scholarly journals Improved performance of Bis-GMA dental composites reinforced with surface-modified PAN nanofibers

Author(s):  
Parisa Amiri ◽  
Zahra Talebi ◽  
Dariush Semnani ◽  
Rouhollah Bagheri ◽  
Hossein Fashandi

AbstractIn the present work, polyacrylonitrile (PAN) nanofibers reinforced dental composites were investigated to achieve the improved interfacial adhesion between the PAN nanofiber and resin matrix using surface modification of nanofibers. PAN nanofibers mat were prepared by electrospinning and then, surface treated with the activated bisphenol A glycidyl methacrylate (Bis-GMA)/triethyleneglycol dimethacrylate (TEGDMA) (50/50 mass ratio) dental resin followed by photo-curing. Also, the treated nanofibers mat was milled into a powder to achieve the uniform distribution of nanofibers in the matrix resin. The reinforced dental composite were prepared by mixing the various mass fraction of the powder (0.5–15 wt%) with the Bis-GMA/TEGDMA dental monomers. The effect of weight ratio of surface-modified nanofibers to blend resin on the chemical structure, morphology, compression and flexural properties, color and polymerization shrinkage of dental composites was evaluated. The results showed that using surface-treated nanofibers with content of 5 wt% enhanced the compression strength, flexural strength, flexural modulus and work of rupture of the resultant dental composite by factors of 23%, 7%, 80%, and 145%, respectively, comparing to the unreinforced neat resin. Also, the polymerization shrinkage reduces by 37%. These significant improved properties of the dental composite could be due to the semi-interpenetration network formation between surface-modified nanofibers and resin matrix and well distribution of nanofibers in the dental resin. Further increasing the nanofiber content led to poor mechanical properties of obtained dental composites. The results also, revealed that the color of resin composite could be whiter using modified PAN nanofibers as the filler.

2019 ◽  
Vol 30 (3) ◽  
pp. 272-278 ◽  
Author(s):  
Jamille Favarão ◽  
Dayane Carvalho Ramos Salles de Oliveira ◽  
Mateus Garcia Rocha ◽  
Maurício Matté Zanini ◽  
Gabriel Flores Abuna ◽  
...  

Abstract The aim of this study was to use the isobornyl methacrylate (IBOMA) as a combining or substituent diluent monomer in the resin matrix of dental resin composites. Thus, the resin matrix was formulated with 60 wt% of BisGMA and 40 wt% of diluent monomers. TEGDMA as the only diluent monomer was used as control with 40 wt%, while total substitution of TEGDMA was done with 40 wt% of IBOMA. The combination of IBOMA and TEGDMA was done with 20 wt% of each monomer. To the resin matrix, 65 wt% of filler particles was added. Degree of conversion (DC) using FT-IR, flexural strength (FS), flexural modulus (FM), polymerization shrinkage by gap formation (GF), Knoop hardness (KH) and solvent degradation (SD) were evaluated. Data were analyzed using ANOVA and Tukey’s test (α=0.05; b=0.2). The results showed that reducing or substituting TEGDMA using IBOMA did not affect the DC (0.085), FS (p=0.886) or FM (p=0.414). Also, when IBOMA was used, lower GF was found in comparison to the control containing only TEGDMA as the diluent monomer (p=0.032). However, even though all composites presented reduction in KH during the SD test, the combination of IBOMA and TEGDMA showed similar reduction in KHN in comparison to the control group (p=0.001), while the total substitution of TEGDMA with IBOMA decreased KHN after SD (p=0.041). Thus, the combination of IBOMA and TEGDMA seem to reduce SD and GF without affecting the properties of resin composites.


2008 ◽  
Vol 87 (8) ◽  
pp. 710-719 ◽  
Author(s):  
J.L. Drummond

The intent of this article is to review the numerous factors that affect the mechanical properties of particle- or fiber-filler-containing indirect dental resin composite materials. The focus will be on the effects of degradation due to aging in different media, mainly water and water and ethanol, cyclic loading, and mixed-mode loading on flexure strength and fracture toughness. Several selected papers will be examined in detail with respect to mixed and cyclic loading, and 3D tomography with multi-axial compression specimens. The main cause of failure, for most dental resin composites, is the breakdown of the resin matrix and/or the interface between the filler and the resin matrix. In clinical studies, it appears that failure in the first 5 years is a restoration issue (technique or material selection); after that time period, failure most often results from secondary decay.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 470
Author(s):  
Andrea Kowalska ◽  
Jerzy Sokolowski ◽  
Kinga Bociong

The presented paper concerns current knowledge of commercial and alternative photoinitiator systems used in dentistry. It discusses alternative and commercial photoinitiators and focuses on mechanisms of polymerization process, in vitro measurement methods and factors influencing the degree of conversion and hardness of dental resins. PubMed, Academia.edu, Google Scholar, Elsevier, ResearchGate and Mendeley, analysis from 1985 to 2020 were searched electronically with appropriate keywords. Over 60 articles were chosen based on relevance to this review. Dental light-cured composites are the most common filling used in dentistry, but every photoinitiator system requires proper light-curing system with suitable spectrum of light. Alternation of photoinitiator might cause changing the values of biomechanical properties such as: degree of conversion, hardness, biocompatibility. This review contains comparison of biomechanical properties of dental composites including different photosensitizers among other: camphorquinone, phenanthrenequinone, benzophenone and 1-phenyl-1,2 propanedione, trimethylbenzoyl-diphenylphosphine oxide, benzoyl peroxide. The major aim of this article was to point out alternative photoinitiators which would compensate the disadvantages of camphorquinone such as: yellow staining or poor biocompatibility and also would have mechanical properties as satisfactory as camphorquinone. Research showed there is not an adequate photoinitiator which can be as sufficient as camphorquinone (CQ), but alternative photosensitizers like: benzoyl germanium or novel acylphosphine oxide photoinitiators used synergistically with CQ are able to improve aesthetic properties and degree of conversion of dental resin.


2010 ◽  
Vol 25 (3) ◽  
pp. 529-536 ◽  
Author(s):  
Yijun Wang ◽  
Isabel K. Lloyd

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.


2013 ◽  
Vol 795 ◽  
pp. 626-630 ◽  
Author(s):  
Saad Omar Alsharif ◽  
Md Akil Hazizan ◽  
Nasser Abbas Abd El-Aziz ◽  
Zainal Arifin Ahmad

The aim of this study is to investigate the effect of filler loading on the sorption and solubility of Simulated Body Fluid (SBF) of self-prepared micro dental resin composites. The prepared resin composite was based on silica (SiO2) particles and bisphenol-a-glycidyl methacrylate (Bis-GMA) as a base monomer and triethylene glycol dimethacrylate (TEGDMA) as a co-monomer. The filler was mixed with monomers, in proportions of 40, 50 and 60 wt.%. A resin matrix containing 0 wt.% filler was used as the control composition to evaluate the effect of filler loading on the sorption and solubility of SBF. The experimental methods were based on the procedure mentioned in the ISO 4049 (2009) standard for dentistry-Polymer-based restorative Materials. The sorption and solubility of resin matrix/SiO2composite decreased gradually as the filler loading increased. The increase of filler loading showed significant differences in the sorption and solubility as tested by ANOVA (P= 0.000).


2020 ◽  
Vol 4 (2) ◽  
pp. 81 ◽  
Author(s):  
Tejas Barot ◽  
Deepak Rawtani ◽  
Pratik Kulkarni

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.


Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 84
Author(s):  
Mostafa Seifan ◽  
Zahra Sarabadani ◽  
Aydin Berenjian

Dental restorative materials suffer from major drawbacks, namely fracture and shrinkage, which result in failure and require restoration and replacement. There are different methods to address these issues, such as increasing the filler load or changing the resin matrix of the composite. In the present work, we introduce a new viable process to heal the generated cracks with the aid of urease enzyme. In this system, urease breaks down the salivary urea which later binds with calcium to form calcium carbonate (CaCO3). The formation of insoluble CaCO3 fills any resultant fracture or shrinkage from the dental composure hardening step. The healing process and the formation of CaCO3 within dental composites were successfully confirmed by optical microscope, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDS) methods. This research demonstrates a new protocol to increase the service life of dental restoration composites in the near future.


2015 ◽  
Vol 815 ◽  
pp. 336-341
Author(s):  
Shuang Bao ◽  
Rui Li Wang ◽  
Bin Sun ◽  
Xiao Ze Jiang ◽  
Mei Fang Zhu

To explore the preparation of novel dental resin composites with enhanced properties, two commercial silica particles with sizes of around 1μm and 40 nm were chosen as inorganic fillers, and firstly surface functionalized by 3-methacryloxypropyltrimethoxysilane (γ-MPS) to incorporate cross-linkable vinyl groups onto the surface of fillers. Then the modified fillers were blended with organic monomers, bisphenolAdiglycidyldimethacrylate (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA), to fabricate the resin compositeswith a three-roll mixer.Resin composites with various weight percentage of fillers and component ratio of microparticle and nanoparticle were prepared. Surface functionalization of silica particles was characterized by fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), and mechanical properties degree of conversion, and depth of cure of the resultant resin composites were investigated byuniversal testing machineand FTIR. The results indicated that surface modification of silica particles was successful and the surface organic contents were 3.29% and 4.34%, respectively. Among the studied resin composites, the resin composite with 75 wt.% silica particles (59 wt.% microparticles and 16 wt.% nanoparticles) presented the highest value of depth of cure (5.52 ± 0.07 mm), and optimum mechanical properties such as flexural strength (149.8 ± 3.3 MPa), flexural modulus (13.8 ± 0.06 GPa), compressive strength (340.6 ± 8.3 MPa) and Vicker’smicrohardness (78.26 ± 2.45 HV). The study of dental resin composites fabricated from commercial silica particles with excellent properties might provide a new sight for realizing the preparation of this kind of dental resin composites in an industrial scale.


2018 ◽  
Vol 53 (23) ◽  
pp. 3217-3228 ◽  
Author(s):  
Abolfazl Mirjalili ◽  
Ali Zamanian ◽  
Seyed Mohammad Mahdi Hadavi

One of the most important aspects of dental resin composites is the ability to improve mechanical properties by adding reinforcing filler particles. TiO2 nanotubes are expected to improve the physical and mechanical properties of silica micro-filled dental composite. Therefore, TiO2 nanotubes were synthesized using an alkaline hydrothermal process and then functionalized with 3-methacryloxypropyl-trimethoxysilane. TiO2 nanotubes were characterized by scanning and transmission electron microscopies, X-ray diffraction and Fourier transform infrared spectroscopy. Different quantities of TiO2 nanotubes and silica microparticles were reinforced in bisphenol A-glycidyl methacrylate (Bis-GMA) and tri-ethylene glycol dimethacrylate to prepare dental composite samples. Thereafter, the flexural strength and modulus, compressive strength, degree of conversion of monomers, wear resistance and water sorption were utlized to examine the prepared composites. The flexural strength and wear resistance of composites with 3 wt% TiO2 nanotubes significantly increased in comparison with other composites. On the other hand, due to the stability of composite, the water sorption was decreased. Therefore, TiO2 nanotubes reinforcement could be a promising solution for the improvement of mechanical properties in dental composites.


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