scholarly journals Evaluation of the Degree of Conversion, Residual Monomers and Mechanical Properties of Some Light-Cured Dental Resin Composites

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2109 ◽  
Author(s):  
Marioara Moldovan ◽  
Robert Balazsi ◽  
Andrada Soanca ◽  
Alexandra Roman ◽  
Codruta Sarosi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Properties ◽  
Degree Of Conversion ◽  
Resin Composites ◽  
Mechanical Parameters ◽  
Dental Resin ◽  
Posterior Teeth ◽  
Commercial Resin ◽  
Diametral Tensile Strength

The novelty of this study consists in the formulation and characterization of three experimental dental composites (PM, P14M, P2S) for cervical dental lesion restoration compared to the commercial composites Enamel plus HRi® - En (Micerium S.p.A, Avengo, Ge, Italy), G-ænial Anterior® - Ge, (GC Europe N.V., Leuven, Belgium), Charisma® - Ch (Heraeus Kulzer, Berkshire, UK). The physio-chemical properties were studied, like the degree of conversion and the residual monomers in cured samples using FTIR-ATR (attenuated total reflectance) and HPLC-UV (ultraviolet detection), as well as the evaluation of the mechanical properties of the materials. The null hypothesis was that there would be no differences between experimental and commercial resin composites regarding the evaluated parameters. Statistical analysis revealed that water and saliva storage induced significant modifications of all mechanical parameters after three months for all tested materials, except for a few comparisons for each type of material. Storage medium seemed not to alter the values of mechanical parameters in comparison with the initial ones for: diametral tensile strength (DTS-saliva for Ge and PM, compressive strength (CS)-water for Ch, DTS-water and Young’s modulus YM-saliva for P14M and YM-water/ saliva for P2S (p > 0.05). Two of the experimental materials showed less than 1% residual monomers, which sustains good polymerization efficiency. Experimental resin composites have good mechanical properties, which makes them recommendable for the successful use in load-bearing surfaces of posterior teeth.

scholarly journals Development of Chlorhexidine Loaded Halloysite Nanotube Based Experimental Resin Composite with Enhanced Physico-Mechanical and Biological Properties for Dental Applications

2020 ◽  
Vol 4 (2) ◽  
pp. 81 ◽  
Author(s):  
Tejas Barot ◽  
Deepak Rawtani ◽  
Pratik Kulkarni
Keyword(s):  
Mechanical Properties ◽  
Resin Composite ◽  
Biological Properties ◽  
Degree Of Conversion ◽  
Dental Composites ◽  
Resin Composites ◽  
Dental Resin ◽  
Dental Resin Composites ◽  
Mass Fractions ◽  
Nih 3T3

Objective: The objective of this study was to explore the effect of Chlorhexidine-loaded Halloysite nanotubes (HNT/CHX) fillers (diverse mass fractions from 1 to 10 wt.%) on physicochemical, morphological and biological properties of newly developed experimental dental resin composite, in order to compare with the properties of composites composed of conventional glass fillers. Methods: The dental resin composites were prepared by incorporating various proportions of HNT/CHX. Six different groups of specimens: control group and five groups composed of varied mass fractions of HNT/CHX (e.g., 1.0, 2.5, 5.0, 7.5 and 10 wt.%) as fillers in each group were fabricated. Mechanical properties of the composites were monitored, using UTM. The degree of conversion of dental resin composites and their depth of cure were also evaluated. Antimicrobial properties of dental composites were studied in vitro by applying agar diffusion test on strain Streptococcus mutans and cytotoxicity were studied using NIH-3T3 cell line. Results: The incorporation of varied mass fractions (1.0 to 5.0 wt.%) of HNT/CHX in dental resins composites enhanced mechanical properties considerably with significant antibacterial activity. The slight decrease in curing depth and degree of conversion values of composites indicates its durability. No cytotoxicity was noticed on NIH-3T3 cell lines. Significance: Consistent distribution of HNT/CHX as a filler into dental composites could substantially improve not only mechanical properties but also biological properties of dental composites.

scholarly journals Effect of Accelerated Aging on Some Mechanical Properties and Wear of Different Commercial Dental Resin Composites

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2769
Author(s):  
Jonne Oja ◽  
Lippo Lassila ◽  
Pekka K. Vallittu ◽  
Sufyan Garoushi
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Accelerated Aging ◽  
Wear Depth ◽  
Resin Composites ◽  
Expiration Date ◽  
Dental Resin ◽  
Hydrothermal Aging ◽  
Dental Resin Composites

The aim of current in vitro research was to determine the effect of hydrothermal accelerated aging on the mechanical properties and wear of different commercial dental resin composites (RCs). In addition, the effect of expiration date of the composite prior its use was also evaluated. Five commercially available RCs were studied: Conventional RCs (Filtek Supreme XTE, G-aenial Posterior, Denfil, and >3y expired Supreme XTE), bulk-fill RC (Filtek Bulk Fill), and short fiber-reinforced RC (everX Posterior). Three-point flexural test was used for determination of ultimate flexural strength (n = 8). A vickers indenter was used for testing surface microhardness. A wear test was conducted with 15,000 chewing cycles using a dual-axis chewing simulator. Wear pattern was analyzed by a three-dimensional (3D) noncontact optical profilometer. Degree of C=C bond conversion of monomers was determined by FTIR-spectrometry. The specimens were either dry stored for 48 h (37 °C) or boiled (100 °C) for 16 h before testing. Scanning electron microscopy (SEM) was used to evaluate the microstructure of each material. Data were analyzed using ANOVA (p = 0.05). Hydrothermal aging had no significant effects on the surface wear and microhardness of tested RCs (p > 0.05). While flexural strength significantly decreased after aging (p < 0.05), except for G-aenial Posterior, which showed no differences. The lowest average wear depth was found for Filtek Bulk Fill (29 µm) (p < 0.05), while everX Posterior and Denfil showed the highest wear depth values (40, 39 µm) in both conditions. Passing the expiration date for 40 months did not affect the flexural strength and wear of tested RC. SEM demonstrated a significant number of small pits on Denfil’s surface after aging. It was concluded that the effect of accelerated aging may have caused certain weakening of the RC of some brands, whereas no effect was found with one brand of RC. Thus, the accelerated aging appeared to be more dependent on material and tested material property.

Evaluating antibacterial and surface mechanical properties of chitosan modified dental resin composites

2020 ◽  
Vol 28 (2) ◽  
pp. 165-173 ◽  
Author(s):  
Shahid Ali ◽  
Laila Sangi ◽  
Naresh Kumar ◽  
Bharat Kumar ◽  
Zohaib Khurshid ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Resin Composites ◽  
Dental Resin ◽  
Dental Resin Composites

Characterization of Nano- and Micro-Filled Resin Composites Used as Dental Restorative Materials

2008 ◽  
Author(s):  
Dalia Abdel Hamid ◽  
Amal Esawi ◽  
Inas Sami ◽  
Randa Elsalawy
Keyword(s):  
Resin Composite ◽  
Physical And Mechanical Properties ◽  
Sem Analysis ◽  
Indentation Modulus ◽  
Resin Composites ◽  
Adhesively Bonded ◽  
Dental Resin ◽  
Tooth Structure ◽  
Dental Restorative

Adhesively-bonded resin composites have the advantage of conserving sound tooth structure with the potential for tooth reinforcement, while at the same time providing an aesthetically acceptable restoration. However, no composite material has been able to meet both the functional needs of posterior restorations and the superior aesthetics required for anterior restoration. In an attempt to develop a dental resin composite that had the mechanical strength of hybrid composite materials and the superior polish and gloss retention associated with microfilled materials, nanofilled resin composites have been introduced in the market. Although nanofillers are the most popular fillers utilized in current visible light-activated dental resin composites and are claimed to be the solution for the most challenging material limitations as a universal restorative material, the mechanisms by which these fillers influence the resin composite properties are not well explained. In this study, some physical and mechanical properties of a nanofilled resin composite containing 60 vol. % zirconia and silica fillers were evaluated and compared to those of a microhybrid resin composite of the same composition. The nanofilled resin composite was found to have equivalent polymerization shrinkage and depth of cure to the microhybrid material but a slightly lower degree of conversion and density. Regarding mechanical behaviour, although the nanocomposite was found to exhibit significantly higher wear resistance, and equivalent flexural strength, its indentation modulus and nanohardness were slightly lower. Field-emission scanning electron microscopy (FE-SEM) analysis was conducted in order to evaluate the microstructure and to obtain a better understanding of the effect of the nanofillers on the behaviour of the nanocomposite.

Ca-Doped mesoporous SiO2/dental resin composites with enhanced mechanical properties, bioactivity and antibacterial properties

2018 ◽  
Vol 6 (3) ◽  
pp. 477-486 ◽  
Author(s):  
Yu Zhang ◽  
Cui Huang ◽  
Jiang Chang
Keyword(s):  
Mechanical Properties ◽  
Antibacterial Activity ◽  
Antibacterial Properties ◽  
Resin Composites ◽  
Dental Resin ◽  
Dental Resin Composites ◽  
Mesoporous Sio2

MCS containing resin composites possess enhanced mechanical properties and antibacterial activity, and can smartly induce the deposition of apatite minerals.

Preparation and characterization of Mechanical Properties of Epoxy Resin Composites reinforced with Non Bio-degradable Wastes

2018 ◽  
Vol 5 (9) ◽  
pp. 19723-19727 ◽  
Author(s):  
Asmeeta Jagdev ◽  
Bidyut Prava Jena ◽  
Bijaya Bijeta Nayak ◽  
Suchismita Satapathy
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Resin Composites ◽  
Epoxy Resin Composites

scholarly journals Nano-mechanical Properties and Pore-Scale Characterization of Different Rank Coals

2019 ◽  
Vol 29 (3) ◽  
pp. 1787-1800 ◽  
Author(s):  
Yihuai Zhang ◽  
Maxim Lebedev ◽  
Gregory Smith ◽  
Yu Jing ◽  
Andreas Busch ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Vitrinite Reflectance ◽  
Chemical Properties ◽  
Coal Bed ◽  
Coal Bed Methane ◽  
Indentation Modulus ◽  
Micro Computed Tomography ◽  
Micro Structure ◽  
Nano Indentation

ABSTRACT Characterization of coal micro-structure and the associated rock mechanical properties are of key importance for coal seam exploration, coal bed methane development, enhanced coal bed methane production and CO2 storage in deep coal seams. Considerable knowledge exists about coal chemical properties, but less is known about the nanoscale to the micro-scale structure of coals and how they change with coal strength across coal ranks. Thus, in this study, 3D X-ray micro-computed tomography (with a voxel size of 3.43 µm) and nano-indentation tests were conducted on coal samples of different ranks from peat to anthracite. The micro-structure of peats showed a well-developed pore system with meso- and micro-pores. The meso-pores essentially disappear with increasing rank, whereas the micro-pores persist and then increase past the bituminous rank. The micro-fracture system develops past the peat stage and by sub-bituminous ranks and changes into larger and mature fracture systems at higher ranks. The nano-indentation modulus showed the increasing trend from low- to high-rank coal with a perfect linear relationship with vitrinite reflectance and is highly correlated with carbon content as expected.

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