Influence of the Printing Angle and Load Direction on Flexure Strength in 3D Printed Materials for Provisional Dental Restorations

The CAD/CAM techniques, especially additive manufacturing such as 3D printing, constitute an ever-growing part of obtaining different dental appliances and restorations. Of these, provisional restorations are of frequent use in daily dental practice and are the object of this study. Masticatory and parafunctional forces determine flexure on these prostheses. This study investigates the influence of the printing angle and loading direction of the applied force on the flexure strength of two commercially available printable resins—Detax Freeprint Temp and Nextdent MFH Vertex dental. Ten rectangular beam specimens printed at the angle of 0, 45 and 90 degrees were fabricated of each of these materials, with an addition of 10 at 0 degrees for the investigation of the load direction. Three-point bending tests were performed in a universal testing machine. Flexure strength, strain at break and Young’s modulus were determined and a statistical analysis was performed on the obtained data. According to the statistical analysis, the flexural strength has a significance dependence with respect to degrees of orientation, for both investigated materials.

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Three-Point Bending Tests of Zirconia Core/Veneer Ceramics for Dental Restorations

International Journal of Dentistry ◽

10.1155/2013/831976 ◽

2013 ◽

Vol 2013 ◽

pp. 1-5 ◽

Cited By ~ 31

Author(s):

Massimo Marrelli ◽

Carmine Maletta ◽

Francesco Inchingolo ◽

Marco Alfano ◽

Marco Tatullo

Keyword(s):

Surface Roughness ◽

Comparative Study ◽

Mechanical Strength ◽

Surface Hardness ◽

Mechanical Tests ◽

Bending Tests ◽

Three Point Bending ◽

Dental Restorations ◽

Modes Of Failure ◽

Cad Cam

Introduction. The mechanical strength and the surface hardness of commercially available yttrium-doped zirconia were investigated. Furthermore, a comparative study of eight different ceramic veneers, to be used for the production of two-layered all-ceramic restorative systems, was carried out.Materials and Methods. Four types of zirconia specimens were analyzed, according to a standard ISO procedure (ISO 6872). Besides, two-layered zirconia-veneer specimens were prepared for three-point bending tests.Results. A strong effect of the surface roughness on the mechanical strength of zirconia specimens was observed. Finally, a comparative study of eight commercially available veneering ceramics shows different modes of failure between the selected veneers.Conclusion. The results indicate that close attention should be paid to the preparation of zirconia-based crowns and bridges by CAD/CAM process, because surface roughness has an important effect on the mechanical strength of the material. Finally, the results of the mechanical tests on two-layered specimens represent an important support to the choice of the veneering ceramic.

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Direct Inkjet Printing of Dental Prostheses Made of Zirconia

Journal of Dental Research ◽

10.1177/0022034509339988 ◽

2009 ◽

Vol 88 (7) ◽

pp. 673-676 ◽

Cited By ~ 141

Author(s):

J. Ebert ◽

E. Özkol ◽

A. Zeichner ◽

K. Uibel ◽

Ö. Weiss ◽

...

Keyword(s):

Inkjet Printing ◽

Solid Content ◽

The Novel ◽

Dental Restorations ◽

Drop On Demand ◽

Dental Prostheses ◽

All Ceramic ◽

Cad Cam ◽

3D Printed ◽

Limited Accuracy

CAD/CAM milling systems provide a rapid and individual method for the manufacturing of zirconia dental restorations. However, the disadvantages of these systems include limited accuracy, possible introduction of microscopic cracks, and a waste of material due to the principle of the ‘subtractive process’. The hypothesis of this study was that these issues can be overcome by a novel generative manufacturing technique, direct inkjet printing. A tailored zirconia-based ceramic suspension with 27 vol% solid content was synthesized. The suspension was printed on a conventional, but modified, drop-on-demand inkjet printer. A cleaning unit and a drying device allowed for the build-up of dense components of the size of a posterior crown. A characteristic strength of 763 MPa and a mean fracture toughness of 6.7 MPam0.5 were determined on 3D-printed and subsequently sintered specimens. The novel technique has great potential to produce, cost-efficiently, all-ceramic dental restorations at high accuracy and with a minimum of materials consumption.

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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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Torque Mechanical Evaluation for 3D Printed Orthodontic Springs with Different Parameters: Invitro Study

10.21203/rs.3.rs-19614/v1 ◽

2020 ◽

Author(s):

Ahmed Othman ◽

Steven Hartman ◽

Dragan Ströbele ◽

Jassin Arnold ◽

Constantin von See

Keyword(s):

Testing Machine ◽

Control Group ◽

3D Printer ◽

Coil Design ◽

Flexible Material ◽

Universal Testing ◽

Length Group ◽

Cad Cam ◽

3D Printed ◽

Sydney Australia

Abstract Background: The purpose of the presented investigation is to evaluate the resulting torque on loaded 3D printed springs using different coil thickness and length. Methods: Specimens were designed and printed using the 3D printer MAX (Asiga, Sydney, Australia) with 3D printable, experimental, flexible material (Code:BM2008, GC, Tokyo, Japan). The specimens were divided into three groups according to spring coil design. Control group (n=18), length group (n=19) and thickness group (n=22). Groups were tested using a Sauter Machine for torque calculation (DB, Grindelwald, Switzerland) in conjunction with a universal testing machine (Zwick Z010, Ulm, Germany) for clock-wise and anti-clockwise testing. Statistical analysis was performed using the Steel-Dwass test to compare median values of the three groups in both testing directions (p<0.001). Results: The highest torque value was determined in the thickness group for both clockwise and anti-clockwise testing directions, achieving 44.00N/mm and 39.62N/mm respectively. For the thickness group values ranged from 21.28N/mm anti-clockwise to 44.00N/mm clockwise. The length group ranged from 21.65N/mm to 11.04N/mm in clockwise direction and from 18.04N/mm to 11.38N/mm in counter-clockwise testing. The control group ranged from 22.72N/mm to 17.18N/mm in the clock-wise direction while in the anti-clock wise testing it ranged from 21.34N/mm to 16.02N/mm. Conclusions: 3D printed springs are being affected by diameter than length as a design parameter compared to the control group. The thickness group values are statistically significant than the length group (P<0.001). Key words: CAD/CAM, 3D printing, Digital Orthodontics, Torque, Springs.

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Effects of Artificial Tooth Brushing and Hydrothermal Aging on the Mechanical Properties and Color Stability of Dental 3D Printed and CAD/CAM Materials

Materials ◽

10.3390/ma14206207 ◽

2021 ◽

Vol 14 (20) ◽

pp. 6207

Author(s):

Na-Eun Nam ◽

Seung-Ho Shin ◽

Jung-Hwa Lim ◽

June-Sung Shim ◽

Jong-Eun Kim

Keyword(s):

Surface Roughness ◽

Computer Aided Design ◽

Color Stability ◽

Color Difference ◽

Hydrothermal Aging ◽

Denture Teeth ◽

Computer Aided ◽

Cad Cam ◽

3D Printed ◽

Printed Materials

This study analyzed the surface roughness and waviness, Vickers hardness (VHN), and color changes of six types of 3D printed resins and computer-aided design/computer-aided manufacturing (CAD/CAM) materials after artificial toothbrushing. The average surface roughness height (Ra) change of Formlabs denture teeth A2 resin (FMLB) was not significant between after artificial toothbrushing (0.17 ± 0.02 μm and 0.17 ± 0.05 μm, respectively; mean ± standard deviation). However, the Ra value increased significantly in all remaining groups. Regarding waviness, polymethylmethacrylate (PMMA) had the largest increases in average waviness height (Wa) and maximum surface waviness height (Wz) between, before (0.43 ± 0.23 μm and 0.08 ± 0.02 μm), and after (8.67 ± 4.03 μm, 1.30 ± 0.58 μm) toothbrushing. There were no significant changes in Wa for Formlabs denture teeth A2 resin (FMLB) and NextDent C&B (NXT). After artificial toothbrushing, the dispersed-filler composite (DFC) group had the largest color difference (ΔE, of 2.4 ± 0.9), and the remaining materials had smaller changes than the clinical acceptance threshold of ΔE = 2.25. The VHN of FMLB and NXT were 9.1 ± 0.4 and 15.5 ± 0.4, respectively, and were not affected by artificial toothbrushing. The flexural strengths of the 3D printed materials were 139.4 ± 40.5 MPa and 163.9 ± 14.0 MPa for FMLB and NXT, respectively, which were similar to those of the polycarbonate and PMMA groups (155.2 ± 23.6 MPa and 108.0 ± 8.1 MPa, respectively). This study found that the evaluated 3D printed materials had mechanical and optical properties comparable to those of CAD/CAM materials and were stable even after artificial toothbrushing and hydrothermal aging.

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Flexural Strength of Composite Based Provisional Crown Materials

International Journal of Innovative Research in Medical Science ◽

10.23958/ijirms/vol06-i01/1055 ◽

2021 ◽

Vol 6 (01) ◽

pp. 78-81

Author(s):

Osama Qutub ◽

Salman Khalid Bashnani ◽

Faisal Khalid Bashnaini

Keyword(s):

Composite Material ◽

Flexural Strength ◽

Treatment Time ◽

Testing Machine ◽

Bending Test ◽

Computer Assisted ◽

Three Point Bending ◽

Long Span ◽

Cad Cam ◽

Group 2

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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Preliminary feasibility torque mechanical evaluation for 3D printed orthodontic springs with different parameters: invitro study

10.21203/rs.3.rs-19614/v2 ◽

2020 ◽

Author(s):

Ahmed Othman ◽

Steven Hartman ◽

Dragan Ströbele ◽

Jassin Arnold ◽

Constantin von See

Keyword(s):

Testing Machine ◽

Control Group ◽

3D Printer ◽

Coil Design ◽

Flexible Material ◽

Universal Testing ◽

Length Group ◽

Cad Cam ◽

3D Printed ◽

Sydney Australia

Abstract Background: The purpose of the presented investigation is to evaluate the resulting torque on loaded 3D printed springs using different coil thickness and length.Methods: Specimens were designed and printed using the 3D printer MAX (Asiga, Sydney, Australia) with 3D printable, experimental, flexible material (Code:BM2008, GC, Tokyo, Japan). The specimens were divided into three groups according to spring coil design. Control group (n=18), length group (n=19) and thickness group (n=22). Groups were tested using a Sauter Machine for torque calculation (DB, Grindelwald, Switzerland) in conjunction with a universal testing machine (Zwick Z010, Ulm, Germany) for clock-wise and anti-clockwise testing. Statistical analysis was performed using the Steel-Dwass test to compare median values of the three groups in both testing directions (p<0.001). Results: The highest torque value was determined in the thickness group for both clockwise and anti-clockwise testing directions, achieving 44.00N/mm and 39.62N/mm respectively. The length group ranged from 21.65N/mm to 11.04N/mm in clockwise direction and from 18.04N/mm to 11.38N/mm in counter-clockwise testing. The control group ranged from 22.72N/mm to 17.18N/mm in the clock-wise direction while in the anti-clock wise testing it ranged from 21.34N/mm to 16.02N/mm.Conclusions: The amount of torque produced from the CAD/CAM springs is being affected by diameter more than the length design parameter in comparison to the control group. The values of the thickness group are significantly higher than those of the length group (P<0.001).

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Preliminary feasibility torque mechanical evaluation for 3D printed orthodontic springs with different parameters: in vitro study

BMC Oral Health ◽

10.1186/s12903-021-01473-8 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Ahmed Othman ◽

Steven Hartman ◽

Dragan Ströbele ◽

Jassin Arnold ◽

von See

Keyword(s):

Testing Machine ◽

In Vitro Study ◽

Control Group ◽

Flexible Material ◽

Length Group ◽

Computer Aided ◽

Cad Cam ◽

3D Printed ◽

Sydney Australia

Abstract Background The purpose of the presented investigation is to evaluate the resulting torque on loaded 3D printed springs using different coil thickness and length. Methods Specimens were designed and printed using the 3D printer MAX (Asiga, Sydney, Australia) with 3D printable, experimental, flexible material (Code:BM2008, GC, Tokyo, Japan). The specimens were divided into three groups according to spring coil design. Control group (n = 18), length group (n = 19) and thickness group (n = 22). Groups were tested using a Sauter Machine for torque calculation (DB, Grindelwald, Switzerland) in conjunction with a universal testing machine (Zwick Z010, Ulm, Germany) for clock-wise and anti-clockwise testing. Statistical analysis was performed using the Steel–Dwass test to compare median values of the three groups in both testing directions (p < 0.001). Results The highest torque value was determined in the thickness group for both clockwise and anti-clockwise testing directions, achieving 44.00 N/mm and 39.62 N/mm respectively. The length group ranged from 21.65 to 11.04 N/mm in clockwise direction and from 18.04 to 11.38 N/mm in counter-clockwise testing. The control group ranged from 22.72 to 17.18 N/mm in the clock-wise direction while in the anti-clock wise testing it ranged from 21.34 to 16.02 N/mm. Conclusions The amount of torque produced from the computer aided designing/computer aided manufacturing (CAD/CAM) springs is being affected by diameter more than the length design parameter in comparison to the control group. The values of the thickness group are significantly higher than those of the length group (P < 0.001).

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Tensile strength of 3D printed materials: Review and reassessment of test parameters

Materials Testing ◽

10.3139/120.111203 ◽

2018 ◽

Vol 60 (7-8) ◽

pp. 679-686 ◽

Cited By ~ 3

Author(s):

Jim Floor ◽

Bas van Deursen ◽

Erik Tempelman

Keyword(s):

Tensile Strength ◽

Test Parameters ◽

3D Printed ◽

Printed Materials

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Investigation of the Deformation Twins on the Bending Cross Section of TA2 Titanium Sheet

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.837.41 ◽

2020 ◽

Vol 837 ◽

pp. 41-45

Author(s):

Shuai Sun ◽

Kai Hua Liu

Keyword(s):

Electron Backscatter Diffraction ◽

Testing Machine ◽

Pure Titanium ◽

Titanium Sheet ◽

Bending Tests ◽

Three Point Bending ◽

Deformation Twins ◽

Ebsd Technique ◽

Backscatter Diffraction ◽

Deformation Area

In order to determine the evolution features of deformation twins for TA2 commercial pure titanium (cp-TA2), the TA2 samples were bent under different bending angles in three-point bending tests via a universal testing machine. The electron backscatter diffraction (EBSD) technique was applied to identify the grain boundaries (GBs) and twin boundaries (TBs) in the bending areas. The results reveal that the type of deformation area would effect the evolution of different deformation twins. It is inferred that the state of stress would promote the multiplication of the same type of deformation twins.

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