon abrasive instruments, goat hair brush and cotton wheel. The specimens were analyzed for surface roughness (Ra) under profilometry and atomic force microscopy (AFM). Gloss was measured with spectrophotometry and micromorphology with scanning electron microscopy (SEM). Flexural strength was assessed by biaxial flexural strength test. Data were analyzed using one-way ANOVA and Tukey’s post hoc test (a=0.05). DK showed the lowest surface roughness values and DA presented the highest in the perfilometer analysis. No significant differences were observed in the AFM for the CT, DG and DK groups, which presented the lower surface roughness; DA and DP had the higher Ra values. The DA, DP and CT showed the lowest surface gloss values, and the reflectance was significantly different from those observed for DK and DG groups. SEM analysis revealed the smoothest surface for DK group, followed by DG and CT groups; DA and DP groups exhibited variable degrees of surface irregularities. No significant differences were observed among groups for the biaxial flexural strength. The polishing protocol used in DK group can be a good alternative for chairside finishing of adjusted pressable fluorapatite glass ceramic surfaces.


2018 ◽  
Vol 34 (8) ◽  
pp. 1199-1210 ◽  
Author(s):  
Tomofumi Sawada ◽  
Christine Schille ◽  
Verena Wagner ◽  
Sebastian Spintzyk ◽  
Ernst Schweizer ◽  
...  

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 244
Author(s):  
Reem AlMutairi ◽  
Hend AlNahedh ◽  
Ahmed Maawadh ◽  
Ahmed Elhejazi

In this study, the biaxial flexural strength (BFS) and fractography of high/ultra-translucent monolithic zirconia ceramics subjected to different mechanical surface pretreatments were evaluated. A total of 108 disc-shaped samples (12 mm diameter, 1.2 mm thickness) of three zirconia materials (5Y-ZP KATANA Zirconia UTML (ML), 3Y-TZP DD Bio ZX2 (DB), and 5Y-ZP DD cube X2 (DC)) were used. The BFS was investigated after subjecting the samples to surface treatment using air abrasion particles of two types (aluminum oxide or glass microbeads). The data were analyzed using two-way analysis of variance, followed by Scheffe’s post hoc test for multiple comparisons. The mean ± standard deviation BFS for DB was highest after treatment with 50 µm Al2O3 (1626.05 ± 31.9 MPa), with lower values being observed following treatment with 50 µm glass microbeads (1399.53 ± 24.2 MPa) and in the control sample (1198.51 ± 21.1 MPa). The mean ± standard deviation (SD) BFSs for DC and ML were the highest in the control groups. Surface air abrasion with 50 µm Al2O3 particles and 2 bar pressure is recommended for 3Y-TZP translucent zirconia, while no abrasion of 5Y-ZP translucent zirconia ceramic.


2019 ◽  
Vol 44 (6) ◽  
pp. 615-624
Author(s):  
A Sundh ◽  
W Kou ◽  
G Sjögren

SUMMARYObjectives:To evaluate the effects of surface treatment, specimen thickness, and aging on the biaxial flexural strength (BFS) of two types of yttria-stabilized, tetragonal zirconia polycrystal (Y-TZP) ceramics.Methods and Materials:Disc-shaped specimens, 0.4 and 1.3 mm thick, made from hot isostatic pressed (Denzir) and non–hot isostatic pressed (ZirPlus) Y-TZP, were sandblasted, heat treated, and autoclaved. The surface topography was assessed in accordance with European Standard 623-624:2004 and the BFS tests in accordance with International Organization for Standardization Standard 6872:2008. For statistical analyses, one-way Shapiro-Wilk test, analysis of variance (post hoc: least significant differences), Mann-Whitney U-test, and Pearson correlation tests (p&lt;0.05) were used.Results:As delivered, the BFS of the 0.4-mm ZirPlus was &gt;1.3-mm ZirPlus (p&lt;0.01), and the BFS of the 0.4-mm Denzir was &gt;1.3-mm Denzir (p&lt;0.001). Sandblasting with 0.2 MPa reduced the BFS of the ZirPlus and Denzir discs (p&lt;0.01), whereas sandblasting with 0.6 MPa increased the BFS of the 0.4-mm Denzir (p&lt;0.001) and reduced the BFS of the 0.4-mm ZirPlus (p&lt;0.05). Heat treatment significantly reduced the BFS of all the groups except for the 0.6 MPa sandblasted 0.4-mm ZirPlus. Autoclaving reduced the BFS of the as-delivered ZirPlus and Denzir specimens (p&lt;0.001), whereas autoclaving the 0.6 MPa sandblasted and heat-treated specimens had no effect (p&gt;0.05) on the BFS. The 0.6 MPa sandblasted, heat-treated, and autoclaved 0.4-mm Denzir exhibited higher BFS than the 0.6 MPa sandblasted, heat-treated, and autoclaved 0.4-mm ZirPlus (p&lt;0.05).Conclusions:Thickness and surface treatment of Y-TZP–based ceramics should be considered since those factors could influence the BFS of the material.


2012 ◽  
Vol 3 (2) ◽  
pp. 131-135 ◽  
Author(s):  
Tavakkol Omid ◽  
Mortazavi Moghaddam Venus ◽  
Sharafeddin Farahnaz ◽  
Alavi Ali Asghar

ABSTRACT The aim of this study was to determine experimentally maximum fracture load of fiber-reinforced composite with different span lengths and to determine the effect of glass fiber on this parameter. Materials and methods Six fiber-reinforced groups (n = 10) were made with three different lengths (10, 15, 20 mm) with or without glass fiber in split mold. The specimens were early cured and then post-cured with a labolite unit, then specimens were subjected to three-point flexural test by a universal testing machine. Data were analyzed with ANOVA and LSD post-hoc test (p < 0.05). Results Maximum fracture load of specimens increased with decreasing lengths (p < 0.001) and fiber-containing group showed significantly higher fracture load than fiberless groups (p < 0.001). Conclusion It was concluded that by increasing the span length, the maximum fracture load values (N) decreased incorporation of fiber results in higher fracture strength values. How to cite this article Omid T, Venus MM, Farahnaz S, Asghar AA. Effect of Glass Fiber Length on Flexural Strength of Fiber-reinforced Composite Resin. World J Dent 2012;3(2):131-135.


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