Search

Biopolymers such as chitosan and pectin are currently attracting significant attention because of their unique properties, which are valuable in the food industry and pharmaceutical applications. These properties include non-toxicity, compatibility with biological systems, natural decomposition ability, and structural adaptability. The objective of this study was to assess the performance of two different ratios of pectin-chitosan polyelectrolyte composite (PCPC) after applying them as a coating to commercially pure titanium (CpTi) substrates using electrospraying. The PCPC was studied in ratios of 1:2 and 1:3, while the control group consisted of CpTi substrates without any coating. The pull-off adhesion strength, cytotoxicity, and antibacterial susceptibility tests were utilized to evaluate the PCPC coatings. In order to determine whether the composite coating was the result of physical blending or chemical bonding, the topographic surface parameters were studied using Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). PCPC (1:3) had the highest average cell viability of 93.42, 89.88, and 86.85% after 24, 48, and 72 h, respectively, as determined by the cytotoxicity assay, when compared to the other groups. According to the Kirby-Bauer disk diffusion method for testing antibacterial susceptibility, PCPC (1:3) showed the highest average diameter of the zone of inhibition, measuring 14.88, 14.43, and 11.03 mm after 24, 48, and 72 h of incubation, respectively. This difference was highly significant compared to Group 3 at all three time periods. PCPC (1:3) exhibited a significantly higher mean pull-off adhesion strength (521.6 psi) compared to PCPC (1:2), which revealed 419.5 psi. PCPC (1:3) coated substrates exhibited better surface roughness parameters compared to other groups based on the findings of the AFM. The FTIR measurement indicated that both PCPC groups exhibited a purely physical blending in the composite coating. Based on the extent of these successful in vitro experiments, PCPC (1:3) demonstrates its potential as an effective coating layer. Therefore, the findings of this study pave the way for using newly developed PCPC after electrospraying coating on CpTi for dental implants., (© 2024. The Author(s).)

As a unique natural resource, fungi are a sustainable source of lipids, polysaccharides, vitamins, proteins, and other nutrients. As a result, they have beneficial medicinal and nutritional properties. Polysaccharides are among the most significant bioactive components found in fungi. Increasing research has revealed that fungal polysaccharides (FPS) contain a variety of bioactivities, including antitumor, antioxidant, immunomodulatory, anti-inflammatory, hepatoprotective, cardioprotective, and anti-aging properties. However, the exact knowledge about FPS and their applications related to their future possibilities must be thoroughly examined to enhance a better understanding of this sustainable biopolymer source. Therefore, FPS' biological applications and their role in the food and feed industry, agriculture, and cosmetics applications were all discussed in this work. In addition, this review highlighted the mode of action of FPS on human diseases by regulating gut microbiota and discussed the mechanism of FPS as antioxidants in the living cell. The structure-activity connections of FPS were also highlighted and explored. Moreover, future perspectives were listed to pave the way for future studies of FPS applications. Hence, this study can be a scientific foundation for future FPS research and industrial applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Pectin and chitosan are natural polysaccharides obtained from fruit peels and exoskeletons of crustaceans and insects. They are safe for usage in food products and are renewable and biocompatible. They have further applications as wound dressings, body fat reduction, tissue engineering, and auxiliary agents in drug delivery systems. The healing process is usually long and painful. Adding a new material such as a pectin-chitosan composite to the implant surface or body would create unique biological responses to accelerate healing and delivery of target-specific medication at the implant site. The present study utilized the electrospraying process to create pectin-chitosan polyelectrolyte composite (PCPC) coatings with various ratios of 1:1, 2:1, 1:2, 1:3, and 3:1 on commercially pure titanium substrates. By means of FESEM, AFM, wettability, cross-cut adhesion, and microhardness were assessed the PCPC coatings' physical and mechanical properties. Subsequently, the antibacterial properties of the coating composite were assessed. AFM analysis revealed higher surface roughness for group 5 and homogenous coating for group 1. Group 3 showed the lowest water contact angle of 66.7° and all PCPC coatings had significantly higher Vickers hardness values compared to the control uncoated CpTi samples. Groups 3 and 4 showed the best adhesion of the PCPC to the titanium substrates. Groups 3, 4, and 5 showed antibacterial properties with a high zone of inhibitions compared to the control. The PCPC coating's characteristics can be significantly impacted by using certain pectin-chitosan ratios. Groups 3 (1:2) and 4 (1:3) showed remarkable morphological and mechanical properties with better surface roughness, greater surface strength, improved hydrophilicity, improved adhesion to the substrate surface, and additionally demonstrated significant antibacterial properties. According to the accomplished in vitro study outcomes, these particular PCPC ratios can be considered as an efficient coating for titanium dental implants., (© 2023. The Author(s).)

The process of repairing the fractured nylon denture bases and addition of acrylic teeth to the previously worn nylon denture bases has not been widely studied. This study aims to assess the transverse strength of nylon denture bases repaired by various resin materials, different curing techniques, and types of surface treatments. Materials and Methods . One hundred fifty thermoplastic nylon denture base samples were fabricated using plastic patterns measuring 65 × 10 × 2.5 mm (length, width, and thickness, respectively). These samples were then divided into three equal groups. Fifty samples were repaired by microwave heat-polymerization, fifty samples were repaired using the Ivomate autopolymerization, and the other fifty were repaired using light-polymerized acrylic resin. Each of these three groups was further divided into five subgroups of ten samples based on the type of surface treatment. The samples in the control group did not undergo any surface treatment, and the other four groups were chemically surface treated with monomer, acetone, ethyl acetate, and isopropanol, respectively. A three-point bending test was used to calculate the transverse strength values of the samples. Fourier transform infrared (FTIR) analysis was conducted to determine the component of functional groups between the polyamide nylon base and poly(methyl-methacrylate) PMMA repair materials. A polarizing microscope was utilized to investigate the mode of failure at the fracture surfaces. Results . The collected data were analyzed with one-way ANOVA and Sidak's multiple comparison test to show the differences among different groups. For surface treatments, the highest transverse strength values were obtained by monomer-treated samples (18.29 N/mm 2 ); however, the lowest values were obtained in non-surface treated samples (5.58 N/mm 2 ). While for repair techniques, the highest transverse strength values were obtained by microwave processing, followed by Ivomate and then the light-cured polymerization. The means were found to be significant ( p < 0.001). FTIR analysis shows the presence of hydrogen bonding which is due to the ester and amid groups which enhance the bond strength of the surface-treated samples. The interface of the polarizing microscope images revealed a cohesive fracture within repair materials rather than the adhesive nature. Conclusion . The microwave-polymerized resin was considered as the most effective repair technique along with monomer chemical etchant which creates a tight adhesion between PMMA and nylon denture base in comparison to other groups., Competing Interests: The authors have no conflicts of interest relevant to this article., (Copyright © 2020 Ghassan Abdul-Hamid Naji.)

The nanotechnology field plays an important role in the improvement of dental implant surfaces. However, the different techniques used to coat these implants with nanostructured materials can differently affect cells, biomolecules and even ions at the nano scale level. The aim of this study is to evaluate and compare the structural, biomechanical and histological characterization of nano titania films produced by either modified laser or dip coating techniques on commercially pure titanium implant fixtures. Grade II commercially pure titanium rectangular samples measuring 35 × 12 × 0.25 mm length, width and thickness, respectively were coated with titania films using a modified laser deposition technique as the experimental group, while the control group was dip-coated with titania film. The crystallinity, surface roughness, histological feature, microstructures and removal torque values were investigated and compared between the groups. Compared with dip coating technique, the modified laser technique provided a higher quality thin coating film, with improved surface roughness values. For in vivo examinations, forty coated screw-designed dental implants were inserted into the tibia of 20 white New Zealand rabbits' bone. Biomechanical and histological evaluations were performed after 2 and 4 weeks of implantation. The histological findings showed a variation in the bone response around coated implants done with different coating techniques and different healing intervals. Modified laser-coated samples revealed a significant improvement in structure, surface roughness values, bone integration and bond strength at the bone-implant interface than dip-coated samples. Thus, this technique can be an alternative for coating titanium dental implants.

In all-ceramic systems, a high incidence of veneer chip-off has been reported in clinical studies. Coefficient of thermal expansion (CTE) behaviour is one of the factors that may increase residual stress in the interface and influence the veneer/core bond strength. Therefore, this study aimed to evaluate the effect of sodalite zeolite-infiltration on the CTE behaviour and bond strength of different all-ceramic prostheses. The case-study groups were synthesized sodalite zeolite-infiltrated alumina (IA-SOD) and synthesized sodalite zeolite-infiltrated zirconia-toughened alumina (ZTA) (IZ-SOD), while the control groups were glass-infiltrated alumina (IA-glass) and glass-infiltrated ZTA (IZ-glass). Forty cylindrical-shaped samples measuring 5 mm in diameter and 10 mm in height were tested for CTE using a thermo-mechanical analyser machine, and forty disc-shaped ceramic samples measuring 12 mm in diameter and 1.2 ± 0.2 mm in thickness were prepared using specially designed stainless steel split mould and veneered by cylinder-shaped (2 mm high × 2 mm diameter) low-fusing porcelain (Vita VM7). The veneer/core samples were sintered and tested for shear bond strength using a high precision universal testing machine. Scanning electron microscope, stereo microscope, atomic force microscope, and energy-dispersive X-ray spectroscopy were used to investigate the structural characteristics of samples at the fracture surface. The collected data were analyzed with a one-way ANOVA and Tukey HSD test (α=.05). IZ-SOD revealed highest CTE and shear bond strength values, while the IA-glass revealed the lowest values than the other groups. There was no significant difference in CTE and bond strength among IZ-SOD, IA-SOD and IZ-glass samples (p>0.05). The experimental SOD zeolite-infiltrated samples revealed higher CTE mismatch and bond strength along with a more favourable mode of failure than did the commercial glass-infiltrated samples. Sandblast technique is considered as effective conditioning procedure for enhancing the surface roughness of SOD zeolite-infiltrated frameworks which subsequently improving the bond strength., (Copyright © 2016 Elsevier Ltd. All rights reserved.)