Resin Containing Research Articles

Antimicrobial and Mechanical Properties of Orthodontic Acrylic Resin Containing Zinc Oxide and Titanium Dioxide Nanoparticles Supported on 4A Zeolite.

Polymethyl methacrylate (PMMA) is widely used to manufacture removable orthodontic appliances. However, since the porous structure, cold-curing acrylic resins are susceptible to bacterial adhesion and colonization. The aim of this study was to investigate the antibacterial and mechanical properties of a cold-curing PMMA resin containing ZnO and TiO2 nanoparticles supported on the 4A zeolite. ZnO and TiO2 nanoparticles supported on the 4A zeolite were synthesized. Nanoparticles were added in three compositions as ZnO/4A, TiO2/4A, and ZnO/TiO2/4A at 2wt% and 4wt% concentrations to cold-curing acrylic resin powder (SR Triplex® Cold Ivoclar Vivadent AG, FL-9494 Schaan/Liechtenstein). X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), and dynamic light scattering (DLS) were performed to investigate the nanocomposite characteristics. A direct test method was used to assess the antibacterial properties against Streptococcus mutans, Klebsiella pneumoniae, and Escherichia coli. The surface roughness of acrylic samples was measured with a profilometer. Flexural strength was evaluated by a three-point bending test, and one-way ANOVA and Tukey's post hoc tests were used for statistical evaluation of the data. A p value of less than 0.05 was considered statistically significant. XRD confirmed the accurate crystalline structure of synthesized nanoparticles; FE-SEM images showed nanoparticle dispersion within polymerized acryl. The addition of 2 and 4 wt% of ZnO/4A, TiO2/4A, and ZnO/TiO2/4A caused colony reduction in all types of tested microorganisms more than 99% and 100%, respectively. The mean flexural strengths of acrylic specimens containing 2wt% and 4wt% of synthesized nanoparticles were significantly lower than those of the resin without nanoparticles. Fabricated samples showed favorable antibacterial properties but decreased flexural strength.

Phthalonitrile Resin Containing Benzoxazine and Allyl Structures Copolymerized with BMI and Properties of their Quartz Fiber-Reinforced Composites

Copolymerization method was an efficient way to obtain polymer materials with improved performance due the combination of the advantages of each component. In this work, phthalonitrile resin containing benzoxazine and allyl structures (DBA-ph) was copolymerized with bismaleimide (BMI) and their quartz fiber (QF) reinforced composites were prepared. Results of DSC and DRA showed that DBA-ph/BMI exhibited triple-stage curing reactions and good processability. With introducing of BMI, curing reaction of DBA-ph/BMI could be initiated at lower temperature and obviously influenced by BMI content. DBA-ph/BMI/QF composites possessed relative low dielectric constants and loss, high thermal stabilities and char yield.

Denture Base PMMA Resin Containing Vanillin Inhibits Biofilm Formation of Bacteria Associated with Malodor

Dentures are prosthetic device made of polymethyl methacrylate acrylic (PMMA) resin generally used by elderly people to replace their real teeth. However, the porosity and surface irregularities of acrylic resin are undesirable aspects of the denture base that can support colonization of oral microorganisms on the denture surface, particularly those associated with malodor. Oral malodor is a common and upsetting situation frequently found in denture wearers due to inadequate denture cleaning. A large number of strategies had been employed to minimize the potential bacterial pathogens, including mechanical brushing and using chemical agents. Therefore, we have developed denture PMMA resin containing vanillin and evaluated antimicrobial potential against four species of bacteria related to oral malodor. Denture base resin samples were prepared with dimensions of 10 mm x 10 mm x 1 mm. according to the amount of incorporating vanillin concentrations (0.1%, 0.5% and 1.0% w/w) and coated with saliva. Then, the biofilm formation of four species of bacteria (Porphyromonas gingivalis ATCC 33277, Aggregatibacter actinomycetemcomitans ATCC 33384, Fusobacterium nucleatum ATCC 25586, and Actinomyces viscosus ATCC 19246) was performed on resin samples in anaerobically condition for 48-72 h. Denture resin sample without vanillin was prepared in the same way and used as a control. The quantity of vital biofilm was assessed by WST Microbial Cell Counting Kit (Dojindo Molecular Technologies, USA). Kruskal-Wallis test followed by Dunn’s method were applied for statistical analysis. The results showed that in the groups of 0.5% and 1.0% w/w vanillin, significant decreases of biofilm mass were observed in all tested bacteria (P. gingivalis, A. actinomycetemcomitans, and F. nucleatum) compared with controls, except for A. viscosus. Approximately 30% to 38% bacterial biofilm reduction was demonstrated at 1.0% w/w vanillin on three species of bacteria, whereas 7% to 27% biofilm decreases were observed at 0.5% vanillin. No significant biofilm reduction was observed in A. viscosus. This conforms to our previous studies which revealed the antimicrobial properties of denture PMMA resin containing vanillin on respiratory pathogens and oral yeast. Denture base resin consisting of vanillin may be considered as a promising dental appliance for the use to prevent or solve the problem of oral malodor in patients who wear dentures.

3D-Printable Denture Base Resin Containing SiO2 Nanoparticles: An In Vitro Analysis of Mechanical and Surface Properties.

To evaluate the flexural strength (FS), impact strength (IS), surface roughness (Ra), and hardness of 3D-printed resin incorporating silicon dioxide nanoparticles (SNPs). A total of 320 acrylic specimens were fabricated with different dimensions according to test specifications and divided into a control group of heat denture base resin, and 3 test groups (80/test (n = 10) of unmodified, 0.25 wt%, and 0.5 wt% SNPs modified 3D-printed resin. 10,000 thermal cycles were performed to half of the fabricated specimens. FS, IS (Charpy impact), Ra, and hardness were evaluated and the collected data was analyzed with ANOVA followed by Tukey's post hoc test (α = 0.05). Incorporating SNPs into 3D-printed resin significantly increased the FS, IS (at 0.5%) and hardness compared to unmodified 3D-printed resin (p < 0.001). However, the FS of pure 3D-printed and 3D/SNP-0.50% resin and IS of all 3D-printed resin groups were significantly lower than the control group (p < 0.0001). Hardness of 3D/SNP-0.25% and 3D/SNP-0.50% was significantly higher than control and unmodified 3D-printed resin (p < 0.0001), with insignificant differences between them. The Ra of all 3D-printed resin groups were significantly higher than control group (p < 0.001), while insignificant difference was found between 3D-printed groups. Thermal cycling significantly reduced FS and hardness for all tested groups, while for IS the reduction was significant only in the control and 3D/SNP-0.50% groups. Thermal cycling significantly increased Ra of the control group and unmodified 3D-printed resin (p < 0.001). The addition of SNPs to 3D-printed denture base resin improved its mechanical properties while Ra was not significantly altered. Thermal cycling adversely affected tested properties, except IS of unmodified 3D-printed resin and 3D/SNP-0.25%, and Ra of modified 3D-printed resin.

A Frequency-Reconfigurable Inverted-L Antenna Made of Pure Water

A pure-water inverted-L antenna with frequency reconfigurability is proposed in this letter. The radiation from the cutoff region of high-permittivity dielectric waveguide is here utilized in the proposed water antenna to realize the similar performance of a metal inverted-L antenna. According to the operational principle, the working frequency of proposed water antenna is mainly determined by the cross section of water rod rather than its length. It is found that a wide tuning range from 1.1 to 2.2 GHz can be achieved when the radius of cross section is changed from 2.5 to 5 mm. Two states with three-dimensional printed transparent double-layer resin container are selected to implement the frequency reconfigurability. By controlling the filling status of water, i.e., only occupying inner layer (state 1) or the whole container (state 2), the radius of water rod is altered. The operational frequency band of fabricated water antenna can be tuned from 1.41–2.04 GHz (state 1) to 1.07–1.33 GHz (state 2). The proposed antenna is intrinsically different from those conventional reconfigurable water wire antennas where length is usually tuned to attain frequency agility. Both wide frequency tuning range and stable broadside radiation are here achieved.

Study on the Synthesis of Water-dispersible Acrylic Resin Containing Hydroxyl Group`

Hydroxy acrylic resin is a long-chain polymer material formed by cleavage and recombination of double bonds of various acrylates and methacrylates under the action of initiators. Among them, MMA and BA provide the rigidity of the molecular chain and For flexibility, HEMA provides the hydroxyl groups required for cross-linking and curing, and MAA gives the resin water solubility. By rationally designing different monomer dosages, resin products with high gloss and high hardness are prepared, and through paint making experiments, the paint film Performance is tested.

Development of Antibacterial Dental Resins Containing Bis-Quaternary Ammonium Betulin-Based Dimethacrylate

Development of Antibacterial Dental Resins Containing Bis-Quaternary Ammonium Betulin-Based Dimethacrylate

Detailed Thermal, Fire, and Mechanical Study of Silicon-Modified Epoxy Resin Containing Humic Acid and Other Additives

Detailed Thermal, Fire, and Mechanical Study of Silicon-Modified Epoxy Resin Containing Humic Acid and Other Additives

A Novel Developed Bioactive Composite Resin Containing Silver/Zinc Oxide (Ag/ZnO) Nanoparticles as an Antimicrobial Material against Streptococcus mutans, Lactobacillus, and Candida albicans.

Aim The objectives of this study were to develop a new bioactive composite resin containing silver/zinc oxide (Ag/ZnO) nanoparticles and investigate the effects on mechanical, cytotoxic, biocompatibility, and antimicrobial properties. Materials and Methods Disc-shaped specimens were prepared from composite with and without nanoparticles in separate culture media containing Streptococcus mutans, Lactobacillus, and Candida albicans. Bracket bonding evaluation was performed on composite without nanoparticles (O), composite containing ZnO (Z) nanoparticles, composite containing ZnO nanoparticles and silver ions (A&Z), and composite containing Ag/ZnO nanoparticles (AZ) synthesized using optical precipitation. Results Composite resin with nanoparticles (AZ, A&Z, and Z) showed significant antimicrobial properties (P < 0.05). The mean shear bond strength of A&Z composite resin (13.61 ± 0.73 MPa) was significantly less than that of conventional composite resin (19.03 ± 4.12 MPa) (P < 0.05). In addition, the mean shear bond strength of AZ composite resin (20.49 ± 1.03 MPa) was significantly higher than that of Z (16.35 ± 1.03 MPa) and A&Z composite resins. Conclusions Incorporation of ZnO nanoparticles and their compounds into orthodontic composite resins induced antibacterial properties against oral pathogens, and of all these nanoparticles, the AZ group exhibited the best antimicrobial activity and highest shear bond strength.

Broadband water-based metamaterial absorber for millimeter-wave, high-power applications

An all-dielectric metamaterial absorber based on water resonator encapsulated in resin container is proposed. The absorber can afford the maximum absorption up to 98% at 190 GHz, as well as the wide absorption frequency range from 115 GHz to 300 GHz and a nearly 90% relative absorption bandwidth. The role of water resonator sealed in the resin shell in improving absorption capability is demonstrated by the comparison result that the proposed absorber is superior to pure water or pure resin absorber with the same dimension and interpreted by a further study on the fields and power loss density distributions. Moreover, the proposed absorber can remain excellent absorption performance even for the oblique incidence with large angles. Besides the outstanding absorption performance, the proposed absorber has the advantage of low cost endowed by the use of water, which makes it promising for EM compatibility in the millimetre-wave and high-power cases.

Dynamic-Mechanical Properties and Thermal Conductivity of a Polyester Resin Containing Modified Graphene Oxide Particles

فرضیه‌: رزین پلی‌استر غیراشباع کاربردهای فراوانی در صنعت کامپوزیت دارد. در قطعه‌های ضخیم ساخته‌شده با این رزین، گرمای زیادی در زمانی کوتاه حین پخت آزاد می‌شود، از طرفی ضریب انتقال گرمای کم این رزین سبب افزایش دما در مرکز قطعه‌ها به بیش از 200 درجه سلسیوس می‌شود. اختلاف دمای زیاد میان مرکز و دیواره‌های نمونه موجب ایجاد تنش‌های داخلی در نمونه‌های ضخیم می‌شود، بنابراین افزودن ذرات با رسانندگی گرمایی زیاد می‌تواند در برطرف‌کردن این نقص کمک شایانی کند. بنابراین، در پژوهش حاضر از ذرات گرافن اکسید برای بهبود خواص رزین پلی‌استر غیر‌اشباع استفاده شده است.روش‌ها: در این مطالعه، از گرافن اکسید و گرافن اکسید اصلاح‌شده برای بهبود رسانندگی گرمایی و خواص دینامیکی رزین پلی‌استر غیراشباع استفاده شد. اثر افزودن ذرات گرافن اکسید و گرافن اکسید اصلاح‌شده در مقدارهای 0.05 و 0.3% وزنیبر رسانندگی گرمایی و خواص دینامیکی رزین پلی‌استر غیراشباع با دستگاه اندازه‌گیری رسانندگی گرمایی جامدات و آزمون DMA مطالعه شد. یافته‌ها: نتایج نشان داد، اصلاح‌کننده سیلانی می‌تواند سبب ایجاد پیوندهای کووالانسی قوی میان ذرات و رزین شود و تغییر در ضریب رسانندگی گرمایی و خواص دینامیکی شود. افزودن% 0.05 وزنی گرافن اکسید به رزین موجب افزایش %10 درصد مدول ذخیره در ناحیه شیشه‌ای شد. در صورتی که افزودن همین مقدار گرافن اکسید اصلاح‌شده، مدول ذخیره را %36 افزایش داد. اصلاح‌کننده سیلانی موجب پراکنش بهتر ذرات گرافن اکسید در رزین می‌شود و این موضوع سبب ایجاد برهم‌کنش‌های قوی‌تر میان ذرات و شبکه رزین‌ شده که به‌طور شایان توجهی مدول ذخیره رزین را افزایش می‌دهد. پراکنش بهتر ذره در رزین می‌تواند مقاومت گرمایی سطحی ذرات را افزایش دهد. بنابراین، رسانندگی گرمایی در مقایسه با رسانندگی گرمایی گرافن اکسید اصلاح‌نشده کاهش می‌یابد.

Antifungal Activity of Denture Base Resin Containing Nanozirconia: In Vitro Assessment of Candida albicans Biofilm.

Objective To evaluate the antimicrobial effects of different concentrations of zirconium dioxide nanoparticles (nano-ZrO2) reinforcement of poly(methyl) methacrylate (PMMA) on surface roughness and C. albicans biofilm. Methods 20 heat-polymerized acrylic resin discs were conventionally made and divided into 4 groups (n = 5) according to nano-ZrO2 concentration: control (0% filler) and 3 experimental groups (2.5% (Z2.5), 5.0% (Z5.0), and 7.5% (Z7.5)). An optical profilometer was used for surface roughness evaluation, followed by Candida adherence assay. Specimens were sterilized, then immersed in cultured yeast (C. albicans), and incubated at 37°C for 48 hours. After that, discs were rinsed before extracting the clustered pellets of Candida. The attached C. albicans was counted using the direct method after spreading on agar media and incubating for 48 hours. Statistical analysis was performed using one-way ANOVA and Tukey's post hoc test at α = 0.05. Results Surface roughness was significantly increased with all modified groups compared with control (P < 0.01), which showed the lowest roughness value (0.027 ± 0.004 μm). There was no significant difference in the roughness value among reinforced groups (2.5, 5.0, and 7.5%) (P > 0.05), with Z7.5 showing the highest roughness value (0.042 ± 0.004 μm). Candida count was reduced as the nano-ZrO2 increased but not significantly (P=0.15). Conclusions The addition of different concentrations of nano-ZrO2 particles to PMMA increased the surface roughness compared with control; in contrast, insignificant reduction of C. albicans biofilm was detected.

Investigating the Electrical Properties of Epoxy Resin Containing MWCNT–PANI with a Core-Shell Morphology: Synthesis and Characterization

Investigating the Electrical Properties of Epoxy Resin Containing MWCNT–PANI with a Core-Shell Morphology: Synthesis and Characterization

Anti-Microbial and Remineralizing Properties of Self-Adhesive Orthodontic Resin Containing Mesoporous Bioactive Glass.

Self-adhesive resins (SARs) contain adhesives, which simplify the procedures of resin application, and primers, which provide sufficient bonding ability. In this study, mesoporous bioactive glass nanoparticles (MBN) were added to a SAR to easily improve the physical properties and remineralization ability. The experimental resins comprised 1%, 3%, and 5% MBN mixed in Ortho Connect Flow (GC Corp, Tokyo, Japan). As the MBN content in the SAR increased, the microhardness increased, and a statistically significant difference was observed between the cases of 1% and 5% MBN addition. Shear bond strength increased for 1% and 3% MBN samples and decreased for 5% MBN. The addition of MBN indicated a statistically significant antibacterial effect on both gram-negative and gram-positive bacteria. The anti-demineralization experiment showed that the remineralization length increased with the MBN content of the sample. Through the above results, we found that SAR containing MBN has antibacterial and remineralization effects. Thus, by adding MBN to the SAR, we investigated the possibility of orthodontic resin development, wherein the strength is enhanced and the drawbacks of the conventional SAR addressed.

Recent Designs on Resin Containers of Photocuring 3D Printer

Background: Photocuring 3D printing is a highly efficient additive manufacturing technology for machining complex object geometries. Resin container, a core component of photocuring 3D printer, plays a significant role in solving the problems about resin supply, temperature control, peeling method and membrane pressure during the curing process. Thus, the resin container has been paid great attention to optimize the curing process. Objective: To offer some new designs of resin container which contribute to solve problems about resin supply, temperature control, peeling method and membrane pressure. Provide the reader with a new idea that the function of resin containers cannot be ignored during 3d printing. Moreover, stimulate the reader's thoughts about how can designs of resin containers be further improved. Methods: This paper sketches out the strengths and weaknesses of these designs of resin containers with a more critical eye. And show their similarities and differences in a more concise form. Results: The strengths and weaknesses of these designs of resin containers in photocuring 3D printing are summarized. There is no doubt that a suitable resin container contributes to solve the problems about resin supply, temperature control, peeling method and membrane pressure. It helps to stimulate the reader's thoughts on the selection of resin containers for printing optimization. Conclusion: Researchers should pay more attention to the new designs of resin containers which are easy to be ignored but have great significance. Some new resin containers will be invented to solve problems about resin supply, temperature control, peeling method and membrane pressure during the curing process.

Current state and future scope of additive manufacturing technologies via vat photopolymerization

Abstract The ever increasing demand for new products accelerate the growth of manufacturing technologies. Additive manufacturing is the most popular among them due to its ability to print complex customized geometries. Applications were limited to rapid prototyping at earlier stages which limited its potential. But the technology advancements and researches helped in taking the technology to the next level of customized functional end use products. The applications are diversified into various fields including aerospace, medical, automobiles etc. Traditional layer by layer making of specified products are slow and lacks surface quality. In this paper, the current state, advancements and future of photopolymerization based additive manufacturing is explored. Stereolithography, the first commercial additive manufacturing technology is based on the principle of vat photopolymerization. Process speed improvement of 100 times is achieved using Continuous Liquid Interface Production. This technology lifted three dimensional objects continuously from the resin pool by proper control of oxygen and light. Dual wavelength photoinitiation and photoinhibition method printed objects at a speed of 2 m/hour approximately. The latest trend, volumetric additive manufacturing where simultaneous printing of all points within the target geometry is made possible by the rotation of resin container to dynamic light patterns using digital light projection system. The future of additive manufacturing is promising and in fact Industry 4.0′s major component.

Synthesis, Polymerization Kinetics and Thermal Properties of Benzoxazine Resin Containing ortho-Maleimide Functionality

A benzoxazine monomer with ortho-maleimide functionality has been synthesized using ortho-maleimide functional phenol, aniline and paraformaldehyde as starting materials. The chemical structure of this benzoxazine monomer is verified by 1H and 13C nuclear magnetic resonance (NMR) and Fourier transform infrared (FT-IR) spectroscopies, elemental analysis as well as high-resolution mass spectrometry. The polymerization behavior of benzoxazine has been studied by differential scanning calorimetry (DSC) and in situ FT-IR. Besides, the kinetic parameters have been calculated by non-isothermal DSC with different heating rates. The apparent activation energy value of the ortho-maleimide functional benzoxazine is calculated to be 72.43 kJ/mol based on the Starink method. In addition, our predicted thermograms based on the developed model fit well with the curves obtained from experimental DSC results. Moreover, DSC and thermogravimetric analyses (TGA) are used to determine the thermal properties of the cross-linked thermoset. The resulting polybenzoxazine derived from ortho-maleimide functional shows excellent thermal stability (Tg of 247 °C; Td5 of 333 °C), evidencing its great potential application in high-performance fields.

Study on Properties of Heat-Resistant Hybrid Resin Containing Silicon and Composites

In recent years, one kind of novel hybrid polymer containing silicon has already been reported in the field of high-temperature resistance polymer. Gradually, it has been a research hotspot in the field of high-performance matrix resins because of excellent heat resistance and dielectric properties. The composite was prepared by M-aminophenylacetylene terminated polymethyldiphenylethynyl silane (MDPES-2) as a matrix and nonalkali glass cloth as reinforced material using a hot press process. The cure reaction of MDPES-2 was characterized. Meanwhile, heat resistance, mechanical properties, and dielectric properties of MDPES-2 composites were systematically studied in this paper. The results showed that flexural strength at room temperature is 321 MPa and flexural strength retention at 240°C was 98.3%. Flexural strength retention after thermal treatment at 500°C for 7 min was 84%. In addition, ε and dielectric dissipation factor ( tan δ ) were 3.9 and 2.0 × 10 − 3 (10 GHz).

Study on the Synthesis and Thermal Stability of Silicone Resin Containing Trifluorovinyl Ether Groups.

Silicone resin is a high-temperature resistant material with excellent performance. The improvement of its thermal stability has always been the pursuit of researchers. In this paper, a sequence of silicone resins containing trifluorovinyl ether groups were prepared by the co-hydrolysis-polycondensation of methyl alkoxysilane monomers and {4-[trifluorovinyl(oxygen)]phenyl}methyldiethoxysilane. The structures of the silicone resins were characterized by FT-IR and 1H NMR. The curing process of them was studied by DSC and FT-IR spectra, and results showed that the curing of the resins included the condensation of the Si-OH groups and the [2 + 2] cyclodimerization reaction of the TFVE groups, which converted to perfluorocyclobutane structure after curing. The thermal stability and thermal degradation behavior of them was studied by TGA and FT-IR spectra. Compared with the pure methyl silicone resin, silicone resins containing TFVE groups showed better thermal stability under both N2 and air atmosphere. Their hydrophobic properties were characterized by contact angle test. Results showed that PFCB structure also improved the hydrophobicity of the silicone resin.

Effect of 4-META/MMA-TBB Resin Containing Calcium Chloride Dihydrate on Dentin Remineralization and Its Mechanical Properties

Effect of 4-META/MMA-TBB Resin Containing Calcium Chloride Dihydrate on Dentin Remineralization and Its Mechanical Properties