Flexural Strength of Composite Based Provisional Crown Materials

Introduction: One of the important aspects of provisional restorations, especially in case of long-span edentulous situations, short-height pontics, extended treatment time and in patients with para-functional habits is their flexural strength. Maintaining the integrity of the provisional restorations throughout the course of treatments is highly valuable and important to have a predictable outcome. Objectives: To evaluate and compare the flexural strength of composite based provisional materials. Materials and Methods: Materials: Group 1, conventional bisacryl composite material (Protemp 4, 3M). Group 2, Computer Assisted Designing - Computer Assisted Milling (CAD-CAM) composite provisional material (CAD Temp). Method: Twenty identical specimens sized 25×2×2-mm were prepared from each material. A standard three-point bending test was conducted on the specimens with a universal testing machine at a 0.5 mm/min crosshead speed, and the flexural strength values were calculated (MPa) for each specimen. The flexural strength data were statistically analyzed using T-Test. Results: The measured mean flexural strength values (MPa) were as follow: group1 = 99.38 in comparison to group 2 = 92.06. There were statistically significant differences among the flexural strengths of tested materials (P < 0.05), The conventional group had significantly higher flexural strength than the CAD/CAM group (p < 0.05). Conclusion: Within the limitation of this study, the bisacryl composite resin (Protemp 4) provisional material has superior flexural strength than CAD/CAM composite material. Although many authors recommended the use of CAD/CAM provisional materials, this study prove that the material composition is as important as the material method of fabrication.

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Fracture Load of Metal, Zirconia and Polyetheretherketone Posterior CAD-CAM Milled Fixed Partial Denture Frameworks

Materials ◽

10.3390/ma14040959 ◽

2021 ◽

Vol 14 (4) ◽

pp. 959

Author(s):

Verónica Rodríguez ◽

Celia Tobar ◽

Carlos López-Suárez ◽

Jesús Peláez ◽

María J. Suárez

Keyword(s):

Computer Aided Design ◽

Testing Machine ◽

Fracture Load ◽

Fracture Pattern ◽

Bending Test ◽

Weibull Statistics ◽

Promising Alternative ◽

Computer Aided ◽

Cad Cam ◽

Group 2

The aim of this study was to investigate the load to fracture and fracture pattern of prosthetic frameworks for tooth-supported fixed partial dentures (FPDs) fabricated with different subtractive computer-aided design and computer-aided manufacturing (CAD-CAM) materials. Materials and Methods: Thirty standardized specimens with two abutments were fabricated to receive three-unit posterior FDP frameworks with an intermediate pontic. Specimens were randomly divided into three groups (n = 10 each) according to the material: group 1 (MM)—milled metal; group 2 (L)—zirconia; and group 3 (P)—Polyetheretherketone (PEEK). The specimens were thermo-cycled and subjected to a three-point bending test until fracture using a universal testing machine (cross-head speed: 1 mm/min). Axial compressive loads were applied at the central fossa of the pontics. Data analysis was made using one-way analysis of variance, Tamhane post hoc test, and Weibull statistics (α = 0.05). Results: Significant differences were observed among the groups for the fracture load (p < 0.0001). MM frameworks showed the highest fracture load values. The PEEK group registered higher fracture load values than zirconia samples. The Weibull statistics corroborated these results. The fracture pattern was different among the groups. Conclusions: Milled metal provided the highest fracture load values, followed by PEEK, and zirconia. However, all tested groups demonstrated clinically acceptable fracture load values higher than 1000 N. PEEK might be considered a promising alternative for posterior FPDs.

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Investigation of Mechanical Properties of Nano Sized Clay/LDH Particle as Hybrid Nano Composite Material

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.766-767.355 ◽

2015 ◽

Vol 766-767 ◽

pp. 355-361

Author(s):

S. Sivasaravanan ◽

V.K. Bupesh Raja ◽

S. Prabhu ◽

S. Dineshkumar ◽

Gokulaprasad

Keyword(s):

Composite Material ◽

Testing Machine ◽

Weight Ratio ◽

High Strength ◽

Sem Analysis ◽

Bending Test ◽

Flexural Property ◽

Weight Percentage ◽

Three Point Bending ◽

Sonication Technique

Usage of Hybrid nanocomposite materials provides a greater opportunity to replace the conventional materials due to their properties such as light weight and high strength to based on weight ratio. In this synergitic study, nanosized clay particle and layered double hydroxide particles are used. nanoclay and LDH particles were mixed on the bases of weight percentage (1wt% to 5wt%) by ultra sonication technique. The composite material was fabricated by one of the most common method known as hand lay-up technique. The composite materials was prepared in the form of plate with 4mm of thickness.The characterization of tensile and flexural property of the nanoclay, LDH and combination of both was analysis by tensile test using universal testing machine and three point bending test respectively. The tensile and three point bending test specimens were cut to size as per ASTM standard.The morphology of composite was studied using SEM analysis.

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Influence of time and hydration (ageing) on flexural strength of Yttrium stabilized Zirconia polycrystals (Y-TZP) fabricated with different CAD-CAM Systems

Pakistan Journal of Medical Sciences ◽

10.12669/pjms.37.3.3996 ◽

2021 ◽

Vol 37 (3) ◽

Author(s):

Khulud A Al Aali ◽

Saad Alresayes ◽

Aasem M Alhenaki ◽

Fahim Vohra ◽

Tariq Abduljabbar

Keyword(s):

Flexural Strength ◽

Testing Machine ◽

Control Group ◽

Stabilized Zirconia ◽

Cad Cam ◽

Group 3 ◽

Group 2 ◽

Cam Systems ◽

Ageing Duration ◽

Group 1

Objectives: To evaluate the effect of time and hydration (ageing) on flexural strength of yttrium-stabilized zirconia polycrystals (Y-TZP) zirconia fabricated from three different materials. Methods: This in-vitro study was performed from June to September 2019. Y-TZP bars, measuring 2 x 3 x 20 mm were prepared and sintered from three different materials, Group-1: LAVA™ Zirconia (3M™ ESPE, US) (control) Group-2: Vita In-Ceram YZ (VITA, Germany) and Group-3: Aadva™ Zirconia (Zr) (GC Advanced technologies Inc.). 30 zirconia bars per group were prepared using sectioning of blocks with isomet saw. Followed by sintering in furnaces for recommended temperature cycles. One side of bars were polished and beveled for flexural testing. Groups of specimens were divided into subgroups of 3 (n=10) based on the ageing (distilled water in the incubator at 37ºC) durations (48 Hrs and two and half years). Ten specimens in each material groups were not aged (controls). Samples were exposed to a static force in a three-point bend test using a universal instron-testing machine until fracture. Scanning electron microscopic assessment was performed for fractured specimens for ageing. Data was analyzed using ANOVA and Tukey post hoc test. Results: The mean flexural strength at baseline for Group-1: LAVA™ Zirconia, group (632.7 ± 136.5 MPa) 2: Vita In-Ceram YZ (1036.3 ± 229.6 MPa), and Group-3: Aadva™ Zirconia (1171.3 ± 266.3 MPa) were significantly different. Group-2 and Group-3 specimens showed higher strength compared to Group-1 specimens, irrespective of the ageing duration (p<0.05). Analysis of pooled data for flexural strength for materials by aging period (baseline, after 48 hours and after 2 and ½ years) showed that there was significant reduction of strength with increasing duration (p<0.05). Conclusions: Y-TZP showed variations in flexural strength depending on the material type. Ageing duration exhibited significant influence on the flexural strength of Y-TZP when comparing no ageing to two and half years. Vita In-Ceram YZ and Aadva Zirconia (Zr) showed higher and clinically acceptable flexural strength outcomes. doi: https://doi.org/10.12669/pjms.37.3.3996 How to cite this:Al-Aali KA, Alresayes S, Alhenaki AM, Vohra F, Abduljabbar T. Influence of time and hydration (ageing) on flexural strength of Yttrium stabilized Zirconia polycrystals (Y-TZP) fabricated with different CAD-CAM Systems. Pak J Med Sci. 2021;37(3):---------. doi: https://doi.org/10.12669/pjms.37.3.3996 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Effects of Veneering Ceramic and Methods on Failure Load of Veneered Zirconia

Applied Sciences ◽

10.3390/app11052129 ◽

2021 ◽

Vol 11 (5) ◽

pp. 2129

Author(s):

Hattanas Kumchai ◽

Patrapan Juntavee ◽

Arthur F. Sun ◽

Dan Nathanson

Keyword(s):

Glass Ceramic ◽

Failure Load ◽

Testing Machine ◽

Bending Test ◽

Three Point Bending ◽

Significant Difference ◽

Load To Failure ◽

Cad Cam ◽

Feldspathic Porcelain ◽

Post Hoc

Background: A variety of veneering options to zirconia frameworks are now available. The purpose of this study is to evaluate the effect of veneer materials, veneering methods, cement materials, and aging on the failure load of bilayered veneer zirconia. Material and methods: Zirconia bars (20 × 4 × 1 mm) were veneered to 2 mm total thickness (n = 10/group). Veneering method groups included: 1. Hand-layered feldsparthic porcelain (VM = Vita VM9, Vident) and fluorapatite glass–ceramic (CR = IPS e.max Ceram, IvoclarVivadent); 2. Pressed feldspathic porcelain (PM = Vita PM9, Vident) and fluorapatite glass–ceramic (ZP = IPS e.max ZirPress, IvoclarVivadent); 3. CAD-/CAM-milled feldspathic ceramic (TF = Vitablocs Triluxe Forte, Vident) and lithium-disilicate glass–ceramic (CAD = IPS e.max CAD, IvoclarVivadent). CAD/CAM veneers were either cemented with resin cements (P = Panavia21, KurarayDental), (R = RelyX Ultimate, 3M ESPE), (M = Multilink Automix, Ivoclar Vivadent) or fused with fusion glass–ceramic (C = CrystalConnect, IvoclarVivadent). A three-point bending test (15 mm span, zirconia on tension side) was performed on Instron universal testing machine (ISO 6872) recording load-to-failure (LTF) of first veneer cracks or catastrophic failure. For group VM, PM, TF-M, TF-C, CAD-M, CAD-C, ten more bars were prepared and aged with cyclic loading (100,000 cycles, 50% LTF) and thermocycling (2000 cycles) before testing. Data were analyzed by ANOVA, Tukey HSD post hoc tests, and t-test (α = 0.05). Zirconia veneered with IPS e.max CAD by fusing had significantly higher failure load compared with zirconia veneered with other veneering materials. (p ≤ 0.05). For cemented veneers, the cement type had a significant effect on the failure load of the veneer zirconia specimens. Specimens cemented with Panavia 21 had a lower resistance to loading than other cements. The aging experiment revealed a significant difference in failure load between non-aged and aged bars in groups VM and PM, but not in the groups with CAD-/CAM-milled veneers. In conclusion, veneer materials, veneering methods, and cement materials have a significant effect on the failure load of bilayered veneer zirconia. CAD-/CAM-milled veneer zirconia is not susceptible to aging performed in this study.

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Effect of Glazing on Flexural Strength of Full-Contour Zirconia

International Journal of Dentistry ◽

10.1155/2018/8793481 ◽

2018 ◽

Vol 2018 ◽

pp. 1-5 ◽

Cited By ~ 5

Author(s):

Hattanas Kumchai ◽

Patrapan Juntavee ◽

Arthur F. Sun ◽

Dan Nathanson

Keyword(s):

Flexural Strength ◽

Significant Influence ◽

Testing Machine ◽

Surface Treatments ◽

Bending Test ◽

Three Point Bending ◽

Universal Testing ◽

Heat Treated ◽

Significant Difference ◽

Post Hoc

Objective. The purpose of this study was to evaluate the effect of glazing on flexural strength of highly translucent zirconia materials. Materials and Methods. Specimens of three brands of zirconia bars (Prettau Zirconia, Zirkonzahn; inCoris TZI, Sirona; and Zirlux FC, Pentron Ceramics) were prepared and polished according to manufacturers’ instructions. Final specimen dimensions were 20 × 4 × 2 mm. The specimens from each brand were divided into 3 groups (N = 10): control, heat-treated, and glazed. Heat-treated specimens were fired without the application of the glaze material. The glaze material was applied to the glazed specimens before being fired. A three-point bending test (15 mm span) was performed in an Instron universal testing machine (ISO 6872). Data were analyzed by ANOVA and Tukey’s HSD post hoc test (α = 0.05). Results. Two-way ANOVA showed a significant influence of surface treatments on flexural strength of zirconia materials (P≤0.05). There was no significant difference in flexural strength among the different brands of highly translucent zirconia (P≥0.05). Tukey’s HSD post hoc test showed that specimens in the “glazed” group had significantly lower flexural strength than the control and heat-treated groups (P≤0.05). Conclusion. Within the limitations of the study, external glazing decreased the flexural strength of highly translucent zirconia.

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Influence of the Sintering Type in Ceramics Blocks for Cad-Cam

Odovtos - International Journal of Dental Sciences ◽

10.15517/ijds.v0i0.24434 ◽

2016 ◽

Vol 18 (2) ◽

pp. 91

Author(s):

Martín Kreisler DDS, MSc, PhD ◽

Osmir Oliveira DDS, MSc, PhD

Keyword(s):

Solid State ◽

Flexural Strength ◽

Liquid State ◽

Hardness Test ◽

Test Method ◽

Bending Test ◽

Three Point Bending ◽

Cad Cam ◽

Ceramic Blocks ◽

State Group

The aim of this study was to characterize the influence of the sintering type in the flexural strength and hardness of ceramic blocks for CAD-CAM. Four type of ceramic blocks were selected and distributed according to the type of sintering to be performed: Group G1 - In-Ceram® Alumina / liquid state; Group G2 - In-Ceram® AL / solid state; Group G3 - In-Ceram® Zircon / liquid state; Group G4 - In-Ceram® YZ / solid state. All blocks were cut in bar shape with dimensions of 25 x 5 x 2 mm. and submitted to the three-point bending test and to the Vickers hardness test method. The results, after statistical analysis, showed that the average flexural strength of group G1 (351.7 MPa) and group G3 (356.3 MPa) were significantly lower than those of group G2 (421.9 MPa) and group G4 (758.4 MPa); as well as all hardness averages were significantly different, being higher for group G2 (1.936,6 HV) and group G4 (1.321,4 HV), when compared to group G1 (1.173,3 HV) and group G3 (1.094,6 HV). It was concluded that the solid state sintering proved to be more efficient to obtain maximum densification of the ceramics blocks, resulting in high values of flexural strength and hardness.

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Surface Properties of Polymer Resins Fabricated with Subtractive and Additive Manufacturing Techniques

Polymers ◽

10.3390/polym13234077 ◽

2021 ◽

Vol 13 (23) ◽

pp. 4077

Author(s):

Amal S. Al-Qahtani ◽

Huda I. Tulbah ◽

Mashael Binhasan ◽

Maria S. Abbasi ◽

Naseer Ahmed ◽

...

Keyword(s):

Surface Roughness ◽

Flexural Strength ◽

Testing Machine ◽

Study Groups ◽

Bending Test ◽

P Value ◽

Micro Hardness ◽

Significant Difference ◽

Cad Cam ◽

Manufacturing Techniques

This study aimed to compare the surface roughness, hardness, and flexure strength of interim indirect resin restorations fabricated with CAD-CAM (CC), 3D printing (3D), and conventional techniques (CV). Twenty disk (3 mm × Ø10 mm) and ten bar specimens (25 × 2 × 2 mm) were fabricated for the CC, 3D, and CV groups, to be used for surface roughness, micro-hardness, and flexural strength testing using standardized protocol. Three indentations for Vickers micro-hardness (VHN) were performed on each disk and an average was identified for each specimen. Surface micro-roughness (Ra) was calculated in micrometers (μm) using a 3D optical non-contact surface microscope. A three-point bending test with a universal testing machine was utilized for assessing flexural strength. The load was applied at a crosshead speed of 3 mm/min over a distance of 25 mm until fracture. Means and standard deviations were compared using ANOVA and post hoc Tukey–Kramer tests, and a p-value of ≤0.05 was considered statistically significant. Ra was significantly different among the study groups (p < 0.05). Surface roughness among the CC and CV groups was statistically comparable (p > 0.05). However, 3D showed significantly higher Ra compared to CC and CV samples (p < 0.05). Micro-hardness was significantly higher in 3D samples (p < 0.05) compared to CC and CV specimens. In addition, CC and CV showed comparable micro-hardness (p > 0.05). A significant difference in flexural strength was observed among the study groups (p < 0.05). CC and 3D showed comparable strength outcomes (p > 0.05), although CV specimens showed significantly lower (p < 0.05) strength compared to CC and 3D samples. The 3D-printed provisional restorative resins showed flexural strength and micro-hardness comparable to CAD-CAM fabricated specimens, and surface micro-roughness for printed specimens was considerably higher compared to CAD-CAM and conventional fabrication techniques.

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Effect of Repeated Preheating Cycles on Flexural Strength of Resin Composites

Operative Dentistry ◽

10.2341/11-476-l ◽

2013 ◽

Vol 38 (1) ◽

pp. 33-38 ◽

Cited By ~ 4

Author(s):

M D'Amario ◽

S Pacioni ◽

M Capogreco ◽

R Gatto ◽

M Baldi

Keyword(s):

Flexural Strength ◽

Room Temperature ◽

Testing Machine ◽

Bending Test ◽

Resin Composites ◽

Control Groups ◽

Three Point Bending ◽

Universal Testing ◽

Group A ◽

Significant Factors

SUMMARY The aim of this study was to assess the flexural strengths of three resin composites prepared at room temperature or cured after 20 or 40 cycles of preheating to a temperature of 45°C. Three resin composites were evaluated: Enamel Plus HFO (Micerium) (HFO), Enamel Plus HRi (Micerium) (HRi), Opallis + (FGM) (OPA). One group of specimens for each composite was fabricated under ambient laboratory conditions, whereas in the other groups, the composites were cured after 20 or 40 preheating cycles to a temperature of 45°C in a preheating device. Ten specimens were prepared for each group. A three-point bending test was performed using a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed with a two-way analysis of variance (ANOVA) test and a Games-Howell test (α = 0.05). The two-way ANOVA showed that both the material and the number of heating cycles were significant factors, able to influence the flexural strength values (p<0.05). However, there was not a statistically significant interaction (p>0.05). For all three composites flexural strengths were not affected after 20 preheating cycles in comparison with the control groups (0 preheating cycles) but were, however, significantly decreased when 40 prewarming cycles were conducted. The HRi and OPA groups had the highest flexural strengths, with no statistically significant differences among them. HFO presented significantly lower flexural strengths in comparison with HRi.

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Flexural Strength of Different Monolithic Computer-Assisted Design and Computer-Assisted Manufacturing Ceramic Materials upon Different Thermal Tempering Processes

European Journal of Dentistry ◽

10.1055/s-0040-1713957 ◽

2020 ◽

Vol 14 (04) ◽

pp. 566-574

Author(s):

Niwut Juntavee ◽

Pithiwat Uasuwan

Keyword(s):

Flexural Strength ◽

Tetragonal Zirconia ◽

Ceramic Materials ◽

Bending Test ◽

Lithium Silicate ◽

Computer Assisted ◽

Three Point Bending ◽

Significant Difference ◽

Monolithic Zirconia ◽

Thermal Tempering

Abstract Objective Strength of ceramics related with sintering procedure. This study investigated the influence of different tempering processes on flexural strength of three monolithic ceramic materials. Materials and Methods Specimens were prepared in bar-shape (width × length × thickness = 4 × 14 × 1.2 mm) from yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP, inCoris TZI [I]), zirconia-reinforced lithium silicate (ZLS, Vita Suprinity [V]), and lithium disilicate (LS2, IPS e.max CAD [E]), and sintered with different tempering processes: slow (S), normal (N), and fast (F) cooling procedure (n = 15/group). Flexural strength (σ) was determined using three-point bending test apparatus at 1 mm/min crosshead speed. Statistical Analysis The analysis of variance and Bonferroni’s multiple comparisons were determined for significant difference (α = 0.05). Weibull analysis was applied for survival probability, Weibull modulus (m), and characteristics strength (σo). Microstructures were evaluated with scanning electron microscope and X-ray diffraction. Results The mean ± standard deviation (MPa) of σ, m, and σo were: 1,183.98 ± 204.26, 6.23, 1,271.80 for IS; 1,084.43 ± 204.79, 5.76, 1,170.08 for IN; 777.19 ± 99.77, 8.78, 819.96 for IF; 267.15 ± 32.71, 9.11, 281.48 for VS; 218.43 ± 38.46, 6.40, 234.23 for VN; 252.67 ± 37.58, 7.20, 269.23 for VF; 392.09 ± 37.91, 11.37, 409.23 for ES; 378.88 ± 55.38, 7.45, 403.11 for EN, and 390.94 ± 25.34, 16.00, 403.51 for EF. Thermal tempering significantly affected flexural strength of Y-TZP (p < 0.05), but not either ZLS or LS2 (p > 0.05). Y-TZP indicated significantly higher flexural strength upon slow tempering than others. Conclusion Enhancing flexural strength of Y-TZP can be achieved through slow tempering process and was suggested as a process for monolithic zirconia. Strengthening of ZLS and LS2 cannot be accomplished through tempering; thus, either S-, N-, or F- tempering procedure can be performed. Nevertheless, to minimize sintering time, rapid thermal tempering is more preferable for both ZLS and LS2.

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