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Objectives: To investigate the effects of denture cleansers on the various properties of CAD/CAM and heat-polymerized polymethyl methacrylate (PMMA). Materials and methods: Two different brands of heat-polymerized and two of milled PMMA were fabricated (n = 50), in total 200. Each group was randomly divided into five subgroups (n = 10): control groups (D1) kept in distilled water, cleaning tablets (D2, D3), neutral (D4) and acidic electrolyzed acid water (EAW) (D5). Surface roughness, hardness and flexural strength values were evaluated. Data were statistically analyzed with two-way ANOVA and Tukey post hoc test for comparison (p<0.05). Results: The milled group showed significantly lower surface roughness, greater surface hardness, and higher flexural strength values than heat polymerized denture bases (p<0.05). The denture cleansers had no significant effect on the surface roughness values of the milled specimens (p>0.05), whereas the specimens in the heat-polymerized groups and treated with D5 showed greater surface roughness values compared with the other cleaning agents (p > 0.05). The denture cleansers had no significant effect on surface hardness and flexural strength of heat polymerize groups (p > 0.05). However, D2, D3 and D5 cleaning agent decreased the hardness values of the milled group (p<0.05) and D5 cleaning agent decreased the flexural strength of the milled group (p<0.05). Conclusions: It was observed that the applied denture cleansers affected the surface roughness, surface hardness, and flexural strength values of both denture bases but within a clinically acceptable value. Clinical Relevance: CAD/CAM denture bases showed significantly higher physical and mechanical properties than to heat-polymerized base materials. Although the applied neutral EAW cleaners give desired results for denture bases, clinical studies are needed for biological compatibility. [ABSTRACT FROM AUTHOR]

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Background and Purpose: This study aimed to evaluate the flexural strength, color change and antimicrobial effect of silver–zeolite nanoparticles (NPs) in acrylic resin materials. Methods: Fifty-six disc-shaped acrylic resin samples were divided into four groups (n = 7) according to concentrations of silver–zeolite NPs (0%, 2%, 4%, 5%). Discs were contaminated with C. albicans and S. mutans. The antimicrobial effect was tested by inoculating contaminated discs on Tryptic soy agar (TSA), Sabouraud Dextrose Agar (SDA), Tryptic soy broth (TSB), and Sabouraud dextrose broth (SDB). Forty rectangular 65 × 10 × 2.5 mm acrylic resin specimens were also classified into four groups (n = 10) according to concentrations of silver–zeolite NPs. For the color change, L, a, and b values of rectangular specimens were examined with a spectrophotometer. A three-point bending test was also performed using a Devotrans device to determine the flexural bond strength of rectangular specimens. Scanning electron microscope analysis (SEM/EDX analysis) was also performed. Results: In this study, the antimicrobial effect increased with the concentration of silver–zeolite NPs added to acrylic resin discs. In our study, adding 2% silver–zeolite NPs was more effective against C. albicans. The antimicrobial effect against S. mutans increased with concentration of silver–zeolite NPs (<0.001). The colonization of C. albicans was significantly reduced by silver–zeolite NPs. A significant increase was observed in the color change as the nanoparticle percentage ratio increased (p < 0.001). The flexural strength values of the groups containing 2% and 4% nanoparticles were found to be clinically acceptable. Conclusions: The study showed that bacterial and fungal colonization is significantly reduced by adding silver–zeolite nanoparticles to acrylic resin discs. Based on its antimicrobial, physical, and mechanical properties, we recommend adding 2% silver–zeolite nanoparticles to the acrylic resin material for optimal results. [ABSTRACT FROM AUTHOR]

This review aimed to investigate the literature systematically and answer the question "Does the processing method of organic and inorganic agents incorporated into PMMA influence antimicrobial activity and cytotoxicity?". This systematic review was registered in the OpenScience Framework (osf.io/7nc28) and PRISMA guidelines were followed. The study design (PICOS) framework applied was P = polymethylmethacrylate; I = incorporation of organic and inorganic antimicrobials; C = control group; O = antimicrobial activity and cytotoxicity; and S = experimental in vitro studies. A custom search strategy was performed in Embase, Scopus, PubMed, and Science Direct databases. Studies were selected according to eligibility criteria in two steps. The risk of bias was evaluated by Joanna Briggs Institute's quasi-experimental studies tool. A qualitative analysis of the data was performed addressing: incorporation and polymerization methods, antimicrobial activity, and cytotoxicity of organic and inorganic agents added into PMMA. From a total of 1959 results, 34 studies were included in this review. The 3 organic agents evaluated showed antimicrobial efficacy and 1 was cytotoxic. Of the 31 inorganics, 4 showed no antimicrobial activity, and 8 reduced cell viability. Processing methods influenced the results. The incorporation of organic and inorganic antimicrobial agents into PMMA, depending on the processing method, changes the antimicrobial efficacy and cytotoxicity of the modified material. [ABSTRACT FROM AUTHOR]

Tissue slices can undergo distortions during processing into resin for light and electron microscopy as a result of differential shrinkage of the various tissue components, and this may necessitate removal of a considerable amount of material from the final resin‐embedded tissue block to ensure production of complete sections of the sample. To mitigate this problem, a number of techniques have been devised that ensure the sample is held flat during the final curing/polymerisation of the resin. For embedding in acrylic resins, oxygen must be excluded as it inhibits polymerisation, and methods devised for epoxy resin embedding are generally unsuitable. The method describes the preparation and use of air‐tight flat‐embedding chambers prepared from Melinex film and provides an inexpensive, technically simpler, and versatile alternative to chambers formed from either Thermanox coverslips or Aclar films that have previously been advocated for such purposes.Lay description: Tissue slices can undergo distortions during processing into resin for light and electron microscopy as a result of differential shrinkage of the various tissue components. Such distortions may necessitate removal of a considerable amount of material to ensure production of complete sections of the sample. For embedding in acrylic resins, oxygen must be excluded as it inhibits polymerisation, and methods devised for epoxy resin flat‐embedding are generally unsuitable. Air‐tight flat‐embedding chambers prepared from either Thermanox coverslips, or a combination of PTFE‐coated glass slides, polycarbonate film gaskets, and Aclar film have been advocated for such purposes. Thermanox coverslips are expensive and limited in size to 22 mm × 60 mm, and the alternative method is technically complicated. Melinex film is commercially available as 210 mm × 297 mm sheets and is approximately 1/20th the price of Thermanox and less than half the price of Aclar film. The method describes the preparation and use of embedding chambers made from Melinex film, glass slides and double‐sided adhesive tape as a technically simpler, inexpensive and versatile alternative to both Thermanox coverslips and the Aclar film method. [ABSTRACT FROM AUTHOR]

Acrylic resins are one of the most important thermoplastic resins used in various industries due to their significant properties. However, they are inherently brittle and the addition of plasticizers to them is very common. In this study, the role of both Polyethylene Glycol (PEG) and Triacetin on the mechanical properties of acrylic resin has been investigated. To do so, tensile test, bending, and wear tests have been performed. To achieve the optimal mixture of plasticizers, a tensile test has been carried out, and the best percentage of the mixture has been determined. Subsequently, bending and wear tests were conducted, which showed a significant increase in the bending strength of the acrylic resin after the addition of plasticizers. Furthermore, it was found that the abrasion mechanism of the resin was significantly altered compared to its pure state. [ABSTRACT FROM AUTHOR]

Context: Acrylic resin is used in dentistry as a removable denture base. It can cause various pathologies when not properly cleaned. One of the pathologies is denture stomatitis caused by Candida albicans and Streptococcus mutans accumulation on the acrylic resin surface. Therefore, microbial agents such as denture cleansers are needed. Aims: To evaluate the characteristics of lemongrass (Cymbopogon citratus) nanoparticles as a better antibacterial and antifungal herbal ingredient and their relationship with acrylic hardness. Methods: C. citratus oil nanoparticles (LON) were synthesized and analyzed by transmission electron microscopy (TEM). Electrospray ionization tandem mass spectrometry (ESI-MS) analysis was used to analyze the characteristics of LON bioactive components. Minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) against C. albicans and S. mutans and mechanical hardness test of acrylic were performed. Results: The LON concentration of MIC and MBC against C. albicans and S. mutans was 25 and 100%, respectively. One-way ANOVA showed no significant difference between groups of LON with different concentrations (p=0.687). A paired t-test showed significant differences in acrylic resin hardness before and after treatment of LON with 100% (p=0.022) and 50% (p=0.021) concentration. There was no significant difference in hardness before and after treatment of other concentrations of LON and chlorhexidine as positive control. Conclusions: LON treatment on acrylic resin decreased the growth of C. albicans and S. mutans without altering the mechanical properties (hardness).

Acrylic resins are one of the most important thermoplastic resins used in various industries due to their significant properties. However, they are inherently brittle and addition plasticizers to them is very common. In this study, role of both Polyethylene Glycol (PEG) and Triacetin on the mechanical properties of acrylic resin have been investigated. To do so tensile test, bending and wear tests have been performed. To achieve the optimal mixture of plasticizers, a tensile test has been carried out, and the best percentage of the mixture has been determined. Subsequently, bending and wear tests were conducted, which showed a significant increase in the bending strength of the acrylic resin after the addition of plasticizers. Furthermore, it was found that the abrasion mechanism of the resin was significantly altered compared to its pure state.

Background: Adding nanoparticles as filler aims to improve the mechanical properties of acrylic resin and reduce the incidence of fracture in them. This study aimed to investigate the effect of adding zirconium oxide and titanium oxide nanoparticles to acrylic resin on its flexural strength.Methods and Materials: In this in-vitro study, surface modification of ZrO2 and TiO2 nanoparticles have been done by combining with silane coupling agent (trimethoxysilylpropyl methacrylate), and 25 samples of acrylic resin with 2.5*10*65 mm dimensions have been made. 5 groups were divided into control, 1 and 5% TiO2, 1 and 5% ZrO2. Flexural strength was evaluated by universal testing machine. Data were analyzed by One-Way ANOVA and Tukey's post hoc test. P < 0.05 was considered as statistically significant.Results: A significant increase in the flexural strength of acrylic resin modified with 1% zirconium oxide compared to the control sample was observed, with an average difference of 22.082 MPa (p

In order to investigate the effect of filling different masses of inorganic filler CeO2-ZrO2-Al2O3(CZA) powder on the anticorrosive and mechanical properties of acrylic coatings, CZA powder samples were synthesized by drying and calcination using the co-precipitation method. The obtained CZA powder was fully dispersed in acrylic resin with commonly used dispersants, defoamers and other additives available in the market, and the acrylic anticorrosive coatings with different mass fractions were prepared on treated iron plates by the scraping method. Meanwhile, the XRD, SEM and EDS methods were used to analyze the physical phase of the CZA powder samples, and the mechanical property tests and electrochemical anticorrosion property tests were utilized to evaluate the characteristics of the coatings, such as adhesion, hardness, roughness, bending performance, wear resistance, tensile strength, elongation at break and anticorrosion performance. Results showed that the as-prepared CZA powders were solid solutions and showed a tetrahedral structure. After adding CZA powder, the hardness of the coating increased from HB to 1H, the bending properties were all 1T, wear resistance was improved, and adhesion was all grade 1. CZA increased the anticorrosive properties of the coatings compared to acrylic anticorrosive coatings without CZA addition, and the best anticorrosive properties of the coatings were obtained when the mass fraction of filler addition was 10%. Overall, the acrylic anticorrosive coating had certain anticorrosive properties and could effectively prevent the corrosion of corrosive media on the material, which presented certain application prospects in the field of anti-corrosion in the future.

The continuous preparation scheme EPO-Poly-indol-nido-carborane (E-P-INDOLCAB), L100-55-Poly-indol-nido-carborane (L-P-INDOLCAB), RS-Polyindol-nido-carborane (S-P-INDOLCAB), and RL-Poly-indol-nido-carborane (R-P-INDOLCAB) were used to prepare the four types of acrylic resin-coated nido-carborane indole fluorescent polymers. After testing their spectral properties and the fluorescence stability curve trend at various acidic pH values (3.4 and 5.5, respectively), L-P-INDOLCAB and S-P-INDOLCAB were determined to be the best polymers. The stable states of the two polymers and the dispersion of the nanoparticles on the system's surface during Atomic Force Microscope (AFM) test are shown by the zeta potentials of -23 and -42 mV. The dispersion of nanoparticles on the system's surface and the stable condition of the two polymers were examined using zeta potential and atomic force microscopy (AFM). Transmission electron microscopy (TEM) can also confirm these findings, showing that the acrylic resin securely encases the interior to forman eyeball. Both polymers' biocompatibility with HELA cells was enhanced in cell imaging, closely enclosing the target cells. The two complexes displayed strong inhibitory effects on PC-3 and HeLa cells when the concentration was 20 ug/mL, as validated by subsequent cell proliferation toxicity studies. [ABSTRACT FROM AUTHOR]

Copyright of Paint & Coatings Industry (0253-4312) is the property of Paint & Coatings Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In recent years, the growing environmental awareness has prompted increased attention towards the substitution of nonrecyclable thermosetting epoxy resin composite materials with recyclable thermoplastic composite materials. The objective of this study is to utilize a laboratory‐made polymethyl methacrylate (PMMA)/methyl methacrylate (MMA) binary liquid resin (PMBLR) to prepare thermoplastic resin/glass fiber (GF) composite materials using the vacuum‐assisted perfusion method. These composites are then compared with GF‐reinforced thermosetting epoxy resin composites. The investigation reveals a significant influence of benzoyl peroxide (BPO) content on the mechanical properties of pure MMA and PMBLR casting resins, which also incorporate N‐methyl‐N‐((1‐methyl‐1H‐indol‐3‐yl) methyl) aniline (DMA) as redox composite initiators. The optimal mechanical properties for both types of casting resins are achieved at a DMA:BPO:MMA ratio of 0.5:1.2:100. Additionally, at a PMMA concentration of 24 wt% in PMBLR under this specific initiator ratio, the composites demonstrate the most desirable properties. Furthermore, a comparative analysis of PMBLR/GF composites and epoxy/GF composites indicates that the former exhibit superior 90° tensile strength, bending strength, and short beam shear strength. The fracture morphology analysis highlights discernible micro‐ductile fracture characteristics in PMBLR/GF composites, distinguishing them from epoxy/GF composites. Dynamic thermomechanical analysis (DMA) results further reveal a higher storage modulus and loss factor in PMBLR/GF composites when compared to epoxy/GF composites. Highlights: Glass fiber‐reinforced composites were fabricated at ambient temperature.A degradable PMMA/MMA binary thermoplastic resin (PMBLR) was developed as a replacement for non‐degradable epoxy.PMBLR composites exhibit enhanced strength compared to epoxy: tensile (+18.8%), bending (+27.4%), and short beam shear (+34.3%). [ABSTRACT FROM AUTHOR]

The preferred material for creating removable prosthesis is acrylic resin. for the reintegration of edentulous patients due to its good aesthetics, precise fit, low cost of equipment, and ease of clinical and laboratory manipulation. Acrylic resin exhibited relatively unsatisfactory characteristics like low impact and transverse strength. However, the acrylic resin was reinforced by adding filler materials like glass fibers or mixing two powders like zirconia and chitosan. The goal of this investigation was to explore how adding nanoscale zirconia with micrometer size of chitosan (zr-ch) filler with two percentages of 1% wt. and 5% wt. and two ratios of zr-ch (2:1 and 1:2) according to a pilot study and evaluate the surface hardness, impact and transverse strength .Ninety heat-cure acrylic samples were divided into three groups (each group 30 samples) based on the percentage weight of filler added to the acrylic mixture and the ratio between the nanoparticles of zirconia with a micrometer of chitosan particles. For control group (c) without addition, group A1 with 1% wt. and a ratio of 2:1 (zr-ch) and group A2 with 5% wt. and a ratio of 1:2. Each group was tested with impact strength, transverse strength and surface hardness (10 samples for each test). The zr-ch mixture ratio was prepared and selected according to the pilot study. A sharpy testing device was used to measure the impact strength while a hardness shore D device measured surface hardness and the final test was transverse strength which was tested by a universal Instron machine. The data were statistically analyzed by IBM SPSS statistics (version 24). The findings of the present study showed significant differences in surface hardness and transverse strength throughout the various study groups. However, the group A2 variation in impact strength was discovered to be nonsignificant, while the group A1 difference was shown to be significant. The best result for all three tests was obtained in the group A1. The adding zr-ch mixture improved surface hardness, impact and transverse strength, which improved acrylic denture base. [ABSTRACT FROM AUTHOR]

To solve the problems of low flame retardant performance in the use of acrylic resin, a flame-retardant acrylic resin coating PA-IFR was prepared by adding intumescent flame retardants (IFR) composed of ammonium polyphosphate (APP), pentaerythritol (PER) and melamine (MEL) to the acrylic resin emulsion by combining ultrasonic and mechanical stirring. The chemical structure, transmittance, hardness and flame retardant properties of PA-IFR were tested by infrared spectrometer, X-ray diffractometer, pencil hardness tester and limiting oxygen index meter. The results show that the hardness of the PA-IFR reaches 5H and the limiting oxygen index (LOI) value reaches 32.6% when the mass fraction of the FR is 30% and the formula ratio of APP/PER/MEL is 2 : 1 : 1. The acrylic resin coating prepared in this study is a flame retardant material. [ABSTRACT FROM AUTHOR]

The purpose of the research described in this article was to optimize the compositions based on hydraulic-modified binder and construction waste for waterproofing and repair of concrete or brick structures in contact with the ground, as well as the study of properties and development of the basis of the methodology for selecting the composition of such a waterproofing system. Processing of the results of the experiment was carried out by statistical and analytical methods. The research was based on a method for determining the adhesive strength of a waterproofing coating, based on the determination when the insulating layers are torn off. As a result of the calculation and experimental verification, the composition of the waterproofing material was obtained, which corresponds to an adhesive strength of 3.8 MPa; the strength of the waterproofing layer was 36–37 MPa, as well as the amounts of the main components: acrylic resin 3.9%; finely ground concrete waste 80 kg/m3; plasticizer consumption (0.38...0.39%) at the optimum moisture content of the base surface (9.7...9.8%). [ABSTRACT FROM AUTHOR]

Silica nanoparticles (SiNPs) and graphene oxide (GO) are two promising nanomaterial that have attracted considerable attention for their unique properties and applications. However, the conventional synthesis methods of SiNPs and GO often involve hazardous chemicals and high energy consumption, which pose environmental and economic challenges. Therefore, green and sustainable synthesis methods of SiNPs and GO are highly desirable. In this review, we summarize the recent advances in the green synthesis of SiNPs and GO using various natural sources, such as plants, fungi, bacteria, algae, clay, etc. We also discuss the functionalization of SiNPs and GO with acrylic resin to form hybrid nanocomposites for anti-corrosion applications. The advantages and challenges of these green methods are highlighted, and the future prospects are outlined. This review aims to provide a comprehensive overview of the current state-of-the-art in the green synthesis of SiNPs and GO-based nanocomposites for anti-corrosion applications, and to inspire further research in this emerging field. [ABSTRACT FROM AUTHOR]

Background: Denture fracture is a common problem with acrylic dentures. The fractured denture can be repaired using various techniques such as self-cure acrylic resin acrylic resin and fiber-reinforced acrylic resin. Purpose: The purpose of this study was to compare the accuracy of dentures repaired with self-cure acrylic resin and fiber-reinforced acrylic resin processed using two different techniques (long-cure and microwave processing). Materials and methods: A total of 20 maxillary complete dentures were processed with two techniques; heat (long cycle) processing (10 dentures) and microwave processing (10 dentures). The maxillary cast and denture surface were scanned with Medit intraoral (Medit i700, Medit, South Korea) and STL files were created. Then, the dentures were sectioned at the midline and repaired using self-cure acrylic resin and fiber-reinforced acrylic resin and scanned with Medit intraoral. Finally, adaptation deviations were analyzed from computer software (Geomagic Control X, 3D Systems Inc., USA). The adaptation deviations in each group (long cure and microwave) were compared using an Independent T-test. Two-way ANOVA was done to see whether curing techniques and repairing methods affect the accuracy of repair. A P-value of 0.05 was considered significant. Results: The adaptation deviation was slightly higher in the fiber-reinforced acrylic resin group (0.565 ± 0.093) than in the self-cure acrylic resin group (0.536 ± 0.066). However, there was no statistical difference in the adaptation deviations of repaired dentures with self-cure acrylic resin and fiber-reinforced acrylic resin in the long-curing (P-value 0.245) and the microwave (P-value 0.638). Similarly, the adaptation deviation was slightly higher in the long-curing group (0.577 ± 0.075) than in the microwave group (0.524 ± 0.079). However, there was a statistically significant difference in the adaptation deviation of repaired dentures between long-curing and microwave techniques with self-cure acrylic resin (P-value 0.016) but no difference in fiber-reinforced acrylic resin (P-value 0.127). The result of Two-way ANOVA shows that there is no statistically significant interaction between curing techniques (long curing and microwave) and repairing methods (self-cure acrylic resin and fiber-reinforced acrylic resin) for adaptation deviations (P-value 0.646). However, the curing techniques show statistically significant differences (P-value 0.039). Conclusion: Acrylic dentures can be repaired with self-cure resin or fiber-reinforced self-cure resin using various processing methods. The accuracy of the denture after repair is unaffected by the repairing method (self-cure acrylic resin and fiber-reinforced acrylic resin) but the accuracy of the denture after repair is affected by the curing techniques (long-curing and microwave). In self-cure resin, the microwave processing showed higher adaptation deviation and less accuracy, whereas the long-curing processing showed lower adaptation deviation and high accuracy.

This research aimed to assess the effect of immersing heat-cured acrylic resin in tea tree oil solution as a long-term disinfectant. The effect of immersing heat-cured acrylic resin in tea tree oil denture cleanser 180 times on its hardness, UV absorption, water sorption, and solubility was investigated in this study. Ninety heat-cured acrylic resin specimens were prepared and divided into three sets, each consisting of 30 specimens. The specimens were placed in different solutions: distilled water, a solution containing 0.75% tea tree oil, and a solution containing 1% tea tree oil. Each group comprised 10 specimens, and each specimen was submerged for 10 min in accordance with its group. This process was repeated 180 times. After 180 times of immersion, tea tree oil solutions showed non-significant differences (P > 0.05) in surface hardness and statistically significant changes in UV absorption, water sorption, and solubility (P < 0.05). The heat-cured acrylic resin immersed 180 times showed that 0.75% tea tree oil concentration improved solubility and water absorption but not surface hardness and UV absorption. Moreover, 1% tea tree oil concentration enhanced water sorption and solubility. It also decreased UV absorption, but it did not influence hardness. Thus, a 0.75% tea tree oil disinfectant solution is intended to be a long-term denture cleanser.

Abstract Background The present systematic review and meta-analysis investigated the available evidence about the adherence of Candida Albicans to the digitally-fabricated acrylic resins (both milled and 3D-printed) compared to the conventional heat-polymerized acrylic resins. Methods This study followed the guidelines of the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA). A comprehensive search of online databases/search tools (Web of Science, Scopus, PubMed, Ovid, and Google Scholar) was conducted for all relevant studies published up until May 29, 2023. Only in-vitro studies comparing the adherence of Candida albicans to the digital and conventional acrylic resins were included. The quantitative analyses were performed using RevMan v5.3 software. Results Fourteen studies were included, 11 of which were meta-analyzed based on Colony Forming Unit (CFU) and Optical Density (OD) outcome measures. The pooled data revealed significantly lower candida colonization on the milled digitally-fabricated compared to the heat-polymerized conventionally-fabricated acrylic resin materials (MD = − 0.36; 95%CI = − 0.69, − 0.03; P = 0.03 and MD = − 0.04; 95%CI = − 0.06, − 0.01; P = 0.0008; as measured by CFU and OD respectively). However, no differences were found in the adhesion of Candida albicans between the 3D-printed digitally-fabricated compared to the heat-polymerized conventionally-fabricated acrylic resin materials (CFU: P = 0.11, and OD: P = 0.20). Conclusion The available evidence suggests that candida is less likely to adhere to the milled digitally-fabricated acrylic resins compared to the conventional ones.

The low toughness of epoxy resin can influence its shielding performance against a corrosive medium and strength of adhesion to metal surfaces. Extensive efforts have been made to modify epoxy resin. In this research, acrylic resin was synthesized by the solution method, and 1 wt.%, 2.5 wt.%, and 5 wt.% were added to epoxy resin (E44 brand) to prepare coatings on the surface of AZ31B magnesium alloy. The effects of acrylic resin on the mechanical and protective properties of epoxy coatings were investigated via experiments measuring impact resistance, flexibility, and adhesion as well as the electrochemical impedance technique. Compared with the pure epoxy coating, the adhesion between the coating and the substrate increases by 1.37 MPa after the addition of 2.5 wt.% acrylic resin. Meanwhile, the pencil hardness has a slight change from 5B to 6B, and the flexibility significantly improves. Therefore, the epoxy coating exhibits enhanced anticorrosive properties after the addition of 2.5 wt.% acrylic resin. [ABSTRACT FROM AUTHOR]

Objectives. This study was aiming to evaluate the influence of Titanium dioxide nanoparticles addition on the bonding performance of platinum primer (G611) between maxillofacial silicone and acrylic substrate. Materials and methods. 180 samples were divided on two tests (shear and peel bond strength) and they were divided into two main groups (cold cure, and 3D printed) acrylic resins. Each group was subdivided into 5 subgroups (N=9) according to the concentration of nano-filler addition (0%, 0.5%, 1%, 1.5% and 2%) by weight. The data obtained were evaluated by one-way ANOVA and Tukey's post hoc tests at P˂0.05. Results. Statistical analysis revealed (0.5% and 1%) concentrations had significantly the highest bond strength in both groups, whereas (2%) had the lowest bond strength in both groups. Conclusion. Reinforcement of the platinum primer G611 with Titanium dioxide (TiO2) nanoparticles (1%) concentration by weight resulted in a significant improvement in the bonding performance of the platinum primer G611 larger concentrations (1.5%, and 2%) resulted in declining bonding strength. [ABSTRACT FROM AUTHOR]

The general requirement of replacing petroleum-derived plastics with renewable resources is particularly challenging for new technologies such as the additive manufacturing of photocurable resins. In this work, the influence of mono- and bifunctional reactive diluents on the printability and performance of resins based on acrylated epoxidized soybean oil (AESO) was explored. Polyethylene glycol di(meth)acrylates of different molecular weights were selected as diluents based on the viscosity and mechanical properties of their binary mixtures with AESO. Ternary mixtures containing 60% AESO, polyethylene glycol diacrylate (PEGDA) and polyethyleneglycol dimethacrylate (PEG200DMA) further improved the mechanical properties, water resistance and printability of the resin. Specifically, the terpolymer AESO/PEG575/PEG200DMA 60/20/20 (wt.%) improved the modulus (16% increase), tensile strength (63% increase) and %deformation at the break (21% increase), with respect to pure AESO. The enhancement of the printability provided by the reactive diluents was proven by Jacobs working curves and the improved accuracy of printed patterns. The proposed formulation, with a biorenewable carbon content of 67%, can be used as the matrix of innovative resins with unrestricted applicability in the electronics and biomedical fields. However, much effort must be done to increase the array of bio-based raw materials. [ABSTRACT FROM AUTHOR]

Background: The present systematic review and meta-analysis investigated the available evidence about the adherence of Candida Albicans to the digitally-fabricated acrylic resins (both milled and 3D-printed) compared to the conventional heat-polymerized acrylic resins. Methods: This study followed the guidelines of the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA). A comprehensive search of online databases/search tools (Web of Science, Scopus, PubMed, Ovid, and Google Scholar) was conducted for all relevant studies published up until May 29, 2023. Only in-vitro studies comparing the adherence of Candida albicans to the digital and conventional acrylic resins were included. The quantitative analyses were performed using RevMan v5.3 software. Results: Fourteen studies were included, 11 of which were meta-analyzed based on Colony Forming Unit (CFU) and Optical Density (OD) outcome measures. The pooled data revealed significantly lower candida colonization on the milled digitally-fabricated compared to the heat-polymerized conventionally-fabricated acrylic resin materials (MD = − 0.36; 95%CI = − 0.69, − 0.03; P = 0.03 and MD = − 0.04; 95%CI = − 0.06, − 0.01; P = 0.0008; as measured by CFU and OD respectively). However, no differences were found in the adhesion of Candida albicans between the 3D-printed digitally-fabricated compared to the heat-polymerized conventionally-fabricated acrylic resin materials (CFU: P = 0.11, and OD: P = 0.20). Conclusion: The available evidence suggests that candida is less likely to adhere to the milled digitally-fabricated acrylic resins compared to the conventional ones. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim: To determine the effect of immersing heat-cured acrylic resin on tobacco leaf extract (TLE) effervescent tablets 75% on the impact strength. Materials and Methods: This research used an experimental design. Rectangular acrylic resin with a size of 60 mm × 12 mm × 3 mm, according to American Standards for Testing and Materials, was used. The samples were divided into three groups: immersed in distilled water as a negative control group, immersed in a solution of TLE effervescent tablets with a concentration of 75%, and immersed in commercially available dental cleansers as a positive control group. The immersion of the samples was carried out for 16 days which was equivalent to cleaning 30 min per day for 2 years. TLE effervescent tablets were compared with commercially available dental cleansers. Next, the impact strength of the sample was tested. Results: The one-way analysis of variance test results showed a P-value <0.005, that is, a significant difference in each treatment group's impact strength of heat-cured acrylic resin denture bases. The results of the post hoc test (least significance difference; LSD) showed that there is no significant difference in the impact strength of immersed acrylic in 75% TLE effervescent tablets with aquades compared to denture commercially available dental cleansers. Conclusions: 75% TLE effervescent tablets as a denture cleanser have the effect of reducing the impact strength of heat-cured acrylic resin type with a soaking time of 16 days, which is equivalent to cleaning 30 min per day for 2 years. The limitation of this research is the type of heat-cured acrylic used only from one brand, maybe different brands will give different results, so further testing is needed to prove it. [ABSTRACT FROM AUTHOR]

Background: The surface roughness of denture teeth materials significantly influences their clinical performance and patient satisfaction. Understanding the variations in surface roughness among different materials is crucial for optimizing denture fabrication processes. Materials and Methods: In this quantitative in-vitro study, three commonly used denture teeth materials, namely acrylic resin, composite resin, and porcelain, were evaluated for surface roughness. Twenty samples of each material were prepared and subjected to profilometric analysis. The surface roughness parameters Ra and Rz were measured using a contact profilometer. Statistical analysis was performed to compare the surface roughness among the different materials. Results: The mean surface roughness (Ra) values were found to be 0.32 μm for acrylic resin, 0.25 μm for composite resin, and 0.18 μm for porcelain. Similarly, the mean Rz values were 2.45 μm for acrylic resin, 1.98 μm for composite resin, and 1.62 μm for porcelain. Statistical analysis revealed significant differences in surface roughness among the three materials (P < 0.05). Conclusion: Porcelain denture teeth exhibited the smoothest surface, followed by composite resin and acrylic resin. These findings suggest that material selection plays a crucial role in determining the surface roughness of denture teeth. Porcelain may offer superior aesthetics and reduced plaque accumulation compared with acrylic and composite resin materials. Clinicians should consider these differences when choosing denture materials to achieve optimal clinical outcomes and patient satisfaction.

Background: An antimicrobial agent is needed for denture cleaning, such as lemongrass (LG), which has a bioactive antimicrobial component. Methods: This research analyzed LG extract nanoparticles with a particle size analyzer, ZPA, and biofilm formation inhibition on resin acrylic surfaces. Results: We found that there is high stability in nanoparticle size, while other concentrations, including chlorhexidine as a positive control, did not show any statistical differences. Conclusion: Lemongrass oil nanoemulsion has proved to be an antibiofilm and effective as a denture cleaning agent because of its ability to inhibit Streptococcus mutans and Candida albicans growth.

Green cementitious materials are usually developed by the addition of high volumes of mineral fillers. However, the addition of minerals can result in the reduction of mechanical strength. ECCs obtain their superior mechanical behavior from a high volume fraction of fibers. In ECCs, the matrix’s strength and the bond between the fibers and the matrix is a critical parameter, and if it becomes weak, the whole composite becomes weak or fibers may pull out of the matrix. In this study on green ECCs, to increase mechanical strength and also fiber/matrix bonding, the acrylic resin is used in 4 contents (e.g., 0, 2, 4, and 6 % in weight). The tests performed on ECC and plain cement paste (PCP) included tensile, compressive, and flexural. The results show that the acrylic increases the tensile strength, from about 2.0 MPa, up to 20 %, and compressive strength increased from about 88 MPa to 100 MPa. Due to the increase in ductility, the energy-based indexes increase more significantly. Acrylic resin optimum content was measured as 1.5–2.7 % (by weight). The trends show that acrylic resin is more effective for ECCs, because, in addition to enhancing the matrix strength, the resin increases the bonding strength between the matrix and fiber. Seeking the relationship between the results, nonlinear regression was used, and governing equations were presented. Also, using a regression model, the mechanical parameters were predicted successfully using input parameters.

This study aimed to incorporate β-AgVO3 and rGO into self-curing (SC) and heat-curing (HC) acrylic resins and to evaluate their physicochemical, mechanical, and antimicrobial properties while correlating them with the characterized material structure. Acrylic resin samples were prepared at 0 % (control), 0.5 %, 1 %, and 3 % for both nanoparticles. The microstructural characterization was assessed by scanning electron microscopy (SEM) (n = 1) and energy dispersive X-ray spectroscopy (EDS) (n = 1). The physicochemical and mechanical tests included flexural strength (n = 10), Knoop hardness (n = 10), roughness (n = 10), wettability (n = 10), sorption (n = 10), solubility (n = 10), porosity (n = 10), and color evaluation (n = 10). The microbiological evaluation was performed by counting colony-forming units (CFU/mL) and cell viability (n = 8). The results showed that the β-AgVO3 samples showed lower counts of Candida albicans, Pseudomonas aeruginosa, and Streptococcus mutans due to their promising physicochemical properties. The mechanical properties were maintained with the addition of β-AgVO3. The rGO samples showed higher counts of microorganisms due to the increase in physicochemical properties. It can be concluded that the incorporation of β-AgVO3 into acrylic resins could be an alternative to improve the antimicrobial efficacy and performance of the material.

Background: Surface roughness and hardness are key factors that influence the clinical performance and durability of denture teeth. Understanding variations in these properties among different denture teeth materials can assist in selecting the most suitable materials for optimal patient outcomes. This study aimed to investigate the surface roughness and hardness of four commonly used denture teeth materials: acrylic resin, composite resin, porcelain, and nanohybrid composite. Materials and Methods: Ten specimens were prepared for each denture teeth material, resulting in a total of 40 specimens. Surface roughness was assessed using a profilometer, and measurements were recorded in micrometers (μm). Hardness was determined using a Vickers hardness tester, and results were expressed as Vickers hardness numbers (VHN). The surface roughness and hardness data were analyzed using appropriate statistical tests (e.g., analysis of variance), with significance set at P < 0.05. Results: The results revealed significant differences in both surface roughness and hardness among the different denture teeth materials (P < 0.05). Acrylic resin exhibited the highest surface roughness (mean ± standard deviation: 3.45 ± 0.78 μm) and the lowest hardness (mean ± standard deviation: 45.6 ± 2.3 VHN). Composite resin demonstrated intermediate values of surface roughness (mean ± standard deviation: 1.87 ± 0.54 μm) and hardness (mean ± standard deviation: 65.2 ± 3.9 VHN). Porcelain demonstrated the smoothest surface (mean ± standard deviation: 0.94 ± 0.28 μm) and the highest hardness (mean ± standard deviation: 78.5 ± 4.1 VHN). Nanohybrid composite displayed surface roughness and hardness values similar to composite resin. Conclusion: This study demonstrated significant variations in surface roughness and hardness among the different denture teeth materials evaluated. Acrylic resin exhibited the roughest surface and lowest hardness, while porcelain demonstrated the smoothest surface and highest hardness. Composite resin and nanohybrid composite exhibited intermediate values. These findings provide valuable insights for prosthodontic practitioners in selecting denture teeth materials based on specific clinical requirements, aiming to achieve optimal aesthetics, reduced plaque accumulation, and improved wear resistance.

Background and Purpose: This study aimed to evaluate the flexural strength, color change and antimicrobial effect of silver–zeolite nanoparticles (NPs) in acrylic resin materials. Methods: Fifty-six disc-shaped acrylic resin samples were divided into four groups (n = 7) according to concentrations of silver–zeolite NPs (0%, 2%, 4%, 5%). Discs were contaminated with C. albicans and S. mutans. The antimicrobial effect was tested by inoculating contaminated discs on Tryptic soy agar (TSA), Sabouraud Dextrose Agar (SDA), Tryptic soy broth (TSB), and Sabouraud dextrose broth (SDB). Forty rectangular 65 × 10 × 2.5 mm acrylic resin specimens were also classified into four groups (n = 10) according to concentrations of silver–zeolite NPs. For the color change, L, a, and b values of rectangular specimens were examined with a spectrophotometer. A three-point bending test was also performed using a Devotrans device to determine the flexural bond strength of rectangular specimens. Scanning electron microscope analysis (SEM/EDX analysis) was also performed. Results: In this study, the antimicrobial effect increased with the concentration of silver–zeolite NPs added to acrylic resin discs. In our study, adding 2% silver–zeolite NPs was more effective against C. albicans. The antimicrobial effect against S. mutans increased with concentration of silver–zeolite NPs (C. albicans was significantly reduced by silver–zeolite NPs. A significant increase was observed in the color change as the nanoparticle percentage ratio increased (p < 0.001). The flexural strength values of the groups containing 2% and 4% nanoparticles were found to be clinically acceptable. Conclusions: The study showed that bacterial and fungal colonization is significantly reduced by adding silver–zeolite nanoparticles to acrylic resin discs. Based on its antimicrobial, physical, and mechanical properties, we recommend adding 2% silver–zeolite nanoparticles to the acrylic resin material for optimal results.

The main goal of this work was an improvement in the mechanical and electrical properties of acrylic resin-based nanocomposites filled with chemically modified carbon nanotubes. For this purpose, the surface functionalization of multi-walled carbon nanotubes (MWCNTs) was carried out by means of aryl groups grafting via the diazotization reaction with selected aniline derivatives, and then nanocomposites based on ELIUM® resin were fabricated. FT-IR analysis confirmed the effectiveness of the carried-out chemical surface modification of MWCNTs as new bands on FT-IR spectra appeared in the measurements. TEM observations showed that carbon nanotube fragmentation did not occur during the modifications. According to the results from Raman spectroscopy, the least defective carbon nanotube structure was obtained for aniline modification. Transmission light microscopy analysis showed that the neat MWCNTs agglomerate strongly, while the proposed modifications improved their dispersion significantly. Viscosity tests confirmed, that as the nanofiller concentration increases, the viscosity of the mixture increases. The mixture with the highest dispersion of nanoparticles exhibited the most viscous behaviour. Finally, an enhancement in impact resistance and electrical conductivity was obtained for nanocomposites containing modified MWCNTs. [ABSTRACT FROM AUTHOR]

Background: Surface roughness and hardness are key factors that influence the clinical performance and durability of denture teeth. Understanding variations in these properties among different denture teeth materials can assist in selecting the most suitable materials for optimal patient outcomes. This study aimed to investigate the surface roughness and hardness of four commonly used denture teeth materials: acrylic resin, composite resin, porcelain, and nanohybrid composite. Materials and Methods: Ten specimens were prepared for each denture teeth material, resulting in a total of 40 specimens. Surface roughness was assessed using a profilometer, and measurements were recorded in micrometers (μm). Hardness was determined using a Vickers hardness tester, and results were expressed as Vickers hardness numbers (VHN). The surface roughness and hardness data were analyzed using appropriate statistical tests (e.g., analysis of variance), with significance set at P < 0.05. Results: The results revealed significant differences in both surface roughness and hardness among the different denture teeth materials (P < 0.05). Acrylic resin exhibited the highest surface roughness (mean ± standard deviation: 3.45 ± 0.78 μm) and the lowest hardness (mean ± standard deviation: 45.6 ± 2.3 VHN). Composite resin demonstrated intermediate values of surface roughness (mean ± standard deviation: 1.87 ± 0.54 μm) and hardness (mean ± standard deviation: 65.2 ± 3.9 VHN). Porcelain demonstrated the smoothest surface (mean ± standard deviation: 0.94 ± 0.28 μm) and the highest hardness (mean ± standard deviation: 78.5 ± 4.1 VHN). Nanohybrid composite displayed surface roughness and hardness values similar to composite resin. Conclusion: This study demonstrated significant variations in surface roughness and hardness among the different denture teeth materials evaluated. Acrylic resin exhibited the roughest surface and lowest hardness, while porcelain demonstrated the smoothest surface and highest hardness. Composite resin and nanohybrid composite exhibited intermediate values. These findings provide valuable insights for prosthodontic practitioners in selecting denture teeth materials based on specific clinical requirements, aiming to achieve optimal aesthetics, reduced plaque accumulation, and improved wear resistance. [ABSTRACT FROM AUTHOR]

In recent years, the use of low viscosity and in‐situ polymerizable thermoplastic acrylic resins for advanced fiber reinforced composites has grown, specially to address the difficulty of fiber impregnation with high‐melt viscosity thermoplastic polymers. The present work investigated the curing kinetics, chemo‐rheology of an acrylic resin system for in‐situ pultrusion, and proposed the corresponding constitutive models. First, the curing kinetics was studied with the differential scanning calorimetry experiments. The viscosity development was obtained by a rheometer as functions of the degree of cure (DOC) and temperatures. The gelation point was acquired from the intersection point of storage and loss modulus curves through dynamic mechanical analysis test, which occurs at DOC of 0.65 determined by the cure kinetics model. Through the dynamic mechanical analysis, a four step cure hardening modulus model (modified CHILE approach) was proposed. The aforementioned models were applied in a case study to evaluate the influence of process parameters on the DOC, viscosity and physical behavior of the acrylic resin system in the pultrusion die. Highlights: Material characterizations of an acrylic resin system are investigated.The cure kinetics and viscosity and elastic modulus models are proposed.A pultrusion case study is given. [ABSTRACT FROM AUTHOR]

3D-printing has gained popularity in recent years due to the many advantages it offers over the traditional approaches for instance this technology reduces the time a dentist needs to create and fit dentures to just 2–3 sessions. Fumaric, maleic, and adipic acids with the percentage (0.1 wt.%) were added to chitosan solution (2 wt.%) and the final composite was added to the 3D printable acrylic resin. The specimens were examined for several chemical analyses (XRD, SEM, FTIR) and mechanical tests (impact strength and surface hardness tests), where the total number (115) of specimens used in the study was specimens divided into five groups. In chemical analysis, one specimen was constructed for each modified group and one specimen was used as the control group (3d printable resin without addition (non-modified) for each test. For mechanical tests ten specimens were constructed for each modified group and ten specimens were used as the control group (3d printable resin without addition (non-modified) for each test. The results of chemical analysis showed improvement in the properties of modified 3d printable acrylic denture base resin, additionally the mechanical test results showed that the (Fumaric acid and Maliec acid with Chitosan) specimens have the highest properties in comparison with other specimens, while the lowest properties were for specimens of 3D printable acrylic resin with chitosan. The chemical and mechanical properties of the modified 3D-printed denture base are improved when chitosan is modified with dicarboxylic acids. Conversely, if chitosan alone is used to modify the 3D-printed polymers, the mechanical and chemical properties would be decreased. [ABSTRACT FROM AUTHOR]

Background. Nowadays, acrylic dentures are commonly used in the treatment of various clinical situations. The preoccupations in improving physical and biological properties are therefore mandatory. Aims. The aim of this study was to assess the most common causes that lead to fractures in different areas of both, mandibular and maxillary dentures, considering the materials, the polymerization techniques but also the possibility of enhancing the fracture resistance. Methods. Literature research among the latest articles published on this topic was performed using related keywords. Results. Several issues involved in denture fractures can be related to the dentist, technician, and patient. Conclusions. The proper analysis and consideration of the causes, treatment steps and recommendations can reduce the risk of denture fractures. [ABSTRACT FROM AUTHOR]

Discoloration can be the problem of provisional restorations, especially in long-term treatment cases. The surface coating materials may influence the properties of provisional restorative material. This study aimed to evaluate the effect of silane-SiO2 film coating on the color stability and surface roughness of provisional fixed prosthodontic material compared to three commercial surface coating agents. A total of 160 specimens were fabricated from auto-polymerized polymethyl methacrylate resin (PMMA: Unifast Trad) and divided randomly into five groups according to applied surface coating procedures: non-coated (control) and four surface coated (silane-SiO2, Palaseal, Biscover LV, Optiglaze). Surface roughness (Ra) values were assessed by a profilometer. One specimen for each group, surface morphology was analyzed by SEM examination and element composition was analyzed by energy dispersive spectroscopy (EDS) before and after immersion in distilled water for 30 days. Color changes (ΔE) were measured as CIE L*a*b* value with a spectrophotometer before immersion and 1 day, 7 days, and 30 days after immersion in solutions (distilled water, tea, coffee). The data were statistically analyzed using repeated measure ANOVA on the color stability test and one-way ANOVA on the surface roughness with Bonferroni adjustment for multiple comparisons (a=.05). The mean Ra value of all groups ranged from 0.201 to 0.264. No significant differences were found among groups on surface roughness result(P>.05). Silane-SiO2 coated PMMA acrylic resin presented the lowest ΔE value in all conditions. Palaseal group showed the highest color change in the coffee solution and Biscover LV coated showed the highest color alteration in distilled water and tea solution. The different surface coatings showed significant color changes in acrylic resin (P<.05). Silane-SiO2 film-coated acrylic resin showed the most color stability compared to commercial surface coating agents and conventional polishing methods, only silane-SiO2 and Optiglaze coated groups presented a clinically acceptable color change (ΔE<3.7) in all solutions over the period of immersion. Silane-SiO2 coated groups showed the lowest Ra value but not statistically significant difference from other groups. [ABSTRACT FROM AUTHOR]

Purpose This study aimed to evaluate the effect of nylon versus heat‑cure acrylic resin on microbial adhesion of a closed hollowed obturator. Patients and methods Twelve male patients with a unilaterally acquired maxillary defect (Aramany Class IV) were chosen from the outpatient clinic of the Prosthodontics Department at the Faculty of Dentistry, Sinai University (Kantara branch). These patients were divided into two equal groups: group I was provided with an obturator made of heat‑cured acrylic resin (P.M.M.A.‑Vertex), while group II received an obturator made of thermopress resin (nylon breflex, 2nd edition). Each group underwent microbial evaluation through follow‑up recall visits at 2 and 4 weeks. The results were recorded, tabulated, and subjected to statistical analysis. Results There is a significant difference between group I and group II. The conventional acrylic resin group showed higher bacterial adhesion than the nylon. Conclusion Within the limitations of the study, a closed hollow bulb constructed with thermopress resin exhibits reduced bacterial colonization when compared to heat‑cured acrylic resin. [ABSTRACT FROM AUTHOR]

A person’s face being a visible element, instant physical care and mental support is mandatory for patients affected with maxillofacial defects. Defects in noticeable locations like the ear create a lacuna which deteriorates the quality of life of the victims. Immediate restoration of the defect with artificial prosthesis becomes crucial. Two such cases of acquired auricular defects rehabilitated with maxillofacial prosthesis are described in this manuscript. This case report briefs about two patients with auricular defects reported for restoration. Case one had a congenital agenesis of his right ear whereas case two presented with a history of trauma. Immediate management with artificial ear prosthesis was decided to restore the patients to normalcy of life. Hence an effective restoration was carried out using maxillofacial auricular prosthesis made from medical grade silicone and acrylic. They were retained onto to the residual external structures. [ABSTRACT FROM AUTHOR]

In this study, MIL‐101 (Cr) and NH2‐MIL‐101 (Cr) nanoparticles were synthesized by hydrothermal method. Butyl acrylate‐styrene copolymer was used along with these nanoparticles to improve the mechanical properties of epoxy adhesive. The results of the Fourier Transform Infrared (FTIR) and X‐ray diffraction (XRD) test showed that the synthesis and functionalization of the metal organic framework (MOFs) were successful. The mechanical properties and adhesion features in the lap joint bonding of aluminum foil to the aluminum foil of modified epoxy adhesives were investigated by tensile and lap shear tests. The results of the tensile test showed that by adding 0.3 wt% of NH2‐MIL‐101 (Cr) and 2.5 wt% of poly(butyl acrylate‐block‐styrene) to epoxy adhesive, the tensile strength, modulus and toughness of dumbbell samples were increased up to 34.46%, 31.74% and 58.53%, respectively. Furthermore, based on the lap shear test results, by adding 0.3 wt% NH2‐MIL‐101 (Cr) along with 2.5% poly(butyl acrylate‐block‐styrene) to the epoxy adhesive, the lap shear strength of samples increased from 1.05 ± 0.08 MPa to 5.25 ± 0.06 MPa compared to the neat epoxy adhesive. According to the TGA test, the highest thermal stability is related to the sample containing 0.3 wt% of NH2‐MIL‐101 nanoparticles and 2.5 wt% of the copolymer. The image of the fracture surface of the sample containing 0.3 wt%. NH2‐MIL‐101 (Cr) and 2.5 wt% block copolymer shows that the interface of nanoparticles and the matrix improved due to the chemical reaction of functional groups of nanoparticles and adhesive matrix. [ABSTRACT FROM AUTHOR]

The colonisation of the surface of removable acrylic dentures by various types of microorganisms can lead to the development of various diseases. Therefore, the creation of a bioactive material is highly desirable. This study aimed to develop a denture base material designed to release bioactive ions into the oral environment during use. Four types of bioactive glasses (BAG)—S53P4, Biomin F, 45S5, and Biomin C—were incorporated into the PMMA acrylic resin, with each type constituting 20 wt.% (10 wt.% non-silanised and 10% silanised) of the mixture, while PMMA acrylic resin served as the control group. The specimens were subsequently immersed in distilled water, and pH measurements of the aqueous solutions were taken every seven days for a total of 38 days. Additionally, surface roughness and translucency measurements were recorded both after preparation and following seven days of immersion in distilled water. The cytotoxicity of these materials on human fibroblast cells was evaluated after 24 and 48 h using Direct Contact and MTT assays. Ultimately, the elemental composition of the specimens was determined through energy-dispersive X-ray (EDX) spectroscopy. In general, the pH levels of water solutions containing BAG-containing acrylics gradually increased over the storage period, reaching peak values after 10 days. Notably, S53P4 glass exhibited the most significant increase, with pH levels rising from 5.5 to 7.54. Surface roughness exhibited minimal changes upon immersion in distilled water, while a slight decrease in material translucency was observed, except for Biomin C. However, significant differences in surface roughness and translucency were observed among some of the BAG-embedded specimens under both dry and wet conditions. The composition of elements declared by the glass manufacturer was confirmed by EDX analysis. Importantly, cytotoxicity analysis revealed that specimens containing BAGs, when released into the environment, did not adversely affect the growth of human gingival fibroblast cells after 48 h of exposure. This suggests that PMMA acrylics fabricated with BAGs have the potential to release ions into the environment and can be considered biocompatible materials. Further clinical trials are warranted to explore the practical applications of these materials as denture base materials. [ABSTRACT FROM AUTHOR]

This experiment was conducted to formulate a water‐based ink with antimicrobial properties for packaging applications. Two distinct types of inks were developed, one with synthetic yellow color pigment and the other with curcumin, as an antimicrobial and a natural yellow pigment. The resulting two inks were then printed on polyethylene terephthalate (PET) films, and the physiochemical characteristics of the ink were thoroughly examined. The coated inks had an average thickness of 10 microns for both the inks. The viscosity of the water‐based ink and the antimicrobial water‐based ink were determined to be 54cp and 30cp, respectively and the drying time of the inks was 10 sec. At the same time, the gloss value increased from 30% to 50% in the case of antimicrobial ink. The antimicrobial efficacy of the antimicrobial water‐based ink, as demonstrated against S. aureus and E. coli, surpassed that of the conventional water‐based ink. These findings showed that the antimicrobial water‐based ink had a good drying time, increased gloss, and favorable storage stability. Using curcumin as a pigment in water‐based ink may be significant for printing applications of active food packaging materials. It can also help lower the risk of contamination of the food components with microbes. Highlights: Synthesis of antimicrobial water‐based inkActive packaging printingCurcumin as an antimicrobialCurcumin used as a natural color pigment in the inkAcrylic resin synthesis [ABSTRACT FROM AUTHOR]

Copyright of Journal of Dalian Polytechnic University is the property of Journal of Dalian Polytechnic University Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of GeSec: Revista de Gestao e Secretariado is the property of Sindicato das Secretarias e Secretarios do Estado de Sao Paulo (SINSESP) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To assess the influence of dentifrices with different abrasiveness levels on the properties of dental reconstructive materials. Forty-eight cylinders were obtained from four polymeric materials, being two CAD/CAM acrylic resins (Ivotion-Dent and Ivotion-Base), one injected acrylic resin (IvoBase-Hydrid) and one light-cured resin composite (Empress Direct). Specimens were allocated to four subgroups for toothbrushing simulation according to the dentifrice relative dentin abrasivity (RDA) and silica content: (i) RDA 0 = 0%; (ii) RDA 50 = 3%; (iii) RDA 100 = 10%; and (iv) RDA 120 = 25%. Specimens were then subjected to toothbrushing. Surface analyses [surface roughness Ra (SR) and scanning electron microscopy (SEM)] along with hardness and optical properties [translucency parameter (TP) and contrast ratio (CR)] were evaluated before and after toothbrushing. Statistical analyses were performed using ANOVA and Tukey test. A significant increase in SR was observed after toothbrushing with higher RDA toothpastes for Ivotion-Dent (100 and 120) and IvoBase-Hybrid (120). Ivotion-Base and Empress Direct presented no significant differences in SR when analyzed as a function of timepoint and RDA levels. Hardness was not influenced by toothbrushing with different RDA dentifrices, except for Empress Direct with RDA 0 toothpaste, where a decrease in the hardness was observed. TP of Ivotion-Dent and Empress Direct significantly decreased after toothbrushing with higher RDA dentifrices and CR of Ivotion-Dent, Empress Direct and IvoBase-Hybrid significantly increased with higher RDA dentifrices. The levels of dentifrice abrasiveness affected differently the SR, hardness and optical properties of polymeric reconstructive materials after toothbrushing. [ABSTRACT FROM AUTHOR]

In this research, a new eco-friendly collagen polypeptide-based foaming agent (CPFC) was prepared via a hydrophobic grafting modification of the collagen polypeptide (CP) from oily acrylic resin, in which the CP was extracted from leather wastes. The molecular structure of CPFC was characterized by FTIR, TGA, XRD, and laser particle size tests. The results showed that the oily acrylic acid molecular chain segments effectively copolymerized with CP, improving the hydrophilic and lipophilic balance of CP molecules. Given the increase of acrylic resin content in CPFC, the surface tension of CPFC at the critical micelle concentration gradually decreased and tended toward the critical value (30 mN/m). The foamability and foaming multiple of 9-CPFC and 7-CPFC reached 535 mL and 31.89 times, respectively. Next, we prepared a CPFC-based foam concrete with a dry density of 500 Kg/m3 via compounding a mechanical CPFC foaming agent with concrete. The resulting CPFC-based foam concrete was then characterized using a universal testing machine, thermal conductivity meter, ultra-depth 3d microscope, and other analysis techniques. The results indicated that the 5-CPFC foam concrete possessed good foam stability and compatibility. Moreover, the pore size distribution of the foam concrete was uniform, showing a less stringy pore structure, and the water absorption rate and thermal conductivity levels were 27.8 % and 0.61 W/m·K, respectively. The compressive strength of cement was approximately 1.37 MPa, which exceeds the national standard. Moreover, it was found that the CPFC possessed certain retarding properties that were similar to cement, suggesting that it is a highly suitable additive for foam concrete.

Background: Recent advancements in three-dimensional (3D) printing have introduced novel materials for removable partial dentures (RPD) base fabrication, promising improved mechanical properties, and biocompatibility. Materials and Methods: In this study, three different RPD base materials were evaluated: conventional heat-cured acrylic resin (Control), biocompatible 3D-printed resin (Test Group A), and a novel nanocomposite 3D-printed resin (Test Group B). A total of 30 standardized RPD base specimens (n = 10 per group) were fabricated according to established protocols. Microstructural analysis was performed using scanning electron microscopy (SEM), and the mechanical properties, including flexural strength and modulus, were determined using a universal testing machine. Results: Microstructural analysis revealed distinct differences among the materials. SEM images showed a well-defined and homogeneous microstructure in Test Group B, while Test Group A exhibited fewer voids compared to the Control group. Mechanical testing results indicated that Test Group B had the highest flexural strength (120 ± 5 MPa), followed by Test Group A (90 ± 4 MPa), and the Control group (75 ± 3 MPa). Similarly, Test Group B demonstrated the highest flexural modulus (3.5 ± 0.2 GPa), followed by Test Group A (2.8 ± 0.1 GPa), and the Control group (2.1 ± 0.1 GPa). Conclusion: These findings suggest that 3D-printed RPD base materials, particularly nanocomposite resins, hold promise for improving the overall quality and durability of removable partial dentures.

Abstract Background This study aimed to determine the relative positioning accuracy of multiple implants utilizing four distinct types of splinting materials. Methods The purpose of this in-vitro study was to compare the precision of four splinting materials in an open tray impression technique in multiple implant situations. Based on the material used for splinting, four groups were made (n = 40)- Group A: Conventional Method, Group B: Prefabricated Pattern Resin Framework, Group C: Prefabricated Metal Framework, Group D: Light Cured Pattern Resin, these groups were compared with the master model. A heat-cured clear acrylic resin and a master model were constructed. A pilot milling machine drill was used to drill four parallel holes in the anterior and premolar regions, which were later labeled as A, B, C, and D positions from right to left. Then, sequential drilling was carried out, and four 3.75‑mm diameter and 13-mm long ADIN implant analogs with internal hex were placed in the acrylic model using a surveyor for proper orientation. The impression posts were then manually screwed to the implant analogs using an open tray, and they were secured to the implants using 10 mm flat head guide pins with a 15 N.cm torque. 10 Open tray polyether impressions were made, and casts were poured. Each splinting method’s distortion values were measured using a coordinate measuring machine capable of recordings in the X-, Y-, and Z-axes. Comparison of mean distances for X1, X2, and X3 was made using the Kruskal-Wallis test, and Pairwise comparison was done using Post Hoc Tukey’s Test. Results The differences between the groups were significant when assessing the distances X1, X2, and X3 (p 0.05). Conclusions All splinting materials produced master casts with measurements in close proximity to the reference model. However, prefabricated pattern resin bars splinting showed the highest accuracy among the studied techniques. The most recent splinting techniques using prefabricated metal framework and light-cure pattern resin showed similar accuracy.