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International Journal of Nanomedicine 2022Though acrylic resins possess many useful properties, denture fracture is nevertheless a familiar issue.
BACKGROUND
Though acrylic resins possess many useful properties, denture fracture is nevertheless a familiar issue.
OBJECTIVE
This study aimed to determine the effect of low-percent recycled Zirconia nanoparticles as filler on the transverse strength, impact strength, surface hardness, water sorption, and solubility of resin using the sprinkle cold-curing technique.
MATERIALS AND METHODS
Various formulae were prepared and mixed with PMMA (polymer) powder containing varying percentages (0.01%, 0.1%, 0.3%, and 0.5%) of recycled ZrO2NPs to mono-methyl methacrylate (MMA monomer). A 2-hydroxyethyl-methacrylate (HEMA) agent was used to functionalize recycled zirconia (ZrO) nano-fillers. X-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, and dynamic light scattering were used to characterize the samples. For mechanical tests, standard metallic moulds (according to American Dental Association specification no. 27) were machined for 60 specimens' preparation, 12 for each percent (zero, 0.01%, 0.1%, 0.3%, and 0.5%). A one-way ANOVA test was used to compare the five groups for parametric data, while the Kruskal-Wallis test was employed for nonparametric data. The 0.05 value was accepted as the significance level. All formulae were tested for cytotoxicity at 24 and 48 hours on WI38 normal lung cell lines.
RESULTS
The XRD analysis demonstrated the tetragonal crystallographic structure of the recycled zirconia nanoparticles. Incorporating a low percentage of recycled ZrO nanoparticles (0.01%, 0.1%, 0.3%, and 0.5%) improved the tested properties of PMMA to different degrees in a significant and non-significant pattern, while the optimal tested percent was 0.3%.
CONCLUSION
The 0.3% percentage of recycled zirconia nanoparticles maintained and improved the physical and mechanical properties of acrylic resin. Recycled ZrO/PMMA nanocomposite is a synergistic candidate due to its economic return and clinical application safety.
Topics: Acrylic Resins; Denture Bases; Materials Testing; Methacrylates; Polymethyl Methacrylate; Powders; Surface Properties; Water; Zirconium
PubMed: 36199477
DOI: 10.2147/IJN.S374258 -
Scientific Reports Aug 2022The aim of this study is to fabricate a new scaffold appropriate for tissue regeneration with antimicrobial activity and ability of controlled drug delivery. In this...
The aim of this study is to fabricate a new scaffold appropriate for tissue regeneration with antimicrobial activity and ability of controlled drug delivery. In this regard, scaffold nanofibers were produced using poly (methyl methacrylate) (PMMA), Mo as a Keplerate polyoxometalate and metronidazole. The final scaffolds, obtained by electrospinning, represent the intrinsic features including exceptional doubling tensile strength, high hydrophilicity (126 ± 5.2° to 83.9 ± 3.2° for contact angle and 14.18 ± 0.62% to 35.62 ± 0.24% for water uptake), proper bioactivity and cell adhesion. Moreover, the addition of Mo and metronidazole enhances the biodegradation rate of resulted scaffolds compared to the pure PMMA membrane. The controlled release of metronidazole over 14 days efficiently inhibits the colonization of anaerobic microorganisms. Overall, the results demonstrate high potential of Mo and metronidazole-loaded PMMA scaffold for guided bone regeneration/guided tissue regeneration.
Topics: Anions; Bone Regeneration; Cell Adhesion; Metronidazole; Nanofibers; Polyelectrolytes; Polymethyl Methacrylate; Tissue Engineering; Tissue Scaffolds
PubMed: 36002474
DOI: 10.1038/s41598-022-18622-w -
Molecules (Basel, Switzerland) Sep 2022Core-shell nanocomposites comprising barium titanate, BaTiO (BTO), and poly(methyl methacrylate) (PMMA) chains grafted from its surface with varied grafting densities...
Core-shell nanocomposites comprising barium titanate, BaTiO (BTO), and poly(methyl methacrylate) (PMMA) chains grafted from its surface with varied grafting densities were prepared. BTO nanocrystals are high-k inorganic materials, and the obtained nanocomposites exhibit enhanced dielectric permittivity, as compared to neat PMMA, and a relatively low level of loss tangent in a wide range of frequencies. The impact of the molecular dynamics, structure, and interactions of the BTO surface on the polymer chains was investigated. The nanocomposites were characterized by broadband dielectric and vibrational spectroscopies (IR and Raman), transmission electron microscopy, differential scanning calorimetry, and nuclear magnetic resonance. The presence of ceramic nanoparticles in core-shell composites slowed down the segmental dynamic of PMMA chains, increased glass transition temperature, and concurrently increased the thermal stability of the organic part. It was also evidenced that, in addition to segmental dynamics, local β relaxation was affected. The grafting density influenced the self-organization and interactions within the PMMA phase, affecting the organization on a smaller size scale of polymeric chains. This was explained by the interaction of the exposed surface of nanoparticles with polymer chains.
Topics: Barium; Molecular Dynamics Simulation; Nanoparticles; Polymers; Polymethyl Methacrylate
PubMed: 36234912
DOI: 10.3390/molecules27196372 -
Scientific Reports Oct 2023Poly(lactic acid) (PLA) is gaining popularity in manufacturing due to environmental concerns. When comparing to poly(methyl methacrylate) (PMMA), PLA exhibits low...
Poly(lactic acid) (PLA) is gaining popularity in manufacturing due to environmental concerns. When comparing to poly(methyl methacrylate) (PMMA), PLA exhibits low melting and glass transition temperature (T). To enhance the properties of these polymers, a PMMA/PLA blend has been introduced. This study aimed to investigate the optimal ratio of PMMA/PLA blends for potential dental applications based on their mechanical properties, physical properties, and biocompatibility. The PMMA/PLA blends were manufactured by melting and mixing using twin screw extruder and prepared into thermoplastic polymer beads. The specimens of neat PMMA (M100), three different ratios of PMMA/PLA blends (M75, M50, and M25), and neat PLA (M0) were fabricated with injection molding technique. The neat polymers and polymer blends were investigated in terms of flexural properties, T, miscibility, residual monomer, water sorption, water solubility, degradation, and biocompatibility. The data was statistically analyzed. The results indicated that T of PMMA/PLA blends was increased with increasing PMMA content. PMMA/PLA blends were miscible in all composition ratios. The flexural properties of polymer blends were superior to those of neat PMMA and neat PLA. The biocompatibility was not different among different composition ratios. Additionally, the other parameters of PMMA/PLA blends were improved as the PMMA ratio decreased. Thus, the optimum ratio of PMMA/PLA blends have the potential to serve as novel sustainable biomaterial for extensive dental applications.
Topics: Polymethyl Methacrylate; Biocompatible Materials; Polyesters; Polymers; Water
PubMed: 37803035
DOI: 10.1038/s41598-023-44150-2 -
Sensors (Basel, Switzerland) Nov 2021We designed simply fabricated, highly sensitive, and cost-effective dual-polymer-coated Fabry-Perot interferometer (DFPI)-based temperature sensors by employing...
We designed simply fabricated, highly sensitive, and cost-effective dual-polymer-coated Fabry-Perot interferometer (DFPI)-based temperature sensors by employing thermosensitive polymers and non-thermosensitive polymers, as well as different two successive dip-coating techniques (stepwise dip coating and polymer mixture coating). Seven sensors were fabricated using different polymer combinations for performance optimization. The experiments demonstrated that the stepwise dip-coated dual thermosensitive polymer sensors exhibited the highest sensitivity (2142.5 pm °C for poly(methyl methacrylate)-polycarbonate (PMMA_PC) and 785.5 pm °C for poly(methyl methacrylate)- polystyrene (PMMA_PS)). Conversely, the polymer-mixture-coated sensors yielded low sensitivities (339.5 pm °C for the poly(methyl methacrylate)-polycarbonate mixture (PMMA_PC mixture) and 233.5 pm °C for the poly(methyl methacrylate)-polystyrene mixture (PMMA_PS mixture). Thus, the coating method, polymer selection, and thin air-bubble-free coating are crucial for high-sensitivity DFPI-based sensors. Furthermore, the DFPI-based sensors yielded stable readouts, based on three measurements. Our comprehensive results confirm the effectiveness, reproducibility, stability, fast response, feasibility, and accuracy of temperature measurements using the proposed sensors. The excellent performance and simplicity of our proposed sensors are promising for biomedical, biochemical, and physical applications.
Topics: Polymers; Polymethyl Methacrylate; Polystyrenes; Reproducibility of Results; Temperature
PubMed: 34833708
DOI: 10.3390/s21227632 -
Journal of Oral Science Aug 2019The aim of the present study is to evaluate the wear resistance and microhardness of various interim fixed prosthesis materials with different chemical compositions and...
The aim of the present study is to evaluate the wear resistance and microhardness of various interim fixed prosthesis materials with different chemical compositions and curing methods. One heat-cured and four self-cured acrylic resins, and three self-cured, one light-cured, and one dual-cured composite-based materials were tested. For microhardness, samples from each group were tested after storing either at 37°C in artificial saliva for 7 days, followed by thermocycling, or in distilled water solution at 37°C for 24 h. For the evaluation of wear, the remaining samples were evaluated using a 3D scanner and a surface analysis program before loading in the chewing simulator and after every 10,000 cycles. There was a significant difference in wear behavior among the materials tested at both 10,000 and 20,000 cycles (P < 0.001). Microhardness and wear resistance were significantly different between acrylic and composite materials.
Topics: Acrylic Resins; Composite Resins; Hardness; Materials Testing; Polymethyl Methacrylate; Prostheses and Implants; Surface Properties
PubMed: 31341123
DOI: 10.2334/josnusd.18-0323 -
Translational Vision Science &... Dec 2020To evaluate titanium (Ti) sputtering of the poly(methyl methacrylate) (PMMA) stem of the Boston Keratoprosthesis (BK) as a method to enhance interfacial adhesion between...
PURPOSE
To evaluate titanium (Ti) sputtering of the poly(methyl methacrylate) (PMMA) stem of the Boston Keratoprosthesis (BK) as a method to enhance interfacial adhesion between the PMMA and the recipient corneal tissue.
METHODS
PMMA specimens were plasma treated with Ar/O and coated with Ti using a DC magnetron sputtering instrument. The topography and hydrophilicity of the surfaces were characterized using atomic force microscopy and a water contact angle instrument, respectively. Scratch hardness and adhesion of the Ti film were measured using a mechanical tester. Biocompatibility assessments were performed using cultured human corneal fibroblasts and whole blood ex vivo. The optical quality of the Ti sputtered BK was evaluated using a custom-made optical bench.
RESULTS
By contact angle studies, the Ti coating improved PMMA hydrophilicity to match that of medical-grade Ti (Ti-6Al-4V-ELI). Ti sputtering of contact surfaces resulted in a plate-like morphology with increased surface roughness, without impacting the transparency of the BK optical component. Scratch testing indicated that the mechanical behavior of the Ti coating was similar to that of casted Ti, and the coating was stable in pull-off adhesion testing. Sputtered Ti film was highly biocompatible based on tests of cell viability, adhesion, proliferation, differentiation, collagen deposition, and keratocan expression, the properties of which exceeded those of uncoated PMMA and did not induce increased complement activation.
CONCLUSIONS
Titanium coating of the BK stem generated a mechanically and biologically favorable interface, which may help to enhance corneal stromal adhesion and biocompatibility.
TRANSLATIONAL RELEVANCE
Improving the biocompatibility of the BK PMMA stem may improve long-term outcomes of implantation.
Topics: Cornea; Humans; Polymethyl Methacrylate; Prostheses and Implants; Surface Properties; Titanium
PubMed: 33442495
DOI: 10.1167/tvst.9.13.41 -
Orthopaedics & Traumatology, Surgery &... Dec 2022Antibiotics differ in their elution characteristics from bone cement. But no such data is available on piperacillin and tazobactam. Therefore, we performed an in vitro... (Observational Study)
Observational Study
BACKGROUND
Antibiotics differ in their elution characteristics from bone cement. But no such data is available on piperacillin and tazobactam. Therefore, we performed an in vitro observational study to examine (1) in vitro elution characteristics of piperacillin and tazobactam from bone cement, (2) their biological activity using minimum inhibitory concentration and (3) elution characteristics and biological activity when combined with gentamicin in bone cement.
HYPOTHESIS
The null hypothesis was that piperacillin and tazobactam after elution from bone cement can achieve concentrations higher than minimum inhibitory concentration.
MATERIAL AND METHODS
Forty milligrams bone cement was mixed with the following combination of antibiotics: without any antibiotic (sample A, control), 4g/0.50g piperacillin/tazobactam (sample B), 6g/0.75g piperacillin/tazobactam (sample C), 8g/1.0g piperacillin/tazobactam (sample D) and 4g/0.50g piperacillin/tazobactam and 400mg gentamicin (sample E). Samples were analysed on reverse-phase ultra-high-performance liquid chromatography. Antibacterial activity in the elute were tested against standard American Type Culture Collection (ATCC) strains.
RESULTS
Detectable drug elution for piperacillin and tazobactam was seen till 21days. Peak drug levels for all formulations were seen at 48hours (140.8 & 297.5μg/mL for samples B of piperacillin and tazobactam respectively). About 0.83-1.24% of piperacillin and 23.17-29.17% of tazobactam were released from the samples. Gentamicin improved elution of piperacillin and tazobactam: 140.8 vs. 919.9μg/mL (p=0.000) for samples B & E of piperacillin respectively and 297.5 & 1138.4μg/mL (p=0.001) for samples B & E of tazobactam respectively at 2days. Sample E showed complete inhibition of tested microorganisms, while B sample was microbiologically less active compared to E on day 5.
CONCLUSIONS
Piperacillin and tazobactam eluted successfully from bone cement and also retained antimicrobial activity after elution. Maximum elution was seen up to day 2 after which it reduced drastically. Antimicrobial action was seen up to 7days.
LEVEL OF EVIDENCE
III; comparative study.
Topics: Humans; Gentamicins; Polymethyl Methacrylate; Penicillanic Acid; Bone Cements; Piperacillin; Tazobactam; Piperacillin, Tazobactam Drug Combination; Anti-Bacterial Agents; Microbial Sensitivity Tests
PubMed: 35123032
DOI: 10.1016/j.otsr.2022.103230 -
Journal of Chromatography. A Feb 2021With advances in the design and fabrication of nanofluidic devices during the last decade, there have been a few reports on nucleic acid analysis using nanoscale...
With advances in the design and fabrication of nanofluidic devices during the last decade, there have been a few reports on nucleic acid analysis using nanoscale electrophoresis. The attractive nature of nanofluidics is the unique phenomena associated with this length scale that are not observed using microchip electrophoresis. Many of these effects are surface-related and include electrostatics, surface roughness, van der Waals interactions, hydrogen bonding, and the electric double layer. The majority of reports related to nanoscale electrophoresis have utilized glass-based devices, which are not suitable for broad dissemination into the separation community because of the sophisticated, time consuming, and high-cost fabrication methods required to produce the relevant devices. In this study, we report the use of thermoplastic nanochannels (110 nm x 110 nm, depth x width) for the free solution electrokinetic analysis of ribonucleotide monophosphates (rNMPs). Thermoplastic devices with micro- and nanofluidic networks were fabricated using nanoimprint lithography (NIL) with the structures enclosed via thermal fusion bonding of a cover plate to the fluidic substrate. Unique to this report is that we fabricated devices in cyclic olefin copolymer (COC) that was thermally fusion bonded to a COC cover plate. Results using COC/COC devices were compared to poly(methyl methacrylate), PMMA, devices with a COC cover plate. Our results indicated that at pH = 7.9, the electrophoresis in free solution resulted in an average resolution of the rNMPs >4 (COC/COC device range = 1.94 - 8.88; PMMA/COC device range = 1.4 - 7.8) with some of the rNMPs showing field-dependent electrophoretic mobilities. Baseline separation of the rNMPs was not possible using PMMA- or COC-based microchip electrophoresis. We also found that COC/COC devices could be assembled and UV/O activated after device assembly with the dose of the UV/O affecting the magnitude of the electroosmotic flow, EOF. In addition, the bond strength between the substrate and cover plate of unmodified COC/COC devices was higher compared to PMMA/COC devices. The large differences in the electrophoretic mobilities of the rNMPs afforded by nanoscale electrophoresis will enable a new single-molecule sequencing platform we envision, which uses molecular-dependent electrophoretic mobilities to identify the constituent rNMPs generated from an intact RNA molecule using a processive exonuclease. With optimized nanoscale electrophoresis, the rNMPs could be identified via mobility matching at an accuracy >99% in both COC/COC and PMMA/COC devices.
Topics: Electricity; Electroosmosis; Electrophoresis, Microchip; Hydrogen-Ion Concentration; Nanotechnology; Plastics; Polymethyl Methacrylate; Ribonucleotides; Water
PubMed: 33477027
DOI: 10.1016/j.chroma.2021.461892 -
The Journal of Prosthetic Dentistry Nov 2023Which disinfection protocol provides optimal water contact angle and microhardness for computer-aided design and computer-aided manufacturing (CAD-CAM) polymethyl...
STATEMENT OF PROBLEM
Which disinfection protocol provides optimal water contact angle and microhardness for computer-aided design and computer-aided manufacturing (CAD-CAM) polymethyl methacrylate (PMMA) materials is unclear.
PURPOSE
The purpose of this in vitro study was to evaluate the effect of different disinfection protocols (1% sodium hypochlorite, denture cleanser gel, and effervescent tablet) on the water contact angle and microhardness of different CAD-CAM PMMA denture base materials by comparing them with a heat-polymerized PMMA.
MATERIAL AND METHODS
Disk-shaped specimens (Ø10×2 mm) were fabricated from 3 different CAD-CAM PMMAs-AvaDent (AV), Merz M-PM (M-PM), and Polident (Poli)-and a heat-polymerized PMMA (Vynacron) (CV) (n=21). Three disinfection protocols (1% sodium hypochlorite [HC], denture cleanser gel [GEL], an effervescent tablet [TAB]) were applied to simulate 180 days of cleansing. The water contact angle and microhardness of specimens were measured before and after disinfection and compared by using a 2-way ANOVA (α=.05).
RESULTS
For water contact angle, material (P=.010) and disinfection protocol (P=.002) had a significant effect. The material (P<.001), disinfection protocol (P=.001), and their interaction (P<.001) significantly affected the microhardness after disinfection. When the condition after disinfection was compared with that before disinfection, the water contact angle increased significantly in all material-disinfection protocol pairs (P≤.025), and microhardness increased significantly in all material-disinfection protocol pairs (P≤.040), except for GEL- (P=.689) or TAB-applied (P=.307) AV, HC-applied M-PM (P=.219), and TAB-applied Poli (P=.159).
CONCLUSIONS
The material and disinfection protocol affected the water contact angle of all tested PMMAs after disinfection, resulting in more hydrophobic surfaces for heat-polymerized or CAD-CAM PMMAs. The microhardness of heat-polymerized PMMA was less than that of all CAD-CAM PMMAs after disinfection, regardless of the protocol.
Topics: Polymethyl Methacrylate; Materials Testing; Denture Bases; Denture Cleansers; Disinfection; Sodium Hypochlorite; Computer-Aided Design; Surface Properties; Tablets; Water
PubMed: 35148889
DOI: 10.1016/j.prosdent.2021.12.007