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Abstract Leishmaniasis is a tropical disease caused by Leishmania parasites and currently has no licensed vaccines. We developed a dermotropic Leishmania major centrin gene-deleted strain (LmCen –/–) as a live attenuated vaccine. Recent studies have shown that type I interferons (IFNs) play important roles in immunity to parasitic and viral pathogens. However, their relevance in protective immunity following vaccination is not understood. We found that immunization with LmCen –/– induces a transient increase in type I IFN response along with its regulatory factor IRF7 that is downregulated 7–21 days post-immunization, coincided with the induction of a robust Th1 adaptive immune response. Challenge infection with virulent L. donovani parasites showed a significant reduction of splenic and hepatic parasite burden in IRF7–/– mice than wild type mice following immunization with LmCen –/– , suggesting that ablation of type I IFN response is a pre-requisite for the induction of LmCen –/– mediated Th1 immunity against L. donovani infection.

Background: This study aimed to evaluate the effect of new computer-aided design/computer-aided manufacturing all-ceramic materials on the viability and adhesion properties of human gingival fibroblasts (HGFs). Materials and Methods: In this experimental study, the proliferation and adhesion potential of the cells were evaluated by seeding the HGF cells on rectangular samples (n = 18 for each group). The studied groups were tetragonal zirconia (TZr), cubic zirconia (CZr), lithium disilicate (LDS), zirconia-reinforced lithium silicate (ZLS), and hybrid ceramic (HyC) (n = 6 for each studied time). The cell viability (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay was conducted at determined times (24 h, 72 h, and 168 h) to evaluate the cell proliferation. Subsequently, the cultured cells were processed for scanning electron microscope (SEM) observation at each time interval. The surface roughness and wettability of studied ceramics were assessed using a surface profilometer and water contact angle. Differences in the cellular viability, surface roughness (Ra), and wet ability (wetting angle) of studied groups were compared by one-way analysis of variance and the Tukey multiple comparisons test (á = 0.05). Results: The highest percentage of cell viability after 24 h, 72 h, and 168 h cultures was related to ZLS, LDS, and CZr, respectively. The lowest proliferation of fibroblast cells was shown in ZLS compared to other groups. SEM analysis showed that the CZr and LDS groups have better adhesion patterns and morphology. The surface of HyC groups was significantly less rough than other groups. Regarding the water wetting angle (wettability), the TZr and CZr showed significantly larger angles. Conclusion: Within the limitation of this study, it can be concluded that CZr and LDS ceramics had better adhesion patterns and typical morphology. On the other hand, zirconia with a larger wetting angle can reduce the chance of bacteria adhesion to the surface.

Dissimilar joining of NiTi alloys to stainless steel has attracted abundant consideration. In this research, pure nickel powder diluted in PVA adhesive was added to the joint area with different concentrations to eliminate or minimize the brittle intermetallic compounds. Also, thermodynamic concepts of phase stability employing the quaternary CALPHAD method were used to calculate the weld zone's phase stability. The results indicated that laser welding combined with 30% nickel powder addition did not have a noteworthy effect on detracting the content of Fe2Ti in the weld zone. In contrast, adding nickel powder with a concentration of 50% reformed the chemical composition and changed the Fe2Ti primary solidifying phase to more ductile phases of Ni3Ti and γ. The results of equilibrium thermodynamic calculations also predicted that Ni3Ti, γ, and B2-(Fe,Ni)Ti phases are possible to form in this condition. In laser welding with 70% nickel powder, unmixed nickel areas and gas porosities were observed in the weld zone. The superlative mechanical properties were obtained for the samples with 50% nickel powder addition. The microhardness results revealed a diminution of the weld zone's average hardness from 667 HV (without nickel powder addition) to 325 HV (50% nickel powder addition). Evaluation of joint strength revealed the twofold increase in 50% nickel powder added joints compared with conventional samples; the fracture strength and fracture strain reached 310 MPa and 2.9%, respectively. Therefore, Ni powder addition is an effective process for improving the mechanical properties of dissimilar joints of these two alloys.

Leishmaniasis is a tropical disease caused by Leishmania parasites and currently has no licensed vaccines. We developed a dermotropic Leishmania major centrin gene-deleted strain (LmCen–/–) as a live attenuated vaccine. Recent studies have shown that type I interferons (IFNs) play important roles in immunity to parasitic and viral pathogens. However, their relevance in protective immunity following vaccination is not understood. We found that immunization with LmCen–/– induces a transient increase in type I IFN response along with its regulatory factor IRF7 that is downregulated 7–21 days post-immunization, coincided with the induction of a robust Th1 adaptive immune response. Challenge infection with virulent L. donovani parasites showed a significant reduction of splenic and hepatic parasite burden in IRF7–/– mice than wild type mice following immunization with LmCen–/–, suggesting that ablation of type I IFN response is a pre-requisite for the induction of LmCen–/– mediated Th1 immunity against L. donovani infection. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to assess the microtensile bond strength of three universal adhesives to dentin and enamel. Materials and Methods: Sixty extracted human third molar teeth were chosen and divided into six groups regarding the adhesive (G-Premio Bond, Clearfil S3 Bond or Single Bond) and tooth surface. All the applied bonding agents were universal adhesives. The teeth were polished and the adhesives were applied; then the teeth were restored with composite resin. The samples were mounted in acrylic resin and sectioned. The specimens were subjected to a universal testing machine and the microtensile bond strength was measured. The failure mode of each specimen was determined under a stereomicroscope. Data were analyzed using two-way ANOVA (α=0.05). Results: The microtensile bond strength of G-Premio Bond to enamel and dentin was 11.79±8.27 and 17.55±9.47 MPa, respectively which was not significantly different from the values in Single Bond group (15.59±10.66 and 17.19±10.09 MPa to enamel and dentin, respectively; P>0.05). However, the values for Clearfil S3 Bond were 7.11±4.23 and 7.88±8.83 MPa to enamel and dentin, respectively, which were significantly lower than the values for G-Premio Bond (P

In this study, a dental membrane scaffold was fabricated using a 3D printing technique, and the antimicrobial effect of pomegranate seed and peel extract were investigated. For the production of the dental membrane scaffold, a combination of polyvinyl alcohol, starch, and pomegranate seed and peel extracts was used. The aim of the scaffold was to cover the damaged area and aid in the healing process. This can be achieved due to the high antimicrobial and antioxidant content of pomegranate seed and peel extracts (PPE: PSE). Moreover, the addition of starch and PPE: PSE improved the biocompatibility of the scaffold, and their biocompatibility was tested using human gingival fibroblast (HGF) cells. The addition of PPE: PSE into the scaffolds resulted in a significant antimicrobial effect on S. aureus and E. faecalis bacteria. Moreover, different concentrations of starch (1%, 2%, 3% w/v) and pomegranate peel and seed extract (3%, 5%, 7%, 9%, and 11% PE v/v) were analyzed to obtain the ideal dental membrane structure. The optimum starch concentration was chosen as 2% w/v due to it giving the scaffold the highest mechanical tensile strength (23.8607 ± 4.0796 MPa). The pore sizes of each scaffold were studied by SEM analysis, and pore sizes were arranged between 155.86 and 280.96 μm without any plugging problems. Pomegranate seed and peel extracts were obtained by applying the standard extraction method. High-performance liquid chromatography was performed using the diode-array detection (HPLC-DAD) technique to analyze the phenolic content of the pomegranate seed and peel extracts. Two phenolic components of the pomegranate seed and peel extracts were investigated in the following amounts: fumaric acid (17.56 μg analyte/mg extract) and quinic acid (18.79 μg analyte/mg extract) in pomegranate seed extract and fumaric acid (26.95 μg analyte/mg extract) and quinic acid (33.79 μg analyte/mg extract) in pomegranate peel extract.

Background: This study aimed to evaluate the effect of new computer-aided design/computer-aided manufacturing all-ceramic materials on the viability and adhesion properties of human gingival fibroblasts (HGFs). Materials and Methods: In this experimental study, the proliferation and adhesion potential of the cells were evaluated by seeding the HGF cells on rectangular samples (n = 18 for each group). The studied groups were tetragonal zirconia (TZr), cubic zirconia (CZr), lithium disilicate (LDS), zirconia-reinforced lithium silicate (ZLS), and hybrid ceramic (HyC) (n = 6 for each studied time). The cell viability (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay was conducted at determined times (24 h, 72 h, and 168 h) to evaluate the cell proliferation. Subsequently, the cultured cells were processed for scanning electron microscope (SEM) observation at each time interval. The surface roughness and wettability of studied ceramics were assessed using a surface profilometer and water contact angle. Differences in the cellular viability, surface roughness (Ra), and wet ability (wetting angle) of studied groups were compared by one-way analysis of variance and the Tukey multiple comparisons test (á = 0.05). Results: The highest percentage of cell viability after 24 h, 72 h, and 168 h cultures was related to ZLS, LDS, and CZr, respectively. The lowest proliferation of fibroblast cells was shown in ZLS compared to other groups. SEM analysis showed that the CZr and LDS groups have better adhesion patterns and morphology. The surface of HyC groups was significantly less rough than other groups. Regarding the water wetting angle (wettability), the TZr and CZr showed significantly larger angles. Conclusion: Within the limitation of this study, it can be concluded that CZr and LDS ceramics had better adhesion patterns and typical morphology. On the other hand, zirconia with a larger wetting angle can reduce the chance of bacteria adhesion to the surface. [ABSTRACT FROM AUTHOR]

Peri-implantitis is an inflammatory disease with a relevant focus on the long-term success of dental implants and implant-supported prostheses. The present study focuses on the antibacterial effect of the silver nanoparticle and investigated the suppression of dental plaque adhesion on implant abutment and/or superstructure by micro-wave assistant nanosilver coating in vivo and in vitro. Nanosilver coating on pure titanium was prepared by microwave-assisted synthesis, and characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. In vitro studies were conducted to analyze biocompatibility using MTS assay and fluorescence microscopy with human gingival fibroblasts to evaluate antibacterial activity. During the in vivo study, nanosilver coating was applied to the healing abutments, and the prevention of plaque accumulation on nanosilver coating was confirmed by a split-mouth randomized clinical trial. The aggregation of nano-sized particles was found on the titanium surface with an antibacterial effect. The coating had no cytotoxic effect on human gingival fibroblasts. The result of the clinical trial showed that the coating suppressed the dental plaque adhesion on the healing abutments. Nanosilver coating is a promising material with antibacterial properties and can be used for implant abutments and prostheses for preventing peri-implantitis.

The aim of this study was to examine the effect of bioactive glass (BAG) loading on the ion release, pH changes, and cell response of the experimental pit and fissure sealant containing sol–gel derived 58S BAG. The BAG and silica filler in different proportion were incorporated into a resin matrix with the final filler loading of 50% in all groups. The specimens were immersed in deionized water (pH 5.8) or lactic acid solution (pH 4.0) at different time points (6 h, 1, 7, 14, 30, and 45 days) for ion release and pH changes assessment. Biological properties were evaluated using MTS assay, alkaline phosphatase (ALP) assays, and alizarin red staining. In the deionized water, the BAG50% group pH reaches to 9.3 and in lactic acid solution to 4.31 after 45 days. The BAG filler percentage did not have a significant effect on ion release in the deionized water. However, ion release increased with the pH reduction, particularly in the BAG50% group. The BAG50% group showed less cytotoxicity and higher ALP activity and calcified nodule formation. The experimental pit and fissure sealant with 50% BAG filler loading exhibited an appropriate increase in pH elevation, ion release, and cell proliferation and differentiation. Therefore, it can be concluded that this bioactive sealant has the potential to hinder secondary caries and can be used as a caries-inhibiting material. Highlights: A resin-based sealant containing sol-gel derived bioactive glass was developed. The experimental sealant showed acceptable ion release and pH elevation. In-vitro biocompatibility test of the experimental sealant showed favorable results. Addition of 50% 58S BAG filler to resin matrix makes the sealant bioactive. [ABSTRACT FROM AUTHOR]