Simple and Low-Cost Thermal Treatments on Direct Resin Composites for Indirect Use

Abstract The aim of this study was to evaluate the influence of three low-cost additional thermal treatments, available in the dental office, on the mechanical, chemical and optical properties of a light-cured resin composite indicated for direct restorations but used as indirect restorative. The direct resin composite TPH3 (Dentsply) was light-polymerized using a light-emitting diode curing unit and submitted to three experimental additional thermal treatments: dry heat at 170 °C for 5 min, autoclave at 121 °C for 6 min, or microwave oven at 450 W for 3 min. The resin composite without any thermal treatment was used as negative control group. An indirect resin composite (Vita CM LC, Vita Zahnfabrik) was tested as a reference. Flexural strength, elastic modulus, microhardness, degree of C=C conversion, roughness before and after simulated toothbrush abrasion, translucency parameter and color difference (ΔE00) were evaluated. Data were analyzed at α=0.05. The indirect resin composite presented lower C=C conversion and mechanical performance. The flexural strength was significantly higher in the dry oven group compared with the control. The roughness was not different among groups before or after brushing, but the thermal treatments caused an increase in C=C conversion, microhardness, and elastic modulus without affecting the translucency parameter or showing visible color alteration (ΔE00<1.8). These results suggest that the use of additional thermal methods of polymerization represents an economical and simple alternative to enhance the mechanical and chemical properties of direct resin composites when used as indirect restoratives.

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Polymerization Behavior and Mechanical Properties of High-Viscosity Bulk Fill and Low Shrinkage Resin Composites

Operative Dentistry ◽

10.2341/16-385-l ◽

2017 ◽

Vol 42 (6) ◽

pp. E177-E187 ◽

Cited By ~ 9

Author(s):

S Shibasaki ◽

T Takamizawa ◽

K Nojiri ◽

A Imai ◽

A Tsujimoto ◽

...

Keyword(s):

Mechanical Properties ◽

Elastic Modulus ◽

Flexural Strength ◽

Resin Composite ◽

High Viscosity ◽

The Other ◽

Light Irradiation ◽

Volumetric Shrinkage ◽

Resin Composites ◽

Polymerization Shrinkage

SUMMARY The present study determined the mechanical properties and volumetric polymerization shrinkage of different categories of resin composite. Three high viscosity bulk fill resin composites were tested: Tetric EvoCeram Bulk Fill (TB, Ivoclar Vivadent), Filtek Bulk Fill posterior restorative (FB, 3M ESPE), and Sonic Fill (SF, Kerr Corp). Two low-shrinkage resin composites, Kalore (KL, GC Corp) and Filtek LS Posterior (LS, 3M ESPE), were used. Three conventional resin composites, Herculite Ultra (HU, Kerr Corp), Estelite ∑ Quick (EQ, Tokuyama Dental), and Filtek Supreme Ultra (SU, 3M ESPE), were used as comparison materials. Following ISO Specification 4049, six specimens for each resin composite were used to determine flexural strength, elastic modulus, and resilience. Volumetric polymerization shrinkage was determined using a water-filled dilatometer. Data were evaluated using analysis of variance followed by Tukey's honestly significant difference test (α=0.05). The flexural strength of the resin composites ranged from 115.4 to 148.1 MPa, the elastic modulus ranged from 5.6 to 13.4 GPa, and the resilience ranged from 0.70 to 1.0 MJ/m3. There were significant differences in flexural properties between the materials but no clear outliers. Volumetric changes as a function of time over a duration of 180 seconds depended on the type of resin composite. However, for all the resin composites, apart from LS, volumetric shrinkage began soon after the start of light irradiation, and a rapid decrease in volume during light irradiation followed by a slower decrease was observed. The low shrinkage resin composites KL and LS showed significantly lower volumetric shrinkage than the other tested materials at the measuring point of 180 seconds. In contrast, the three bulk fill resin composites showed higher volumetric change than the other resin composites. The findings from this study provide clinicians with valuable information regarding the mechanical properties and polymerization kinetics of these categories of current resin composite.

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Evaluation of the Sealing Ability of Three Obturation Techniques Using a Glucose Leakage Test

BioMed Research International ◽

10.1155/2017/2704094 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Katarzyna Olczak ◽

Halina Pawlicka

Keyword(s):

Continuous Wave ◽

Negative Control Group ◽

Positive Control ◽

Negative Control ◽

Control Group ◽

Thermal Methods ◽

Root Canals ◽

Anterior Teeth ◽

Sealing Ability ◽

Significant Difference

The aim of this study was to evaluate the sealing ability of three different canal filling techniques. Sixty-four roots of extracted human maxillary anterior teeth were prepared using ProTaper® rotary instruments. The specimens were then randomly divided into 3 experimental groups (n=16) and 2 control groups (n=8). The root canals were filled using cold lateral compaction (CLC group), continuous wave condensation technique using the Elements Obturation Unit® (EOU group), and ProTaper obturators (PT group). For the negative control group, 8 roots were filled using lateral compaction as in the CLC group, and the teeth were covered twice with a layer of nail varnish (NCG group). Another 8 roots were filled using lateral compaction, but without sealer, and these were used as the positive control (PCG group). A glucose leakage model was used for quantitative evaluation of microleakage for 24 hours and 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 weeks. No significant difference in the cumulative amount of leakage was found between the three experimental groups at all observation times. The lateral condensation of cold gutta-percha can guarantee a similar seal of canal fillings as can be achieved by using thermal methods, in the round canals.

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Influence of Different Concentration and Ratio of a Photoinitiator System on the Properties of Experimental Resin Composites

Brazilian Dental Journal ◽

10.1590/0103-6440201701372 ◽

2017 ◽

Vol 28 (6) ◽

pp. 726-730 ◽

Cited By ~ 5

Author(s):

Caio Vinícius Signorelli Grohmann ◽

Eveline Freitas Soares ◽

Eduardo José Carvalho Souza-Junior ◽

William Cunha Brandt ◽

Regina Maria Puppin-Rontani ◽

...

Keyword(s):

Mechanical Properties ◽

Elastic Modulus ◽

Flexural Strength ◽

Tertiary Amine ◽

Water Sorption ◽

Water Solubility ◽

Distilled Water ◽

Resin Composites ◽

Amine Concentration ◽

One Way Anova

Abstract The aim in this study was to evaluate the influence of different ratio of camphorquinone/tertiary amine concentration on the flexural strength (FS), elastic modulus (EM), degree of conversion (DC), yellowing (YL), water sorption (WS) and water solubility (WSL) of experimental composites. Thus, acrylate blends were prepared with different camphorquinone (CQ) and amine (DABE) concentrations and ratios by weight: (CQ/DABE%): 0.4/0.4% (C1), 0.4/0.8% (C2), 0.6/0.6% (C3), 0.6/1.2% (C4), 0.8/0.8% (C5), 0.8/1.6% (C6), 1.0/1.0% (C7), 1.0/2.0% (C8), 1.5/1.5% (C9), 1.5/3.0% (C10). For the FS and EM, rectangular specimens (7x2x1 mm, n=10) were photo-activated by single-peak LED for 20 s and tested at Instron (0.5 mm/min). Then, the same specimens were evaluated by FTIR for DC measurement. For YL, disks (5x2 mm, n=10) were prepared, light-cured for 20 s and evaluated in spectrophotometer using the b aspect of the CIEL*a*b* system. For WS and WSL, the volume of the samples was calculated (mm³). For WS and WSL, composites disks (5x0.5 mm, n=5) were prepared. After desiccation, the specimens were stored in distilled water for 7 days and again desiccated, in order to measure the WS and WSL. Data were submitted to one-way ANOVA and Tukey’s test (5%). The groups C8, C9 and C10 showed higher DC, EM and YL means, compared to other composites. Therefore, the FS and WS values were similar among all groups. Also, C1, C2 and C3 presented higher WSL in 7 days, compared to other composites. In general, higher concentrations of camphorquinone promoted higher physical-mechanical properties; however, inducing higher yellowing effect for the experimental composites

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

BioMed Research International ◽

10.1155/2019/5109481 ◽

2019 ◽

Vol 2019 ◽

pp. 1-8 ◽

Cited By ~ 16

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.

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Time-dependent nanoindentation behavior of high elastic modulus dental resin composites

Journal of Materials Research ◽

10.1557/jmr.2010.0070 ◽

2010 ◽

Vol 25 (3) ◽

pp. 529-536 ◽

Cited By ~ 4

Author(s):

Yijun Wang ◽

Isabel K. Lloyd

Keyword(s):

Elastic Modulus ◽

Volume Fraction ◽

Resin Composite ◽

Acrylic Resin ◽

Resin Matrix ◽

Resin Composites ◽

Dental Resin ◽

Elastic Plastic ◽

High Elastic Modulus ◽

Continuous Stiffness Measurement

Nanoindentation and the viscous-elastic–plastic (VEP) model developed by Oyen and Cook for lightly filled thermoplastic polymer composites were used to characterize the elastic modulus, hardness, and viscoelastic response of a new high elastic modulus dental resin composite. The VEP model was used because loading rate studies indicated a viscous component in the loading/unloading response of our highly filled, thermosetting acrylic resin composites. Increasing the volume fraction of our high modulus filler increased the elastic modulus and hardness and decreased the viscous response in our composites. Coupling the filler and resin matrix with a commercial coupling agent like Metaltite or MPTMS (3-methacryloxypropyltrimethoxysilane) that ionically bonds to the filler and covalently bonds to the matrix decreases the viscous response and increases the hardness of the composite. The coupling agents did not affect the elastic modulus. The ability of the VEP model to predict load–displacement trajectories and the correlation of the elastic modulus and hardness values determined from the VEP model with those from the direct continuous stiffness measurement mode nanoindentation measurements indicate that the VEP model can be extended to highly filled, thermosetting systems. This is valuable since the potential to predict elastic, plastic, and viscous contributions to behavior should be valuable in the design and understanding of future highly filled resin composite systems.

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Effect of Low Shrinkage Monomers on Physicochemical Properties of Dental Resin Composites

Brazilian Dental Journal ◽

10.1590/0103-6440201300401 ◽

2015 ◽

Vol 26 (3) ◽

pp. 272-276 ◽

Cited By ~ 5

Author(s):

Dayane Carvalho Ramos Salles de Oliveira ◽

Karla Rovaris ◽

Viviane Hass ◽

Eduardo José Souza-Júnior ◽

Francisco Haiter-Neto ◽

...

Keyword(s):

Flexural Strength ◽

Physicochemical Properties ◽

Statistical Difference ◽

Resin Composite ◽

Multiple Comparisons ◽

Resin Composites ◽

Dental Resin ◽

Tukey Test ◽

Dental Resin Composites ◽

One Way Anova

The aim of this study was to evaluate the effect of low shrinkage monomers on physicochemical properties of dental resin composites. Two low shrinkage resin composites: one with a crosslink branching monomer (Kalore, GC Corp) and a novel monomer (Venus Diamond, Heraeus Kulzer) were compared to a conventional resin composite formulation (Filtek Z250, 3M/ESPE). The volumetric shrinkage was evaluated by µCT analysis (n=5) and the physicochemical properties by degree of C=C conversion (DC), flexural strength (FS) and Young's modulus (YM) (n=10). All samples were light cured by a LED device (Radii, SDI) with 16 J/cm2. The results were analysed by one-way ANOVA and Tukey test for multiple comparisons (α=0.05). No statistical difference was found between µCT shrinkage values to Kalore (1.8%) and Venus Diamond (1.7%) (p≥0.05); Z250 presented statistical highest shrinkage value (2.0%). Kalore presented higher statistical DC (60.8%) than Venus Diamond (49.5%) and Z250 (49.6%). No statistical difference was found between FS or YM properties to Venus Diamond and Z250; Kalore presented statistical lowest FS and YM properties (p≥0.05). Conclusion: Using novel monomers seem to reduce polymerization shrinkage without affecting the physicochemical properties evaluated of resin composites rather than using crosslink branching monomers.

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Shear Bond Strength and Optical Properties of Resin Composite - Layered Provisional Poly(methyl methacrylate) (PMMA)

The Open Dentistry Journal ◽

10.2174/1874210602115010176 ◽

2021 ◽

Vol 15 (1) ◽

pp. 176-183

Author(s):

Juthatip Aksornmuang ◽

Juckrapun Tiangtrong

Keyword(s):

Optical Properties ◽

Bond Strength ◽

Methyl Methacrylate ◽

Shear Bond Strength ◽

Resin Composite ◽

Bonding Agent ◽

Control Group ◽

Resin Composites ◽

Poly Methyl Methacrylate ◽

Pmma Surface

Aims: To compare the shear bond strength between resin composite and Poly(methyl methacrylate) (PMMA) with various bonding protocols and to evaluate the optical properties of resin composite - layered provisional Poly(methyl methacrylate) (PMMA). Materials and Methods: Eighty cylindrical shape specimens were fabricated from self-polymerized provisional Poly(methyl methacrylate) (PMMA) and they were randomly divided into eight groups. Poly(methyl methacrylate) (PMMA) was mixed and bonded onto the specimens as a positive control group. Resin composite was bonded to MMA-wetted surface without bonding agent as a negative control group. All remaining groups were bonded to resin composite using different bonding agents (Scothbond Universal, Luxatemp glaze&bond, and HC Primer) with and without MMA wetting. Shear bond strength testing was performed using a universal testing machine. Various shades of 0.5 mm-thick resin composites were layered onto 1.5 mm-thick PMMA both light and dark shade, with the most effective bonding protocol. Color differences between resin composite and – layered provisional Poly(methyl methacrylate) (PMMA) were measured using Spectrophotometer. Results: Bonding resin composite onto Poly(methyl methacrylate) (PMMA) using luxatemp glaze, bond and HC Primer without methyl methacrylate wetting provided statistically significantly lower bond strength than those of the MMA-wetted Poly(methyl methacrylate) (PMMA) surface. The highest shear bond strength was achieved with the application of Scothbond Universal Adhesive regardless of MMA wetting. The colors of resin composite - layered provisional Poly(methyl methacrylate) (PMMA) were different from the original resin composite color with ΔE results greater than the acceptable threshold (>3.7). Conclusion: Resin composites were able to effectively bond to the MMA-wetted Poly(methyl methacrylate) (PMMA) surface with the application of a tested bonding agent. Layering Poly(methyl methacrylate) (PMMA) with 0.5 mm-thick resin composite could not modify the Poly(methyl methacrylate) (PMMA) shade to the original resin composite color.

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Effects of SiO2 Incorporation on the Flexural Properties of a Denture Base Resin: An In Vitro Study

European Journal of Dentistry ◽

10.1055/s-0041-1732806 ◽

2021 ◽

Author(s):

Sara T. Alzayyat ◽

Ghadah A. Almutiri ◽

Jawhara K. Aljandan ◽

Raneem M. Algarzai ◽

Soban Q. Khan ◽

...

Keyword(s):

Elastic Modulus ◽

Flexural Strength ◽

Testing Machine ◽

Base Material ◽

Bending Test ◽

Control Group ◽

Denture Base ◽

Nano Sio2 ◽

Base Resin ◽

Denture Base Resin

Abstract Objective The aim of this study was to evaluate the effects of the addition of low-silicon dioxide nanoparticles (nano-SiO2) on the flexural strength and elastic modulus of polymethyl methacrylate (PMMA) denture base material. Materials and Methods A total of 50 rectangular acrylic specimens (65 × 10 × 2.5 mm3) were fabricated from heat-polymerized acrylic resin. In accordance with the amount of nano-SiO2, specimens were divided into the following five groups (n = 10 per group): a control group with no added SiO2, and four test groups modified with 0.05, 0.25, 0.5, and 1.0 wt% nano-SiO2 of acrylic powder. Flexural strength and elastic modulus were measured by using a 3-point bending test with a universal testing machine. A scanning electron microscope was used for fracture surface analyses. Data analyses were conducted through analysis of variance and Tukey’s post hoc test (α = 0.05). Results Compared with the control group, flexural strength and modulus of elasticity tended to significantly increase (p ˂ 0.001) with the incorporation of nano-SiO2. In between the reinforced groups, the flexural strength significantly decreased (p ˂ 0.001) as the concentrations increased from 0.25 to 1.0%, with the 1.0% group showing the lowest value. Furthermore, the elastic modulus significantly increased (p ˂ 0.001) at 0.05% followed by 1.0%, 0.25%, 0.5%, and least in control group. Conclusion A low nano-SiO2 addition increased the flexural strength and elastic modulus of a PMMA denture base resin.

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Chemical and Mechanical Properties of Experimental Dental Composites as a Function of Formulation and Postcuring Thermal Treatment

BioMed Research International ◽

10.1155/2018/9845427 ◽

2018 ◽

Vol 2018 ◽

pp. 1-6 ◽

Cited By ~ 6

Author(s):

Renata A. Esteves ◽

Letícia C. C. Boaro ◽

Flávia Gonçalves ◽

Luiza M. P. Campos ◽

Cecy M. Silva ◽

...

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Elastic Modulus ◽

Thermal Treatment ◽

Flexural Strength ◽

Low Cost ◽

Chemical Properties ◽

Degree Of Conversion ◽

Dental Composites ◽

Molar Ratios

This study evaluated the influence of formulation and thermal treatment on the degree of conversion, fracture toughness, flexural strength, and elastic modulus of experimental composites. Six composites were analyzed at BisGMA : TEGDMA molar ratios of 1 : 1 and 7 : 3 with filler at 30, 50, and 70 wt%. The degree of conversion was analyzed by Fourier transform infrared spectroscopy, fracture toughness was measured using the single-edge notched beam, and flexural strength and elastic modulus were measured with the 3-point bend test. For all tests, one-half of the specimens received thermal treatment at 170°C for 10 min. Data were analyzed by the Kruskal-Wallis or ANOVA/Tukey’s test (α = 5%). The 1 : 1 BisGMA : TEGDMA ratio showed higher properties than the 7 : 3 ratio. Although the material with 70% filler had a conversion lower than the one with 50%, it showed higher mechanical properties. The thermal treatment improved all properties in all materials. Therefore, the use of an equimolar ratio of BisGMA : TEGDMA can be paired with 70 wt% filler to design dental composites that possess increased advantageous physical and chemical properties. Furthermore, the simple and low-cost method of thermal treatment proposed for use in clinical dentistry has been shown to effectively improve the properties of all evaluated materials.

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The effect of radiation exposure and storage time on the degree of conversion and flexural strength of different resin composites

Bulletin of the National Research Centre ◽

10.1186/s42269-021-00605-y ◽

2021 ◽

Vol 45 (1) ◽

Author(s):

Ragia M. Taher ◽

Lamiaa M. Moharam ◽

Amin E. Amin ◽

Mohamed H. Zaazou ◽

Farid S. El-Askary ◽

...

Keyword(s):

Flexural Strength ◽

Radiation Exposure ◽

Storage Time ◽

Resin Composite ◽

Degree Of Conversion ◽

Bending Test ◽

Resin Composites ◽

Significant Difference ◽

Infrared Spectrometer ◽

And Storage

Abstract Background This study was conducted to evaluate the effect of radiation exposure and storage time on the degree of conversion (DC%) and flexural strength (FS) of three different resin composites. In total, 90 disk-shaped, and 360 rod-shaped composite specimens were prepared to evaluate the DC% and FS, respectively. Specimens were divided into 18 groups (DC%: n = 5 and FS: n = 20) according to the three experimental factors of the study: 1—Radiation (no-exposure and exposure), 2—Resin composite material (Herculite XRV Ultra, Z250 XT and Grandio), and 3—Storage time (24 h in distilled water, 3-m and 6-m in 70% ethanol). Fourier transform infrared spectrometer (FTIR) was used to determine the DC%. For FS, the specimens were subjected to a three-point bending test at 1 mm/min crosshead speed. Data were analyzed using three-way ANOVA/Tukey HSD test. Significant level was set at P = 0.05. Results For DC%, there was no significant difference between no-radiation exposure and radiation exposure (P > 0.05). Herculite XRV Ultra revealed the highest statistically significant DC% (P < 0.05). The 24-h storage time revealed the least significant DC% (P < 0.05). For FS, radiation exposure showed a statistically significant higher value compared to no-radiation exposure (P < 0.05). Herculite XRV Ultra showed the least FS value (P < 0.05). The 24-h storage time showed the highest significant value (P < 0.05). Conclusions Radiation exposure has no significant impact on the DC% of the different resin composites, but it has a significant positive effect on the FS. Storage time had a significant effect on both DC% and FS.

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