scholarly journals Effect of Surface Polishing on Nano-Hardness and Elastic Modulus of Different Resin Composites after Immersion in Alcoholic Medium

2021 ◽  
Vol 5 (12) ◽  
pp. 327
Author(s):  
Dhaifallah Alqarni ◽  
Ali Alghamdi ◽  
Amr Saad ◽  
Abdullah Ali H. Alzahrani ◽  
Keiichi Hosaka
Keyword(s):  
Elastic Modulus ◽  
Resin Composite ◽  
Surface Hardness ◽  
Nanoindentation Test ◽  
Future Research ◽  
Artificial Ageing ◽  
Resin Composites ◽  
Alcoholic Medium ◽  
Surface Polishing ◽  
Effect Of Surface

There has been a great tendency toward using resin composite in dentistry and exploring nano-hardness, elastic modulus, and effect of polishing on its mechanical properties after its artificial ageing. This study aimed to evaluate the effect of surface polishing of four different resin composites on their nano-hardness and elastic modulus. This effect was tested right after light curing of composite resin and after its artificial ageing (immersion in alcoholic medium). Nanoindentation test preparations, surface roughness, surface hardness, and scanning electron microscope were conducted across the four different resin composites: Clearfil AP-X (APX), Estelite Sigma Quick (ESQ), Beautifil II (BE2), and FiltekTM Supreme Ultra Universal restorative (FSU). We found that difference in fillers load and particle size are amongst the factors influencing hardness and modulus of elasticity. The APX is the highest in term of hardness due to fillers load and size while the ESQ is the lowest because all fillers in nano size and distributed homogenously. The significance of surface polishing of the studied resin composite restorations was highlighted. Future research may focus on exploring survival rate of polished and non-polished composite surfaces with emphasis on measuring degree of conversion and impacts of polished and non-polished surfaces on the individuals’ oral health quality of life.

The Effect of Surface Self-Nanocrystallization on Low-Temperature Gas Carburization for AISI 316L Steel

2019 ◽  
Vol 795 ◽  
pp. 137-144
Author(s):  
Zhe Liu ◽  
Ya Wei Peng ◽  
Jian Ming Gong ◽  
Chao Ming Chen
Keyword(s):  
Stainless Steel ◽  
Elastic Modulus ◽  
Austenitic Stainless Steel ◽  
Low Temperature ◽  
Surface Hardness ◽  
Electron Probe Micro Analyzer ◽  
Gas Carburizing ◽  
316L Steel ◽  
Negative Effect ◽  
Effect Of Surface

In this work, the effect of surface self-nanocrystallization on low-temperature gas carburizing for AISI316L austenitic stainless steel has been studied. The surface ultrasonic rolling processing (SURP) was used to prepare nanostructured surface layers, and then the un-SURP and SURP samples were treated by LTGC at 470 °C for 10 h, 20 h and 30 h. In order to analyze the effect of surface self-nanocrystallization on low-temperature gas carburizing, optical microscopy (OM), atomic force microscope (AFM), scanning electron probe micro-analyzer (EPMA) and nano-indentation analyzer were used. The results show depth of SURP-induced plastic deformation layer was about 330 μm. Meanwhile, the surface hardness and elastic modulus were increased but the surface roughness decreased obviously after SURP. After low-temperature gas carburizing, according to the results of the thickness, carbon concentration, nano-hardness and elastic modulus of the carburized layer, the conclusion is that surface self-nanocrystallization carried by SURP has a negative effect on the low-temperature gas carburizing for AISI316L austenitic stainless steel and with the increase of carburizing time, the greater the adverse effect on carburizing.

scholarly journals Microleakage at enamel and dentin margins with a bulk fills flowable resin

2014 ◽  
Vol 08 (01) ◽  
pp. 001-008 ◽  
Author(s):  
Nicola Scotti ◽  
Allegra Comba ◽  
Alberto Gambino ◽  
Davide Salvatore Paolino ◽  
Mario Alovisi ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Resin Composite ◽  
In Vitro Study ◽  
Artificial Ageing ◽  
Resin Composites ◽  
Class V ◽  
Dye Penetration ◽  
Before And After ◽  
Blue Solution

ABSTRACT Objective: The aim of this in vitro study was to evaluate the marginal sealing ability of a bulk fill flowable resin composite on both enamel and dentin substrates. Materials and Methods: 48 non-carious molars were selected and four Class-V cavities were prepared at the CEJ of each sample. Cavities were filled with Venus Diamond (Heraeus Kulzer); Venus Diamond Flow (Heraeus Kulzer) and Surefil SDR (Dentsply). Samples were divided into two groups: First group samples were immersed in a methylene blue solution for 30 min at 25°C. Second group samples were artificially aged and then treated with methylene blue. Samples were sectioned in the center of the restoration and observed with a 40x stereomicroscope, and the percentage of cavity infiltration was calculated. Results: Results were analyzed statistically by ANOVA (P < 0.05). The amount of infiltration was significantly lower for the enamel substrate compared with dentin (P = 0.0001) and in samples immediately immersed in methylene blue compared with those that were artificially aged (P = 0.011). The interaction between the composite material and the marginal substrate significantly affected dye penetration (P = 0.006). Conclusions: Bulk fill flowable resins provided significantly better marginal seal in dentin, both before and after artificial ageing. Nanohybrid resin composites and bulk fill flowable resins showed similar microleakage values at enamel margins. Bulk fills flowable resins provided significantly better marginal seal in dentin, both before and after artificial ageing. Nanohybrid resin composites and bulk fill flowable resins showed similar microleakage values at enamel margins.

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

2010 ◽  
Vol 25 (3) ◽  
pp. 529-536 ◽  
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.

Marginal Gap Formation in Approximal “Bulk Fill” Resin Composite Restorations After Artificial Ageing

2018 ◽  
Vol 43 (2) ◽  
pp. 180-189 ◽  
Author(s):  
A Peutzfeldt ◽  
S Mühlebach ◽  
A Lussi ◽  
S Flury
Keyword(s):  
Tap Water ◽  
Resin Composite ◽  
Class Ii ◽  
Artificial Ageing ◽  
Resin Composites ◽  
Gap Formation ◽  
Marginal Gap ◽  
Significance Level ◽  
Significant Difference

SUMMARY The aim of this in vitro study was to investigate the marginal gap formation of a packable “regular” resin composite (Filtek Supreme XTE [3M ESPE]) and two flowable “bulk fill” resin composites (Filtek Bulk Fill [3M ESPE] and SDR [DENTSPLY DeTrey]) along the approximal margins of Class II restorations. In each of 39 extracted human molars (n=13 per resin composite), mesial and distal Class II cavities were prepared, placing the gingival margins below the cemento-enamel junction. The cavities were restored with the adhesive system OptiBond FL (Kerr) and one of the three resin composites. After restoration, each molar was cut in half in the oro-vestibular direction between the two restorations, resulting in two specimens per molar. Polyvinylsiloxane impressions were taken and “baseline” replicas were produced. The specimens were then divided into two groups: At the beginning of each month over the course of six months' tap water storage (37°C), one specimen per molar was subjected to mechanical toothbrushing, whereas the other was subjected to thermocycling. After artificial ageing, “final” replicas were produced. Baseline and final replicas were examined under the scanning electron microscope (SEM), and the SEM micrographs were used to determine the percentage of marginal gap formation in enamel or dentin. Paramarginal gaps were registered. The percentages of marginal gap formation were statistically analyzed with a nonparametric analysis of variance followed by Wilcoxon-Mann-Whitney tests and Wilcoxon signed rank tests, and all p-values were corrected with the Bonferroni-Holm adjustment for multiple testing (significance level: α=0.05). Paramarginal gaps were analyzed descriptively. In enamel, significantly lower marginal gap formation was found for Filtek Supreme XTE compared to Filtek Bulk Fill (p=0.0052) and SDR (p=0.0289), with no significant difference between Filtek Bulk Fill and SDR (p=0.4072). In dentin, significantly lower marginal gap formation was found for SDR compared to Filtek Supreme XTE (p&lt;0.0001) and Filtek Bulk Fill (p=0.0015), with no significant difference between Filtek Supreme XTE and Filtek Bulk Fill (p=0.4919). Marginal gap formation in dentin was significantly lower than in enamel (p&lt;0.0001). The percentage of restorations with paramarginal gaps varied between 0% and 85%, and for all three resin composites the percentages were markedly higher after artificial ageing. The results from this study suggest that in terms of marginal gap formation in enamel, packable resin composites may be superior to flowable “bulk fill” resin composites, while in dentin some flowable “bulk fill” resin composites may be superior to packable ones.

scholarly journals The Nanomechanical and Tribological Properties of Restorative Dental Composites after Exposure in Different Types of Media

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Hong-Yi Fan ◽  
Xue-Qi Gan ◽  
Yang Liu ◽  
Zhuo-Li Zhu ◽  
Hai-Yang Yu
Keyword(s):  
Elastic Modulus ◽  
Scanning Probe Microscopy ◽  
Wear Behavior ◽  
Dental Composites ◽  
Nanoindentation Test ◽  
Wear Depth ◽  
Resin Composites ◽  
Acidic Solutions ◽  
Commercial Resin ◽  
Different Types

The aim of this study was to evaluate the effects of various acidic solutions on the surface mechanical properties of commercial resin composites with different microstructures (Filtek Z350 XT, TPH3, Durafill, and Superlux). Specimens were immersed in orange juice, cola, and distilled water for 5 days and the nanohardness, elastic modulus, and wear behavior of the samples were determined via the nanoindentation test and a reciprocating nanoscratch test. The nanoscratch morphology was observed using scanning electron microscopy (SEM) and the wear depth was recorded by scanning probe microscopy (SPM). The results indicate that the nanofilled resin composites had the greatest hardest and highest elastic modulus, whereas the microfilled composites exhibited the lowest nanohardness and elastic modulus values. SEM observations showed that all resin composites underwent erosion and surface degradation after immersion in acidic solutions. Furthermore, the wear resistance was influenced by the composition of the acidic solution and was correlated with the nanohardness and elastic modulus. The dominant wear mechanism changed from plastic deformation to delamination after immersion in acidic solutions.

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

2017 ◽  
Vol 42 (6) ◽  
pp. E177-E187 ◽  
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.

scholarly journals Influences of Successive Exposure to Bleaching and Fluoride Preparations on the Surface Hardness and Roughness of the Aged Resin Composite Restoratives

Medicina ◽  
2020 ◽  
Vol 56 (9) ◽  
pp. 476
Author(s):  
Khalid M. Abdelaziz ◽  
Shugufta Mir ◽  
Shafait Ullah Khateeb ◽  
Suheel M. Baba ◽  
Saud S. Alshahrani ◽  
...  
Keyword(s):  
Resin Composite ◽  
Surface Hardness ◽  
Resin Composites ◽  
Vickers Hardness Number ◽  
Fluoride Treatment ◽  
Intermittent Exposure ◽  
Oral Environment ◽  
Topical Fluoride ◽  
Aged Composite

Background and Objectives: Surfaces of composite restorations are adversely affected upon bleaching and topical fluoride application. Such a procedure is normally carried out in the presence of restorations already serving in a different oral environment, although previous in vitro studies only considered the freshly-prepared composite specimens for assessment. The current study accordingly aimed to evaluate both the surface hardness and roughness of aged composite restoratives following their successive exposure to bleaching and topical fluoride preparations. Materials and Methods: Disc specimens were prepared from micro-hybrid, nano-filled, flowable and bulk-fill resin composites (groups 1–4, n = 60 each). All specimens were subjected to artificial aging before their intermittent exposure to surface treatment with: none (control), bleach or topical fluoride (subgroups 1–3, n = 20). All surface treatments were interrupted with two periods of 5000 thermal cycles. Specimens’ surfaces were then tested for both surface hardness (Vickers hardness number (VHN), n = 10) and roughness (Ra, n = 10). The collected VHNs and Ras were statistically analyzed using two-way ANOVA and Tukey’s comparisons at α = 0.05 to confirm the significance of differences between subgroups. Results: None of the tested composites showed differences in surface hardness and roughness between the bleached and the non-treated specimens (p > 0.05), but the bleached flowable composite specimens only were rougher than their control (p < 0.000126). In comparison to the control, fluoride treatment not only reduced the surface hardness of both micro-hybrid (p = 0.000129) and flowable (p = 0.0029) composites, but also increased the surface roughness of all tested composites (p < 0.05). Conclusion: Aged composite restoratives provide minimal surface alterations on successive bleaching and fluoride applications. Flowable resin composite is the most affected by such procedures. Although bleaching seems safe for other types of composites, the successive fluoride application could deteriorate the aged surfaces of the tested resin composites.

scholarly journals Effect of surface conditioning methods, adhesive systems and resin composite on repair strength of dimethacrylate and silorane resin composites

2016 ◽  
Vol 30 (24) ◽  
pp. 2736-2744 ◽  
Author(s):  
Adriano Fonseca Lima ◽  
Thatiana de Vicente Leite ◽  
Alan Muniz Palialol ◽  
Anderson Catelan ◽  
Flávio Henrique Baggio Aguiar ◽  
...  
Keyword(s):  
Resin Composite ◽  
Resin Composites ◽  
Adhesive Systems ◽  
Surface Conditioning ◽  
Effect Of Surface

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

2019 ◽  
Vol 30 (3) ◽  
pp. 279-284
Author(s):  
Guillermo Grazioli ◽  
Alejandro Francia ◽  
Carlos Enrique Cuevas-Suárez ◽  
Cesar Henrique Zanchi ◽  
Rafael Ratto De Moraes
Keyword(s):  
Elastic Modulus ◽  
Flexural Strength ◽  
Mechanical Performance ◽  
Resin Composite ◽  
Low Cost ◽  
Negative Control ◽  
Control Group ◽  
Thermal Treatments ◽  
Resin Composites ◽  
Thermal Methods

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.

scholarly journals Differences level of hybrid resin composite’s hardness based on post-irradiation time with photoactivated light emitting diode

2012 ◽  
Vol 24 (2) ◽  
Author(s):  
Esther Bianca ◽  
Milly Armilia Andang ◽  
Endang Sukartini
Keyword(s):  
Irradiation Time ◽  
Light Emitting Diode ◽  
Resin Composite ◽  
Surface Hardness ◽  
Resin Composites ◽  
Light Emitting ◽  
Hybrid Resin ◽  
Post Irradiation ◽  
Significant Difference ◽  
Curing Light

Introduction: Adequate surface hardness of the resin composites is important to obtain optimum clinical performance of the restoratives in stress dental bearing areas. For light-activated resin composites, polymerization begins when curing light initiates polymerization and continues after the curing light goes off. The degree of conversion and hardness of resin composite is also affected by post-irradiation time. The objective of this study was to evaluate the difference of the hardness hybrid resin composite based on post-irradiation time at 10 minutes, 24 hours, and 7 days with photoactivated light-emitting diode (LED) to obtain the optimum hardness. Methods: This study was using a true experimental research method. Thirty samples of hybrid resin composites, disk-shaped of 6 mm in diameter and 2 mm in depth were polymerized by LED LCU at 800mW/cm2 for 20 seconds. The hardness of the resin composite was measured by Vickers Hardness Tester. The result was analyzed statistically with ANOVA. Results: There was a significant difference level of hardness among the three groups. Hardness mean value for post-irradiation time at 10 minutes was 56,4 VHN, for post-irradiation time at 24 hours was 65,8 VHN, and for post-irradiation time at 7 days was 60,0 VHN. Conclusion: There were differences level of hybrid resin composite’s hardness based on the post-irradiation time at 10 minutes, 24 hours, and 7 days with photoactivated LED and the optimum hardness of post-irradiation time at 24 hours.

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