Effect of Repeated Preheating Cycles on Flexural Strength of Resin Composites

2013 ◽  
Vol 38 (1) ◽  
pp. 33-38 ◽  
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.

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 Effect of Preheating on the Mechanical Properties of Resin Composites

2008 ◽  
Vol 02 (04) ◽  
pp. 263-268 ◽  
Author(s):  
Mine Betül Uctasli ◽  
Hacer Deniz Arisu ◽  
Lippo VJ Lasilla ◽  
Pekka K Valittu
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Testing Machine ◽  
Bending Test ◽  
Resin Composites ◽  
Three Point Bending ◽  
Commercial Resin ◽  
Significant Difference ◽  
Light Curing ◽  
Post Hoc

ABSTRACTObjectives: The purpose of this study was to compare the flexural strength and modulus of two commercial resin composites, at room temperature and 40, 45 and 50�C prior to light polymerization with standard and step-cure protocols.Methods: One nanohybrid (Grandio, VOCO, Cuxhaven, Germany), and microhybrid compositeresin (Filtek Z250, 3M ESPE, St. Paul, MN, USA) were used. The materials were inserted into rectangular moulds at room temperature or preheated to a temperature of 40, 45 or 50°C and cured with standard or step-cure protocols with high intensity halogen (Elipar Highlight, 3M-ESPE, St. Paul, MN, USA). Ten specimens were prepared for each preheating and light curing protocol. A three-point bending test was performed using a universal testing machine at a crosshead speed of 1 mm/min. The data were analyzed by one-way analysis of variance and Tukey’s post hoc tests (P<.05) to examine the effect of curing protocol and preheating. Pearson’s correlation test was used to determine the correlation between tested mechanical properties and preheating.Results: There were no statistically significant difference between tested mechanical properties of the materials, curing protocols and temperature of the materials. No significant correlation was found between preheating and tested mechanical properties.Conclusions: The mechanical properties of the tested materials did not changed by preheating so the tested materials could be preheated because of the other potential clinical advantages like more adaptation to the cavity walls. (Eur J Dent 2008;2:263-268)

scholarly journals Effect of thermocycling aging on the flexural strength of feldspathic ceramic

2018 ◽  
Vol 21 (3) ◽  
pp. 315
Author(s):  
Ronaldo Lúís Almeida de Carvalho ◽  
Estevão Tomomitsu Kimpara ◽  
Eduardo Bresciani ◽  
Márcia Carneiro Valera ◽  
Renata Marques Melo
Keyword(s):  
Electron Microscopy ◽  
Flexural Strength ◽  
Testing Machine ◽  
Bending Test ◽  
Catastrophic Failure ◽  
Thermal Cycles ◽  
Mean Values ◽  
Three Point Bending ◽  
Universal Testing ◽  
Scanning Electron

<p><strong>Objective: </strong>The aim of the study was to evaluate the effect of aging through different thermocycling protocols on the flexural strength of a feldspathic ceramic. <strong>Material and Methods:</strong> Fifty ceramic bars, Vitablock Mark II (VITA), with dimensions of 18X4X2mm were prepared. The bars were randomly distributed to the groups (n = 10), which were defined according to the number of thermal cycles (TCy): G0 - no TCy; G500 - 500 cycles of TCy; G6000 - 6000 TCy; G10000 - 10000 TCy; G15000 - 15000 TCy. After aging, the specimens were subjected to the three point bending test in a universal testing machine (EMIC DL 1000), under 0.5mm/min speed and loading of 50kgf, until catastrophic failure. A sample of each group was evaluated for topographic morphology under Scanning Electron Microscopy. <strong>Results:</strong> For mechanical testing, the following mean values and standard deviation (MPa) were obtained: G0 (99.78 ± 5.07); G500 (101.64 ± 5.59); G6000 (98.13 ± 4.95); G10000 (91.77 ± 9.68); G15000 (101.51 ± 4.22). An analysis of variance by regression equation (p = 0.387) was performed, demonstrating a weak and non-significant correlation between flexural strength and number of thermal cycles. <strong>Conclusion: </strong>It can be concluded that aging in water solely by different numbers of temperature cycles did not influence on the flexural strength of a feldspathic ceramic.</p><p> </p><p><strong>Keywords</strong></p><p> Material resistance; Aging; Ceramics.</p>

scholarly journals Flexural Properties and Elastic Modulus of Different Esthetic Restorative Materials: Evaluation after Exposure to Acidic Drink

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Andrea Scribante ◽  
Marco Bollardi ◽  
Marco Chiesa ◽  
Claudio Poggio ◽  
Marco Colombo
Keyword(s):  
Elastic Modulus ◽  
Flexural Strength ◽  
Water Immersion ◽  
Testing Machine ◽  
Distilled Water ◽  
Resin Composites ◽  
Restorative Material ◽  
Universal Testing ◽  
Restorative Materials ◽  
Acidic Beverages

Background. Acidic beverages, such as soft drinks, can produce erosion of resin composites. The purpose of the present study was to investigate mechanical properties of different esthetic restorative materials after exposure to acidic drink. Methods. Nine different composites were tested: nanofilled (Filtek Supreme XTE, 3M ESPE), microfilled hybrid (G-ænial, GC Corporation), nanohybrid Ormocer (Admira Fusion, Voco), microfilled (Gradia Direct, GC Corporation), microfilled hybrid (Essentia, GC Corporation), nanoceramic (Ceram.X Universal, Dentsply De Trey), supranano spherical hybrid (Estelite Asteria, Tokuyama Dental Corporation), flowable microfilled hybrid (Gradia Direct Flo, GC Corporation), and bulk fill flowable (SureFil SDR flow, Dentsply De Trey). Thirty specimens of each esthetic restorative material were divided into 3 subgroups (n=10): specimens of subgroup 1 were used as control, specimens of subgroup 2 were immersed in 50 ml of Coca Cola for 1 week, and specimens of subgroup 3 were immersed in 50 ml of Coca Cola for 1 month. Flexural strength and elastic modulus were measured for each material with an Instron Universal Testing Machine. Data were submitted to statistical analysis. Results. After distilled water immersion, nanofilled composite showed the highest value of both flexural strength and elastic modulus, but its flexural values decreased after acidic drink immersion. No significant differences were reported between distilled water and acidic drink immersion for all other materials tested both for flexural and for elastic modulus values. Conclusions. Even if nanofilled composite showed highest results, acidic drink immersion significantly reduced flexural values.

scholarly journals Influence of a Repeated Preheating Procedure on Mechanical Properties of Three Resin Composites

2015 ◽  
Vol 40 (2) ◽  
pp. 181-189 ◽  
Author(s):  
M D'Amario ◽  
F De Angelis ◽  
M Vadini ◽  
N Marchili ◽  
S Mummolo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Vickers Microhardness ◽  
Flexural Modulus ◽  
Bending Test ◽  
Resin Composites ◽  
Three Point Bending ◽  
Main Effect ◽  
Dependent Variables ◽  
Marginal Means

SUMMARY The aim of this study was to assess the flexural strength, flexural elastic modulus and Vickers microhardness of three resin composites prepared at room temperature or cured after one or repeated preheating cycles to a temperature of 39°C. Three resin composites were evaluated: Enamel Plus HFO (Micerium), Opallis (FGM), and Ceram X Duo (Dentsply DeTrey). For each trial, one group of specimens of each material was fabricated under ambient laboratory conditions, whereas in the other groups, the composites were cured after 1, 10, 20, 30, or 40 preheating cycles to a temperature of 39°C in a preheating device. Ten rectangular prismatic specimens (25 × 2 × 2 mm) were prepared for each group (N=180; n=10) and subjected to a three-point bending test for flexural strength and flexural modulus evaluation. Vickers microhardness was assessed on 10 cylindrical specimens from each group (N=180; n=10). Statistical analysis showed that, regardless of the material, the number of heating cycles was not a significant factor and was unable to influence the three mechanical properties tested. However, a significant main effect of the employed material on the marginal means of the three dependent variables was detected.

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 grinding procedures on the flexural strength of zirconia ceramics

2010 ◽  
Vol 21 (6) ◽  
pp. 528-532 ◽  
Author(s):  
Ufuk İşerı ◽  
Zeynep Özkurt ◽  
Ender Kazazoğlu ◽  
Davut Küçükoğlu
Keyword(s):  
Flexural Strength ◽  
High Speed ◽  
Testing Machine ◽  
Fracture Load ◽  
Bending Test ◽  
Control Group ◽  
Zirconia Ceramics ◽  
Significance Level ◽  
Universal Testing ◽  
Short Time

The surface of zirconia may be damaged during grinding, influencing the mechanical properties of the material. The purpose of this study was to compare the flexural strength of zirconia after different grinding procedures. Twenty bar-type zirconia specimens (21 x 5 x 2 mm) were divided into 4 groups and ground using a high-speed handpiece or a low-speed straight handpiece until the bars were reduced 1 mm using two different grinding times: continuous grinding and short-time grinding (n=5). Control specimens (n=5) were analyzed without grinding. The flexural strengths of the bars were determined by using 3-point bending test in a universal testing machine at a crosshead speed of 0.5 mm/min. The fracture load (N) was recorded, and the data were analyzed statistically by the Kruskal Wallis test at a significance level of 0.05. In the test groups, high-speed handpiece grinding for a short time had produced the highest mean flexural strength (878.5 ± 194.8 MPa), while micromotor continuous grinding produced the lowest mean flexural strength (733.8 ± 94.2 MPa). The control group was the strongest group (928.4 ± 186.5 MPa). However, there was no statistically significant differences among the groups (p>0.05). Within the limitations of the study, there was no difference in flexural strength of zirconia specimens ground with different procedures.

scholarly journals Flexural Strength and Depth of Cure of Single Shade Dental Composites

2021 ◽  
pp. 110-118
Author(s):  
Fatin A. Hasanain
Keyword(s):  
Flexural Strength ◽  
Testing Machine ◽  
Dental Composites ◽  
Resin Composites ◽  
Dental Resin ◽  
Depth Of Cure ◽  
Universal Testing ◽  
Significant Difference ◽  
Experimental Laboratory ◽  
Cylindrical Samples

Aims: This work aims to assess the flexural strength and depth of cure of Optishade, Omnichroma and Z350 dental resin composites. Study Design: Experimental Laboratory Study. Methods: To assess flexural strength as per ISO standards, 15 samples of each of the three materials were made (n=5) with the dimensions 25x2x2 mm. They were then subjected to 3 point bending testing on a universal testing machine. To assess depth of cure as per ISO standard, 15 cylindrical samples 4 mm in diameter and 6 mm in height were created (n=5) and scraping test was performed. Results: There was a significant difference between the 3 materials in both flexural strength and depth of cure. Z350 had the lowest depth of cure and the highest flexural strength. Conclusion: Within the limitations of this study, all three tested materials fell within the ISO requirementsfor dental resin compositesfor both flexural strength and depth of cure.

scholarly journals Flexural Strength of Composite Based Provisional Crown Materials

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.

Fabrication of High Strength α-SiAlON/BN Composition Ceramics by Hot Pressing

2012 ◽  
Vol 512-515 ◽  
pp. 816-819 ◽  
Author(s):  
Ying Chun Shan ◽  
Guang Wang ◽  
Hui Ye ◽  
Xiao Guang Han ◽  
Jiu Jun Xu ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Room Temperature ◽  
High Strength ◽  
Bending Test ◽  
Composite Ceramics ◽  
Major Phase ◽  
Three Point Bending ◽  
Powder Body

Dense Y3+-dopted α-SiAlON/BN composition ceramics was fabricated by hot pressing at 1900 °C for 60 min, and flextural strength at room and 1000 °C was investigated through three-point bending test. The results show that h-BN contribute to the densification of powder body, but h-BN have little affect on the key temperature region of sintering densification of α-SiAlON ceramics. When content of BN is lower, which didn’t affect on the phase transformation of α-SiAlON, but when content of BN is higher, besides of major phase α-SiAlON, a little of β-SiAlON was also formed. For the α-SiAlON/BN composite ceramics content of 20 wt.% h-BN, the higer flexural strength( room-temperature and 1000 °C) were abtained, the formation of β-SiAlON should be an important resonon for the higher strentgh, more important is , whose flexural strength at 1000 °C is higher 50 MPa than at room temperature, the differnce of thermal properties between SiAlON and BN should contribute to the improve of high-temperature flextural strength.

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