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

Polymers ◽  
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.

scholarly journals Effects of Denture Cleansers on Heat-Polymerized Acrylic Resin: A Five-Year-Simulated Period of Use

2015 ◽  
Vol 26 (4) ◽  
pp. 404-408 ◽  
Author(s):  
Carolina Noronha Ferraz Arruda ◽  
Danilo Balero Sorgini ◽  
Viviane de Cássia Oliveira ◽  
Ana Paula Macedo ◽  
Cláudia Helena Silva Lovato ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Flexural Strength ◽  
Testing Machine ◽  
Color Stability ◽  
Acrylic Resin ◽  
National Bureau ◽  
Alkaline Peroxide ◽  
Significant Difference ◽  
Bonferroni Test ◽  
Clinically Significant

<p>This study evaluated color stability, surface roughness and flexural strength of acrylic resin after immersion in alkaline peroxide and alkaline hypochlorite solutions, simulating a five-year-period of use. Sixty disc-shaped (16x4 mm) and 60 rectangular specimens (65x10x3.3 mm) were prepared from heat-polymerized acrylic resin (Lucitone 550) and assigned to 3 groups (n=20) of immersion (20 min): C1: distilled water; AP: warm water and one alkaline peroxide tablet; SH: 0.5% NaOCl solution. Color data (∆E) were determined by a colorimeter and also quantified according to the National Bureau of Standards units. A rugosimeter was used to measure roughness (μm) and the flexural strength (MPa) was measured using a universal testing machine. Data were evaluated by Kruskal-Wallis followed by Dunn tests (color stability and surface roughness) and by one-way ANOVA and Bonferroni test (flexural strength). For all tests was considered α=0.05. AP {0.79 (0.66;1.42)} caused color alteration significantly higher than C1 {0.45 (0.37;0.57)} and SH {0.34 (0.25;0.42)}. The mean ∆Ε values quantified by NBS were classified as "trace" for C1 (0.43) and SH (0.31) and "slight" for AP (0.96). SH {-0.015 (-0.023;0.003)} caused significantly higher ΔRa than the C1 {0.000 (-0.004;0.010)} and AP {0.000 (-0.009;0.008)} groups. There was no statistically significant difference among the solutions for flexural strength (C1: 84.62±16.00, AP: 85.63±12.99, SH: 84.22±14.72). It was concluded that immersion in alkaline peroxide and NaOCl solutions simulating a five-year of 20 min daily soaking did not cause clinically significant adverse effects on the heat-polymerized acrylic resin.</p>

scholarly journals Evaluation of the flexural strength and surface roughness of dental material after immersion in coffee

2021 ◽  
Vol 10 (3) ◽  
pp. e30510312486
Author(s):  
Patrícia Capellato ◽  
Ana Paula Rosifini Alves Claro
Keyword(s):  
Surface Roughness ◽  
Flexural Strength ◽  
Testing Machine ◽  
Dental Material ◽  
Bending Test ◽  
Control Group ◽  
Test Surface ◽  
Physiological Serum ◽  
Group A ◽  
Group B

This study was done in order to evaluate the changes in flexural strength and surface roughness in dental material restorations after immersion in coffee. Bars specimens (2mm x 2mm x 25 mm) of Z100 3M/ESPE were made according to ISO 4049 using aluminum molds. After curing, the specimens were then randomly divided into five groups and conditioned at 37°C in physiological serum. In all groups, except control, samples were immersed in coffee for ten minutes daily. In group A, the samples were immersed in coffee. For group B, after to be immersed in coffee, samples were immersed in distilled water for one minute. For group C, samples were immersed in mouthwash for one minute. For group D, samples were brushing for ten minutes, with load of 250g and 4250 cycles after all treatments the samples were stored in physiological serum again. In control group, samples were only stored in physiological serum. The five groups were then divided into 2 subgroups according storage time, six and nine weeks, respectively. Flexural strength was determined using three point bending test in a universal testing machine. All the tests were carried out at a room temperature and samples were maintained in physiological serum during the test. Surface roughness measurements were made using a surface roughness tester. All data were analyzed using one-way analysis of variance (ANOVA) followed by Dunnet tests. The ANOVA indicated no difference in the means of surface roughness and significant was observed for flexural strength between control group and one group (coffee).

scholarly journals Influence of surface treatments in flexural strength and superficial topography of a lithium disilicate ceramic

2019 ◽  
Vol 22 (3) ◽  
pp. 305-312
Author(s):  
Natalia Rivoli Rossi ◽  
Tabata Do Prado Sato ◽  
Caroline Cotes Marinho ◽  
Vanessa Cruz Macedo ◽  
Tarcisio José de Arruda Paes Junior ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Flexural Strength ◽  
Lithium Disilicate ◽  
Surface Treatments ◽  
P Value ◽  
Sem Images ◽  
Ultrasonic Bath ◽  
Significant Difference ◽  
Ceramic Blocks

The aim of the study was to evaluate the influence of different surface post-etching treatments in flexural strength, contact angle and surface roughness of a lithium disilicate ceramic. 60 bars (16x2x4mm) were divided in six groups (n=10): C, no treatment; HF, hydrofluoric acid for 20s (HF) + washing (60s), drying (30s); HFL, HF + washing (60s), drying (30s) and luting; HFNL, HF + washing (60s) + neutralization with sodium bicarbonate (SB) for 40s + washing (5s), drying (30s) and luting; HFUL, HF + washing (60s) + ultrasonic bath (UB) for 4 min, drying (30s) and luting; HFNUL, HF + washing (60s) + SB (40s) + UB (4 min) and luting. The bars were submitted to three-points flexural strength test. To analyze roughness and contact angle 25 ceramic blocks (12x7x7 mm) were divided into five groups (n=5): C - no treatment; HF - HF ; HFU - HF and UB for 5 min ; HFN - HF and SB; HFNU - HF, UB and SB. A scanning electron microscope (SEM) analysed the surface of the samples. ANOVA one-way statistical analysis was done for comparison of results. There was no statistical difference for flexural strength (p-value=0.15) and for surface roughness (p-valor=0.15). However, it was obtained statistically significant difference for contact angle (p-valor=0.00). SEM images showed precipitates after the acid etching, which were removed by post-etching treatments. It can be concluded that the different post-etching surface treatments did not increase the flexural strength, surface roughness and ceramic wetting, but it influenced the SEM images.

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

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.

scholarly journals Effect of Glazing on Flexural Strength of Full-Contour Zirconia

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
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.

scholarly journals Comparative analysis of flexural strength of abraded and polished porcelain surfaces – an in vitro study

2021 ◽  
Vol 14 (1) ◽  
pp. 61-67
Author(s):  
Prathibha Nandagiri ◽  
◽  
Mamidi Praveen ◽  
Shikha Singh ◽  
Monika Singh ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Testing Machine ◽  
The Other ◽  
Control Group ◽  
P Value ◽  
Diamond Bur ◽  
Significant Difference ◽  
Fine Diamond ◽  
Ceramic Restorations

Typically, prosthodontists adjust ceramic restorations glazed surface by grinding prior to insertion. Such alterations of surfaces are necessary for the correction of occlusal interferences. We aimed to evaluate and compare the change in flexural strength of ceramic surfaces after re-glazing and polishing. This study included 40 samples of ceramic blocks that were fabricated and glazed, and then fired in accordance with the manufacturer’s recommendations. The sample was randomly divided into four groups of 10 samples each. The first group was the control group with unaltered glazed samples. The second group was abraded with an extra-fine diamond bur followed by re-glazing, and the other two groups were polished with two commercially available polishing kits after abrading them with an extra-fine diamond bur. The samples were tested for their flexural strength using a universal testing machine. On the application of the F test on the means of all the groups, a value greater than 0.05 was found, which meant that there is no statistically significant difference in flexural strength values between the groups (P-value>0.05). Since the flexural strength values of the polished group were comparable to the other groups, polishing can be used instead of re-glazing for ceramic restorations. This reduces an additional clinical appointment for the patient and saves working time.

scholarly journals Effect of Hydrofluoric Acid Surface Treatments on Surface Roughness and Three-Point Flexural Strength of Suprinity Ceramic

2020 ◽  
Author(s):  
Nazanin Keshmiri ◽  
Homayoon Alaghehmand ◽  
Faraneh Mokhtarpour
Keyword(s):  
Surface Roughness ◽  
Flexural Strength ◽  
Hydrofluoric Acid ◽  
Testing Machine ◽  
Etching Time ◽  
Control Group ◽  
Force Microscopy ◽  
Atomic Force ◽  
Significant Difference ◽  
Before And After

Objectives: This study aimed to evaluate the effects of hydrofluoric acid (HF) concentration and etching time on the surface roughness (SR) and three-point flexural strength of Suprinity and to analyze the surface elements before and after etching. Materials and Methods: To measure the SR, 70 specimens of Suprinity (2×4×5mm3) were assigned to seven groups (n=10). Six groups were etched for 20, 60, and 120 seconds with 5% and 10% HF and 7th group was the control group. Specimens were evaluated using atomic force microscopy (AFM). One specimen from each group was used to analyze the surface elements using scanning electron microscopy (SEM). For measuring the three-point flexural strength, 60 specimens were divided into six groups (n=10) and etched as previously described. The flexural strength was measured using a universal testing machine. T-test, one-way analysis of variance (ANOVA), and two-way ANOVA were used for statistical analyses (P<0.05). Results: The 10% concentration of HF caused higher SR compared to the 5% HF. The effect of HF concentration on the flexural strength was significantly different in the 20- and 60-second etching groups. Different etching times had no significantly different effect on the SR. With 5% HF, the flexural strength was significantly higher for 20-second etching time than for the etching times of 60 and 120 seconds. With 10% HF, there was a significant difference in flexural strength between etching times of 20 and 120 seconds. The atomic percentage (at%) of silica was enhanced by increasing the etching time. Conclusions: The best surface etching protocol comprises 10% HF used for 20 seconds.

scholarly journals Comparison of physical and mechanical properties of microwave-polymerized acrylic resin after disinfection in sodium hypochlorite solutions

2009 ◽  
Vol 20 (4) ◽  
pp. 331-335 ◽  
Author(s):  
Helena de Freitas Oliveira Paranhos ◽  
Letícia Resende Davi ◽  
Amanda Peracini ◽  
Rafael Bellini Soares ◽  
Cláudia Helena da Silva Lovato ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Flexural Strength ◽  
Sodium Hypochlorite ◽  
Testing Machine ◽  
Physical And Mechanical Properties ◽  
Color Stability ◽  
Acrylic Resin ◽  
Bending Test ◽  
Water Control ◽  
Before And After

This study evaluated the color stability, surface roughness and flexural strength of a microwave-polymerized acrylic resin after immersion in sodium hypochlorite (NaOCl), simulating 20 min of disinfection daily during 180 days. Forty disk-shaped (15 x 4 mm) and 40 rectangular (65 x 10 x 3 mm) specimens were prepared with a microwave-polymerized acrylic resin (Onda-Cryl). Specimens were immersed in either 0.5% NaOCl, 1% NaOCl, Clorox/Calgon and distilled water (control). Color measurements were determined by a portable colorimeter. Three parallel lines, separated by 1.0 mm, were registered on each specimen before and after immersion procedures to analyze the surface roughness. The flexural strength was measured using a 3-point bending test in a universal testing machine with a 50 kgf load cell and a crosshead speed of 1 mm/min. Data were analyzed statistically by ANOVA and Tukey's test (?=0.05). There was no statistically significant differences (p>0.05) among the solutions for color, surface roughness and flexural strength. It may be concluded that immersion in NaOCl solutions simulating short-term daily use during 180 days did not influence the color stability, surface roughness and flexural strength of a microwave-polymerized acrylic resin.

scholarly journals Effect of Sandblasting Angle and Distance on Biaxial Flexural Strength of Zirconia-based Ceramics

2017 ◽  
Vol 18 (6) ◽  
pp. 443-447 ◽  
Author(s):  
Safoura Ghodsi ◽  
Somayeh Zeighami ◽  
Ali Gheidari ◽  
Hoseinali Mahgoli ◽  
Ahmad Rohanian
Keyword(s):  
Surface Roughness ◽  
Flexural Strength ◽  
Surface Treatment ◽  
Study Groups ◽  
Treatment Method ◽  
Luting Cements ◽  
Significant Difference ◽  
Biaxial Flexural Strength ◽  
Nozzle Head

ABSTRACT Aim Surface treatment is necessarily required for bonding of zirconia to the veneering porcelain and luting cements. Sandblasting is the most common and probably the most efficient surface treatment method. Sandblasting roughens the surface and may affect the flexural strength of zirconia. Different sandblasting protocols may yield variable results. This study sought to assess the effect of sandblasting angle and distance on the biaxial flexural strength of zirconia-based ceramics. Materials and methods This in vitro experimental study was conducted on 50 zirconia discs measuring 1.2 ± 0.2 mm in thickness and 15 ± 0.2 mm in diameter, which were randomly divided into five groups (n = 10) of one control and four experimental groups subjected to sandblasting with 110 µm aluminum oxide particles under 2 bar pressure for 10 seconds at 15 and 25 mm distances and 45 and 90° angles (between the nozzle head and zirconia surface). Surface roughness was measured by a roughness tester and samples were subjected to thermocycling followed by biaxial flexural strength testing according to ISO6872. The data were analyzed using one-way analysis of variance (p < 0.05). Results No statistically significant difference was noted in the mean biaxial flexural strength of the five groups (p = 0.40). Different sandblasting protocols yielded significantly different surface roughness values (p < 0.001). The highest and the lowest mean surface roughness belonged to 15 mm/90° (0.51 µm) and control (0.001 µm) groups respectively. Conclusion Change in sandblasting angle and distance had no significant effect on the biaxial flexural strength of zirconiabased ceramic, but surface roughness was significantly different in the study groups. Clinical significances Regardless of sandblasting angle, increasing distance to 25 mm significantly decreases surface roughness that may negatively affect zirconia bond strength. How to cite this article Zeighami S, Gheidari A, Mahgoli H, Rohanian A, Ghodsi S. Effect of Sandblasting Angle and Distance on Biaxial Flexural Strength of Zirconia-based Ceramics. J Contemp Dent Pract 2017;18(6):443-447.

scholarly journals Comparative Evaluation of Flexural Strength of Glass Ionomer Cement and Cention N in Artificial Medium Over Time Intervals - An In-Vitro Study

2021 ◽  
Vol 10 (32) ◽  
pp. 2609-2614
Author(s):  
Risana K. ◽  
Prathyusha P ◽  
Amith Adyanthaya ◽  
Aparna Sivaraman ◽  
Nazreen Ayub K ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Artificial Saliva ◽  
Testing Machine ◽  
Glass Ionomer Cement ◽  
Bending Test ◽  
Glass Ionomer ◽  
Time Intervals ◽  
Significant Difference ◽  
Duration Of Storage ◽  
Ionomer Cement

BACKGROUND Glass ionomer cement (GIC) is a versatile restorative cement in paediatric dentistry. Due to its less flexural strength, alternative materials have been developed. Cention N is one such material, but since it’s a new material evidence is lacking regarding its physical properties, especially flexural strength for evaluating its clinical outcome. We wanted to compare the flexural strength of glass ionomer cement and Cention N stored in artificial saliva and its variation over different time intervals, i.e., after 24 hours, 1 week and 4 weeks. METHODS A total of 30 specimens were prepared for GIC (Fuji IX) and Cention N and were further categorized according to the duration of storage time of 24 hours, 1 week and 4 weeks (N = 10). A 3 - point bending test using a universal testing machine was used to evaluate the flexural strength. RESULTS GIC Fuji IX showed a mean flexural strength of 35.296 ± 1.61 Mpa at the end of 24 hours, 47.234 ± 4.12 after 1 week and 66.039 ± 11.05 Mpa at the end of 4 weeks. GIC showed a statistically significant increase of flexural strength from 24 hours to one week and a further increase after 4 weeks of storage. The flexural strength of Cention N at 24 hours was 175.985 ± 22.11 Mpa, at the end of one week was 163.486 ± 17.55 MPa, and after 4 weeks was 175.437 ± 27.22 Mpa. Cention N did not show any statistically significant change in flexural strength value from 24 hours to 4 weeks. Cention N showed highly significant difference between flexural strength compared to GIC at all - time intervals. CONCLUSIONS Cention N has a superior flexural strength compared to GIC at all - time intervals. KEY WORDS Cention N, Flexural Strength, Glass Ionomer Cement

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