Effect of Preheating on the Mechanical Properties of Resin Composites

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)

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

Operative Dentistry ◽

10.2341/13-238-l ◽

2015 ◽

Vol 40 (2) ◽

pp. 181-189 ◽

Cited By ~ 6

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.

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Influence of Concentrations of Methacrylate and Acrylate Monomers on the Properties of Fiber Reinforced Polymethyl Methacrylate Denture Base Materials

Acta Chemica Iasi ◽

10.2478/achi-2018-0020 ◽

2018 ◽

Vol 26 (2) ◽

pp. 329-350 ◽

Cited By ~ 2

Author(s):

Faik Tugut ◽

Mehmet Turgut ◽

Dursun Saraydin

Keyword(s):

Mechanical Properties ◽

Impact Strength ◽

Testing Machine ◽

Weight Ratio ◽

Acrylic Resin ◽

Bending Test ◽

Control Group ◽

Test Machine ◽

Fiber Reinforced ◽

Significant Difference

Abstract The study aimed to evaluate the effects of adding different concentrations of 2 hydroxyethyl methacrylate (HEMA), 2-hydroxyethyl acrylate (HEA), ethyl methacrylate (EA) and isobutyl methacrylate (IBMA) monomers on the structural, thermal and mechanical properties of a fiber reinforced heat-polymerized acrylic resin. For each test, 126 acrylic resin specimens were fabricated and divided into 6 groups with 7 specimens each. One group was the control group, the other one is a fiber reinforced group and others were the test groups, which were formed according to the different concentrations of monomers. 6 mm length, and the weight ratio of 3% short glass fibers are added to acrylic powder polymerized by heating. The 2%, 5%, 10%, at 20 % ratios of different comonomers added to a monomer of MMA are composed of copolymer structures. Flexural strength was assessed with a three-point bending test using a universal testing machine. Impact strength testing was conducted using an impact test machine by the Charpy method. The analysis of the connection between acrylic resin and fiber by SEM and structural changes in the acrylic resin was investigated by FTIR spectroscopy. Data analyses using analysis of Kruskal-Wallis and Mann-Whitney U tests (α=0.05) significant difference tests showed that adding 2%, 5% HEMA and IBMA monomers significantly increased the flexural and impact strength compared to the control, only fiber and others group (P< 0.05). It is observed that the process of adding low concentration of HEMA and IBMA monomers improved certain mechanical properties of fiber reinforced with polymethylmethacrylate.

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Effect of Filler Content and Waiting time Before Light-Curing on Mechanical Properties of Dual-Cured Cement

Current Dentistry ◽

10.2174/2542579x01666190924180448 ◽

2020 ◽

Vol 2 (1) ◽

pp. 45-52

Author(s):

Ana C. de Assunção Oliveira ◽

Sandro Griza ◽

Rafael R. de Moraes ◽

André L. Faria-e-Silva

Keyword(s):

Mechanical Properties ◽

Elastic Modulus ◽

Flexural Strength ◽

Waiting Time ◽

Filler Content ◽

Bending Test ◽

Resin Cements ◽

Three Point Bending ◽

Light Curing ◽

Curing Procedure

Objective:: To investigate the effect of filler content and the time spent before light-curing on mechanical properties of dual-cured cement. Methods:: Experimental dual-cured resin cements were formulated with 60, 65 or 68wt% of filler. The viscosity of experimental cement was measured using a digital viscometer. Bar-shaped specimens (25 x 2 x 2 mm) were fabricated, while the light-curing was started immediately or 5 minutes after the insertion of cement into the mold (n = 7). A three-point bending test was performed and the values of flexural strength and elastic modulus were measured. The Vickers hardness of fractured specimens was measured on the surface of the cement. Data from viscosity were submitted to oneway ANOVA, while the data from mechanical properties were analyzed by two-way ANOVA. All pair-wise comparisons were performed using Tukey’s test (α = 0.05). Results:: The experimental cement with 68wt% of filler showed the highest viscosity and those with 60wt% showed the the lowest viscosity. Irrespective of the time spent before light-curing, the cement with 65wt% of filler presented the highest values of flexural strength and elastic modulus. The addition of 60wt% of filler resulted in the lowest elastic modulus, while 68wt% of filler resulted in lowest flexural strength. Regarding the hardness, the cement with 68wt% of filler showed the highest values, while there was no difference between 60 and 65wt% of filler. Conclusion:: Filler content affected the mechanical properties of the experimental cement and this effect did not depend on the waiting time before the light-curing procedure.

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Evaluation of the Loading, Unloading, and Permanent Deformation of Newly Available Epoxy Resin Coated Ni-Ti Wires Using Self-Ligating Brackets

International Journal of Dentistry ◽

10.1155/2017/8085067 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8

Author(s):

Hazel Garro-Piña ◽

María Cristina Jiménez-Cervantes ◽

Ricardo Ondarza-Rovira ◽

Roberto Justus ◽

Salvador García-López

Keyword(s):

Mechanical Properties ◽

Epoxy Resin ◽

Clinical Management ◽

Permanent Deformation ◽

Applied Force ◽

Bending Test ◽

Recovery Cycle ◽

Three Point Bending ◽

Significant Difference

Aim. The purpose of this study was to evaluate the load and unload deflection and permanent deformation of round 0.016′′ and rectangular 0.016′′×0.022′′ regular and coated Ni-Ti wires. Materials and Methods. Ni-Ti archwires produced by two manufacturers were evaluated. Both regular and coated round and rectangular Ni-Ti wire segments (n=15) from each group were submitted to a three-point bending test. Both types of wires were evaluated for permanent deformation at the end of a recovery cycle. Results. The coated round 0.016′′ Ni-Ti wires produced a significantly lower force in loading (p<0.01) and unloading (p<0.01) than regular wires of the same manufacturer and size. There was no significant difference in permanent deformation between coated and regular round Ni-Ti wires from the same company. For rectangular 0.016×0.022′′ Ni-Ti wires, there was a significant difference in the loading evaluation, but the unloading test presented no significant differences. The permanent deformation of the rectangular wires revealed no significant difference between them. Conclusion. The addition of an esthetic coating to these new Ni-Ti wires produced changes in their mechanical properties, manifested as a reduction in the applied force, which should be considered in clinical management.

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Rapid 3 s Curing: What Happens in Deep Layers of New Bulk-Fill Composites?

Materials ◽

10.3390/ma14030515 ◽

2021 ◽

Vol 14 (3) ◽

pp. 515

Author(s):

Danijela Marovic ◽

Matej Par ◽

Ana Crnadak ◽

Andjelina Sekelja ◽

Visnja Negovetic Mandic ◽

...

Keyword(s):

Mechanical Properties ◽

Raman Spectroscopy ◽

Flexural Strength ◽

Flexural Modulus ◽

Degree Of Conversion ◽

Resin Composites ◽

Three Point Bending ◽

Deep Layers ◽

Light Curing ◽

New Generation

This study assessed the influence of rapid 3 s light curing on the new generation of bulk-fill resin composites under the simulated aging challenge and depths up to 4 mm. Four bulk-fill materials were tested: two materials designed for rapid curing (Tetric PowerFill—PFILL; Tetric PowerFlow—PFLW) and two regular materials (Filtek One Bulk Fill Restorative—FIL; SDR Plus Bulk Fill Flowable—SDR). Three-point bending (n = 10) was used to measure flexural strength (FS) and flexural modulus (FM). In the 3 s group, two 2 mm thick specimens were stacked to obtain 4 mm thickness, while 2 mm-thick specimens were used for ISO group. Specimens were aged for 1, 30, or 30 + 3 days in ethanol. The degree of conversion (DC) up to 4 mm was measured by Raman spectroscopy. There was no difference between curing protocols in FS after 1 day for all materials except PFLW. FM was higher for all materials for ISO curing protocol. Mechanical properties deteriorated by increasing depth (2–4 mm) and aging. ISO curing induced higher DC for PFLW and FIL, while 3 s curing was sufficient for PFILL and SDR. The 3 s curing negatively affected FM of all tested materials, whereas its influence on FS and DC was highly material-specific.

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Influence of Al2O3 as Filler Loading on the Fracture Toughness of Light-Cured Dental Resin Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.816-817.227 ◽

2013 ◽

Vol 816-817 ◽

pp. 227-231 ◽

Cited By ~ 3

Author(s):

Saad Omar Alsharif ◽

Hazizan Md Akil ◽

Nasser Abbas Abd El-Aziz ◽

Zainal Arifin Bin Ahmad

Keyword(s):

Fracture Toughness ◽

Filler Loading ◽

Bending Test ◽

Resin Composites ◽

Dental Resin ◽

Notched Specimen ◽

Three Point Bending ◽

Dental Resin Composites ◽

Significant Difference ◽

Composite Samples

The purpose of the present study was to evaluate the effect of filler loading on the fracture toughness of light-cured dental resin composites (DRCs). The monomer Bis-GMA and TEGDMA (75/25 wt/wt) were mixed with treated micro-sized aluminum oxide (Al2O3) particles ranging from 40-60 wt% as filler. The composite samples were cured with LED for 80s. The bulk density (g/cm3) and apparent porosity (%) of the samples were determined according to the ASTM standard. The fracture toughness (KIC) values of the composites were determined using a single edge notched specimen in the three-point bending test. There was a significant difference in KICof the composites with different loading of Al2O3particles (p< 0.05). The highest amount of filler (60 wt%) reduced the KICvalue to 1.5 MPa.m1/2. As a conclusion, the Al2O3particles used as filler loading does have an effect on the mechanical properties of DRCs.

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PENGARUH POSISI SERAT KACA (FIBERGLASS) YANG BERBEDA TERHADAP KEKUATAN FLEKSURAL FIBER REINFORCED ACRYLIC RESIN

ODONTO Dental Journal ◽

10.30659/odj.3.2.128-132 ◽

2016 ◽

Vol 3 (2) ◽

pp. 128

Author(s):

Aprilia Dian Fatimina ◽

Benni Benyamin ◽

Helmi Fathurrahman

Keyword(s):

Acrylic Resin ◽

Bending Test ◽

Control Group ◽

Fiber Reinforced ◽

Three Point Bending ◽

Significant Difference ◽

Bottom Side ◽

Group 3 ◽

Post Hoc

Background: One of factor that increases the flexural strenght of fiberreinforced acrylic resin is a fiberglass position . Fiberglass is one of type that can be used in dentistry. The aim of this was to determine the influence of position of fiberglass to the flexural strenght of fiber reinforced acrylic resin.Method: This study was in vitro laboratory experimental. Samples was 16plate spesimens (65x10x2.5mm). The study group was divided into 4 group : 3 groups of fiber reinforced acrylic resin were given fiberglass at the upper, middle, and bottom side and 1 control group of resin acrylic without fiberglass. All of groups would be in the flexural strenght test with a three-point bending test using a universal testing machine.Result: Based on One Way ANOVA test showed that there were significantvalue 0.000 (p<0.05), it concluded that there were significant influencebetween all the groups. Based on the LSD Post Hoc test showed that therewere significant value between all of groups with fiberglass reinforced andcontrol group without fiberglass reinforced. Comparisson between the group that given fiberglass in a upper and middle side with the group that given in bottom side showed value of significant difference (p < 0.05).Conclusion: The result of study was concluded that there was an influenceon the position of fiberglass to flexural strenght of fiber reinforced acrylic resin

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