A Comparative Study of the Mechanical Properties of Selected Dental Composites with a Dual-Curing System with Light-Curing Composites

Dual-curing composites have a wide spectrum of use in practice (rebuilding, reconstruction, and luting). The characterization of this type of material and comparative study of selected mechanical properties with light-cured materials were carried out for this paper. In this study, we used six materials with a dual-cure system—Bulk EZ, Fill-Up!, StarFill 2B, Rebilda DC, MultiCore Flow, Activa Bioactive-Restorative—and three light-cured materials—Filtek Bulk Fill Posterior, Charisma Classic, and G-aenial Universal Flo. The materials were conditioned for 24 h in water at 37 °C before testing. Selected material properties were determined: three-point bending flexural strength, diametral tensile strength, hardness, microhardness, and shrinkage stress. The highest three-point bending flexural strength (TPB) was 137.0 MPa (G-aenial Universal Flo), while the lowest amounted to 86.5 MPa (Activa Bioactive). The diametral tensile strength (DTS) values were in a range from 39.2 MPa (Rebilda DC) to 54.1 MPa (Charisma Classic). The lowest hardness (HV) value of 26 was obtained by the Activa Bioactive material, while the highest values were recorded for Filtek Bulk Fill Posterior and Charisma Classic-53. The shrinkage stress of the tested materials ranged from 6.3 MPa (Charisma Classic) to 13.2 MPa (G-aenial Universal Flo). Dual-curing composites were found to have similar properties to light-cured composites.

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Influence of Ketones on Selected Mechanical Properties of Resin Composites

Journal of Dental Research ◽

10.1177/00220345920710111601 ◽

1992 ◽

Vol 71 (11) ◽

pp. 1847-1850 ◽

Cited By ~ 24

Author(s):

A. Peutzfeldt ◽

E. Asmussen

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Flexural Strength ◽

Modulus Of Elasticity ◽

Cross Linking ◽

Resin Composites ◽

Light Curing ◽

Resistance To Wear ◽

Modulus Of Resilience ◽

Diametral Tensile Strength

The present study investigated a concept for additional crosslinking of dental polymers, by which resistance to wear of resin composites might be increased. Bifunctional ketones were added to monomer mixtures, which were then made light-curing and loaded with filler. The monomer mixtures were varied with respect to type and ratio of monomer and ketone. For measurement of possible effects of the cross-linking agents added, four mechanical properties of the experimental resin composites were determined. Addition of the bifunctional ketone diacetyl resulted in the following increases in mechanical properties: diametral tensile strength, 11%; flexural strength, 29%; modulus of elasticity, 19%; and modulus of resilience, 50%.

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The influence of filler amount on selected properties of new experimental resin dental composite

Open Chemistry ◽

10.1515/chem-2018-0090 ◽

2018 ◽

Vol 16 (1) ◽

pp. 905-911 ◽

Cited By ~ 1

Author(s):

Kinga Bociong ◽

Agata Szczesio ◽

Michal Krasowski ◽

Jerzy Sokolowski

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Flexural Strength ◽

Dental Composite ◽

Neat Resin ◽

Light Curing ◽

Contraction Stress ◽

Silanized Silica ◽

Composite Hardness ◽

Diametral Tensile Strength

AbstractAim of the study was to evaluate the influence of filler amounts on mechanical properties and contraction stress of light-curing experimental composite. Hardness, flexural strength, diametral tensile strength of material filled with 40, 50 or 60 wt. % of silanized silica were tested. The contraction stress was measured after 24 h by means of photoelastic study. The addition of 40-60 wt. % filler to composite caused significant increase in hardness, Young’s modulus and flexural strength. The DTS, after incorporating filler into polymer matrix, was valued at ~26 MPa. The composite containing 40 wt. % of filler demonstrated significantly lower contraction stress in comparison to neat resin and filled > 50 wt. % of silica.

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COMPARATIVE EVALUATION OF EFFECT OF TWO LIGHT CURING UNITS ON MECHANICAL PROPERTIES OF FILTEK BULK FILL COMPOSITE

International Journal of Advanced Research ◽

10.21474/ijar01/12424 ◽

2021 ◽

Vol 9 (02) ◽

pp. 104-110

Author(s):

Akshay Punjabi ◽

◽

Rahul Rao ◽

Ashish K. Jain ◽

Meenakshi Verma ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Compressive Strength ◽

Testing Machine ◽

Dental Composite ◽

Light Curing ◽

Circular Rings ◽

The Difference ◽

Diametral Tensile Strength

Context:The quality of light curing units can profoundly influence mechanical properties of dental composite materials. Aim: To compare effect of Woodpecker RTA Mini-S and Elipar Deep Cure-L curing units onmechanical properties (compressive strength, diametral tensile strength and microhardness) of Filtek Bulk-Fill. Methods and Materials: A total of 32 samples of Filtek Bulk Fill composite were divided into 2 equal groups (n=16). 12 samples in each group were fabricated using a tooth shaped mold and 4 in circular rings to test compressive strength, microhardness and diametral tensile strength, respectively. Theblocks were evaluated for the above parameters using Universal Testing Machine and Vickers Microhardness Tester.Independent sample-t test was used in this study (p< 0.05). Results: The results of this study showed that the group of composites cured using Elipar Deep Cure-L curing unit showed better mechanical properties and the difference between the groups was statistically significant for compressive strength and diametral tensile strength (p < 0.05) Conclusion: It was concluded that a curing unit of higher intensity and quality of output used in conjugation with bulk fill composites are likely to give better results.

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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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Effect of Preheating and Fatiguing on Mechanical Properties of Bulk-fill and Conventional Composite Resin

Operative Dentistry ◽

10.2341/19-092-l ◽

2019 ◽

Vol 45 (4) ◽

pp. 387-395

Author(s):

AA Abdulmajeed ◽

TE Donovan ◽

R Cook ◽

TA Sulaiman

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Tensile Strength ◽

Elastic Modulus ◽

Flexural Strength ◽

Composite Resin ◽

Statistical Significance ◽

Composite Resins ◽

Significant Difference ◽

Diametral Tensile Strength

Clinical Relevance Bulk-fill composite resins may have comparable mechanical properties to conventional composite resin. Preheating does not reduce the mechanical properties of composite resins. SUMMARY Statement of Problem: Bulk-fill composite resins are increasingly used for direct restorations. Preheating high-viscosity versions of these composites has been advocated to increase flowability and adaptability. It is not known what changes preheating may cause on the mechanical properties of these composite resins. Moreover, the mechanical properties of these composites after mastication simulation is lacking. Purpose: The purpose of this study was to evaluate the effect of fatiguing and preheating on the mechanical properties of bulk-fill composite resin in comparison to its conventional counterpart. Methods and Materials: One hundred eighty specimens of Filtek One Bulk Fill Restorative (FOBR; Bulk-Fill, 3M ESPE) and Filtek Supreme Ultra (FSU; Conventional, 3M ESPE) were prepared for each of the following tests: fracture toughness (International Organization for Standardization, ISO 6872), diametral tensile strength (No. 27 of ANSI/ADA), flexural strength, and elastic modulus (ISO Standard 4049). Specimens in the preheated group were heated to 68°C for 10 minutes and in the fatiguing group were cyclically loaded and thermocycled for 600,000 cycles and then tested. Two-/one-way analysis of variance followed by Tukey Honest Significant Difference (HSD) post hoc test was used to analyze data for statistical significance (α=0.05). Results: Preheating and fatiguing had a significant effect on the properties of both FSU and FOBR. Fracture toughness increased for FOBR specimens when preheated and decreased when fatigued (p=0.016). FOBR had higher fracture toughness value than FSU. Diametral tensile strength decreased significantly after fatiguing for FSU (p=0.0001). FOBR had a lower diametral tensile strength baseline value compared with FSU (p=0.004). Fatiguing significantly reduced the flexural strength of both FSU and FOBR (p=0.011). Preheating had no effect on the flexural strength of either FSU or FOBR. Preheating and fatiguing significantly decreased the elastic modulus of both composite resins equally (p>0.05). Conclusions: Preheating and fatiguing influenced the mechanical properties of composite resins. Both composites displayed similar mechanical properties. Preheating did not yield a major negative effect on their mechanical properties; the clinical implications are yet to be determined.

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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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Contamination of Composite Resin by Glove Powder and Saliva Contaminants: Impact on Mechanical Properties and Incremental Layer Debonding

Operative Dentistry ◽

10.2341/13-105-l ◽

2015 ◽

Vol 40 (4) ◽

pp. 396-402 ◽

Cited By ~ 3

Author(s):

NM Martins ◽

GU Schmitt ◽

HL Oliveira ◽

MM Madruga ◽

RR Moraes ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Flexural Strength ◽

Bond Strength ◽

Mechanical Performance ◽

Composite Resin ◽

Flexural Modulus ◽

Control Group ◽

Digital Manipulation ◽

Diametral Tensile Strength

SUMMARY This study investigated the influence of digital manipulation of a composite resin (Z250; 3M ESPE, St Paul, MN, USA) with gloves contaminated with powder and/or human stimulated saliva on the mechanical properties and incremental layer debonding of the restorative. The six groups tested were powdered gloves with or without saliva, powder-free gloves with or without saliva, powdered gloves with saliva cleaned with 70% ethanol, and no digital manipulation or contamination (control). Diametral tensile strength, flexural strength, flexural modulus, and incremental layer shear bond strength were evaluated. Each composite increment was digitally manipulated for 10 seconds. Data from each test were separately analyzed using analysis of variance and the Student-Newman-Keuls test (α=0.05). No significant differences for diametral tensile strength were observed. Manipulation of the composite using powder-free gloves with saliva or using gloves cleaned with ethanol generated higher flexural strength and modulus compared to the other groups. The control group and the group manipulated using powdered gloves with saliva generally showed lower mechanical performances. Lower incremental layer bond strength was observed for the group manipulated with powdered gloves without saliva. The control group and the groups manipulated with powdered gloves with saliva or cleaned with ethanol showed higher shear bond strengths. Most of the failures were cohesive. In conclusion, digital manipulation might be important for the composite resin to achieve better mechanical performance and incremental layer bond strength, provided that the gloves are not contaminated. Cleaning the gloves with ethanol might avoid the negative effects of digital manipulation using contaminated gloves.

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Comparative Effect of Self- or Dual-Curing on Polymerization Kinetics and Mechanical Properties in a Novel, Dental-Resin-Based Composite with Alkaline Filler

Materials ◽

10.3390/ma11010108 ◽

2018 ◽

Vol 11 (1) ◽

pp. 108 ◽

Cited By ~ 12

Author(s):

Nicoleta Ilie

Keyword(s):

Mechanical Properties ◽

Flexural Strength ◽

Mechanical Stability ◽

Polymerization Kinetics ◽

Dental Resin ◽

Polymerization Kinetic ◽

Double Bond Conversion ◽

Light Curing ◽

Dual Curing ◽

The Impact

Dental bulk-fill restorations with resin-composites (RBC) are increasing in popularity, but doubts concerning insufficient curing in depth still disconcert clinicians. An alternative might be offered by modern dual-cured RBCs, which additionally provide bioactive properties. This study assessed the impact of additional light-curing on polymerization kinetics, the degree of conversion (DC) and mechanical properties of a novel, dual-cured RBC with alkaline fillers. Since the bioactivity of a material often implies a release of compounds, the mechanical stability in simulated clinical environments was also evaluated. Polymerization kinetics and DC were assessed at 2- and 4-mm specimen depths in real-time up to one hour (n = 6). Incident and transmitted irradiance and radiant exposure were recorded at 2- and 4-mm depths. Micro-mechanical profiles (n = 6) were assessed in 100-µm steps along 6-mm deep specimens at 24 h post-polymerization. Flexural strength and modulus (n = 10) were determined up to three months of immersion in neutral (6.8) and acidic (4) pH conditions. DC variation in time was best described by a sigmoidal function (R2 > 0.98), revealing a retarded (3.4 ± 0.4 min) initiation in C=C double bond conversion in self-cured versus dual-cured specimens. The setting reaction kinetic was identical at 2- and 4-mm depths for the self-cure mode. For the dual-cure mode, polymerization initiated at 2-mm depth instantly with light-irradiation, while being retarded (0.8 min) at 4-mm depth. The material behaves similarly, irrespective of curing mode or depth, later than 11 min after mixing. Flexural strength and modulus was comparable to regular RBCs and maintained up to three months in both neutral and acidic conditions. Additional light-curing initially accelerates the polymerization kinetic and might help shorten the restauration procedure by hardening the material on demand, however with no effect on the final properties.

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Mechanical Property Improvement of Poly(Butylene Succinate) by Reinforcing with Modified Fumed Silica

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1025-1026.215 ◽

2014 ◽

Vol 1025-1026 ◽

pp. 215-220 ◽

Cited By ~ 1

Author(s):

Sasirada Weerasunthorn ◽

Pranut Potiyaraj

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Impact Strength ◽

Flexural Strength ◽

Fumed Silica ◽

Tensile Modulus ◽

Silica Particles ◽

Melt Mixing ◽

Butylene Succinate ◽

Ir Spectrophotometry

Fumed silica particles (SiO2) were directly added into poly (butylene succinate) (PBS) by melt mixing process. The effects of amount of fumed silica particles on mechanical properties of PBS/fumed silica composites, those are tensile strength, tensile modulus, impact strength as well as flexural strength, were investigated. It was found that the mechanical properties decreased with increasing fumed silica loading (0-3 wt%). In order to increase polymer-filler interaction, fumed silica was treated with 3-glycidyloxypropyl trimethoxysilane (GPMS), and its structure was analyzed by FT-IR spectrophotometry. The PBS/modified was found to possess better tensile strength, tensile modulus, impact strength and flexural strength that those of PBS/fumed silica composites.

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Performance Evaluation of Cellulose Nanofiber with Residual Hemicellulose as a Nanofiller in Polypropylene-Based Nanocomposite

Polymers ◽

10.3390/polym13071064 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1064

Author(s):

Mohd Nor Faiz Norrrahim ◽

Hidayah Ariffin ◽

Tengku Arisyah Tengku Yasim-Anuar ◽

Mohd Ali Hassan ◽

Nor Azowa Ibrahim ◽

...

Keyword(s):

Mechanical Properties ◽

Thermal Stability ◽

Weight Loss ◽

Tensile Strength ◽

Performance Evaluation ◽

Flexural Strength ◽

Decomposition Temperature ◽

Cellulose Nanofiber ◽

Hemicellulose Removal ◽

Reinforcement Material

Residual hemicellulose could enhance cellulose nanofiber (CNF) processing as it impedes the agglomeration of the nanocellulose fibrils and contributes to complete nanofibrillation within a shorter period of time. Its effect on CNF performance as a reinforcement material is unclear, and hence this study seeks to evaluate the performance of CNF in the presence of amorphous hemicellulose as a reinforcement material in a polypropylene (PP) nanocomposite. Two types of CNF were prepared: SHS-CNF, which contained about 11% hemicellulose, and KOH-CNF, with complete hemicellulose removal. Mechanical properties of the PP/SHS-CNF and PP/KOH-CNF showed an almost similar increment in tensile strength (31% and 32%) and flexural strength (28% and 29%) when 3 wt.% of CNF was incorporated in PP, indicating that hemicellulose in SHS-CNF did not affect the mechanical properties of the PP nanocomposite. The crystallinity of both PP/SHS-CNF and PP/KOH-CNF nanocomposites showed an almost similar value at 55–56%. A slight decrement in thermal stability was seen, whereby the decomposition temperature at 10% weight loss (Td10%) of PP/SHS-CNF was 6 °C lower at 381 °C compared to 387 °C for PP/KOH-CNF, which can be explained by the degradation of thermally unstable hemicellulose. The results from this study showed that the presence of some portion of hemicellulose in CNF did not affect the CNF properties, suggesting that complete hemicellulose removal may not be necessary for the preparation of CNF to be used as a reinforcement material in nanocomposites. This will lead to less harsh pretreatment for CNF preparation and, hence, a more sustainable nanocomposite can be produced.

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