Microleakage of Silver-Modified Atraumatic Restorative Technique (SMART) Restorations Using Silver Diammine Fluoride and High-Viscosity Glass Ionomer.

Purpose: The purpose of this study was to investigate the microleakage of atraumatic glass ionomer restorations with and without silver diammine fluoride (SDF) application. Restorations with SDF are termed silver-modified atraumatic restorations (SMART). Methods: Sixty carious extracted permanent teeth were randomly allocated to two SMART groups and two control groups (n equals 15 per group) for a total of four groups. After selective caries removal, test specimens were treated with 38 percent SDF and polyacrylic acid conditioner was applied and rinsed; teeth were restored with Fuji IX GP® glass ionomer (n equals 15) or with SMART Advantage™ glass ionomer (SAGI; n equals 15). For control groups, specimens were restored with their respective GI material after selective caries removal, both without SDF. Restored teeth were placed in Dulbecco's Phosphate-Buffered Saline solution at 37 degrees Celsius for 24 hours. Teeth were thermocycled between five and 55 degrees Celsius for 1,000 cycles, stained with two percent basic fuchsin, sectioned, and visually inspected for microleakage utilizing stereomicroscopy on a four-point scale. Data were statistically analyzed using Kruskal-Wallis one-way analysis of variance on ranks using Dunn's method (P<0.05). Results: Microleakage between the two SMART restoration groups was insignificant. SAGI alone demonstrated significantly more microleakage than all other groups. There was no statistical significance between the Fuji IX GP® control group and the two SMART restoration groups. Conclusions: This in vitro study indicated that silver diammine fluoride placed before glass ionomer restoration does not increase microleakage. Polyacrylic acid may be used after SDF placement without increasing microleakage.

Comparing Shear Bond Strength Between Pink Opaquer and Other Tooth-Colored Restorative Materials on Demineralized Dentin Treated with Silver Diammine Fluoride.

Purpose: The purposes of this study were to evaluate the effect of silver diammine fluoride (SDF) on the shear bond strength (SBS) of pink opaquer (PO) compared to resin-modified glass ionomer (RMGI) and conventional composite (COMP) on demineralized dentin, and also to investigate the mode of failure (MOF). Methods: Sixty extracted third molars were prepared, demineralized for 14 days, and divided into four groups: (1) COMP; (2) SDF+PO; (3) SDF+RMGI; and (4) SDF+COMP (restoration size: two by two mm). SBS, MOF, modified adhesive remnant index (MARI), and remnant adhesive volume (RAV) were evaluated using an Instron® machine, light microscopy, 3D digital scanner ( 3Shape©), and GeoMagic Wrap© software. Results: There was no significant difference in SBS (MPa) among the COMP mean??standard deviation (2.5±1.59), SDF+COMP (2.28±1.05), SDF+PO (3.31±2.63), and SDF+RMGI groups (3.74±2.34). There was no significant difference in MOF and MARI among the four groups (P>0.05). There was no significant difference in RAV (mm3) among the COMP (0.5±0.33), SDF+COMP (0.39±0.44), SDF+PO (0.42±0.38), and SDF+RMGI groups (0.42±0.38; P>0.05). A significant correlation existed between MOF and RAV (R equals 0.721; P<0.001). MOF, MARI, and RAV did not show any correlations with SBS (P>0.05). Conclusions: Silver diammine fluoride does not affect shear bond strength between carious dentinal surface and tooth color restorative materials. The amount of material left on the interface is not related to the amount of shear force needed to break the restoration.

Antibacterial and antibiofilm efficacy of Solanum lasiocarpum root extract synthesized silver/silver chloride nanoparticles against Staphylococcus haemolyticus associated with bovine mastitis.

Staphylococcus haemolyticus is a cause of bovine mastitis, leading to inflammation in the mammary gland. This bacterial infection adversely affects animal health, reducing milk quality and yield. Its emergence has been widely reported, representing a significant economic loss for dairy farms. Interestingly, S. haemolyticus exhibits higher levels of antimicrobial resistance than other coagulase-negative Staphylococci. In this study, we synthesized silver/silver chloride nanoparticles (Ag/AgCl-NPs) using Solanum lasiocarpum root extract and evaluated their antibacterial and antibiofilm activities against S. haemolyticus. The formation of the Ag/AgCl-NPs was confirmed using UV-visible spectroscopy, which revealed maximum absorption at 419 nm. X-ray diffraction (XRD) analysis demonstrated the crystalline nature of the Ag/AgCl-NPs, exhibiting a face-centered cubic lattice. Fourier transform infrared (FT-IR) spectroscopy elucidated the functional groups potentially involved in the Ag/AgCl-NPs synthesis. Transmission electron microscopy (TEM) analysis revealed that the average particle size of the Ag/AgCl-NPs was 10 nm. Antimicrobial activity results indicated that the minimum inhibitory concentration (MIC) and maximum bactericidal concentration (MBC) of the Ag/AgCl-NPs treatment were 7.82-15.63 µg/mL towards S. haemolyticus. Morphological changes in bacterial cells treated with the Ag/AgCl-NPs were observed under scanning electron microscopy (SEM). The Ag/AgCl-NPs reduced both the biomass of biofilm formation and preformed biofilm by approximately 20.24-94.66 % and 13.67-88.48 %. Bacterial viability within biofilm formation and preformed biofilm was reduced by approximately 21.56-77.54 % and 18.9-71.48 %, respectively. This study provides evidence of the potential of the synthesized Ag/AgCl-NPs as an antibacterial and antibiofilm agent against S. haemolyticus.

Dual-sensitized heterojunction Ag2S/ZnS/NiS composites with entire visible-light region absorption for ultrasensitive photoelectrochemical detection of tobramycin.

In this study, an ultrasensitive photoelectrochemical (PEC) aptasensor based on dual-sensitized heterojunction Ag2S/ZnS/NiS composites as a signal probe was proposed for the detection of tobramycin (TOB) by combining a cascaded quadratic signal amplification strategy. Specifically, compared to the limited visible light-harvesting capability of single sensitized composites, Ag2S/ZnS/NiS composites with p-n and n-n heterojunction could greatly improve the light energy utilization to tremendously strengthen the optical absorption in the entire visible-light region. Moreover, dual-sensitized heterojunction could effectively hinder the rapid recombination of photoelectrons and holes (carriers) to obtain a good photocurrent for improving the sensitivity of the aptasensor. Furthermore, a cascaded quadratic signal amplification strategy was applied to convert trace target TOB into plentiful gold nanoclusters (Au NCs) labelled double-stranded DNA for the construction of PEC aptasensor, with a broad linear detection range from 0.01 to 100 ng mL-1 and a low detection limit of 3.38 pg mL-1. Importantly, this study provided a versatile and sensitive PEC biosensing platform for TOB analysis, and demonstrated its successful application for TOB detection in milk samples. This protocol provides a novel dual-sensitized heterojunction composites to develop a highly efficient and harmfulless PEC aptasensor, which is expected to be used in food safety, environmental monitoring and other areas.

Acid-Triggered Degradation of Three-In-One Ag2S Quantum Dots for In Situ Ratiometric NIR-II Fluorescence Imaging-Guided Ion/Gas Combination Therapy.

Smart theranostic nanoprobes with the integration of multiple therapeutic modalities are preferred for precise diagnosis and efficient therapy of tumors. However, it remains a big challenge to arrange the imaging and two or more kinds of therapeutic agents without weakening the intended performances. In addition, most existing fluorescence (FL) imaging agents suffer from low spatiotemporal resolution due to the short emission wavelength (<900 nm). Here, novel three-in-one Ag2S quantum dot (QD)-based smart theranostic nanoprobes were proposed for in situ ratiometric NIR-II FL imaging-guided ion/gas combination therapy of tumors. Under the acidic tumor microenvironment, three-in-one Ag2S QDs underwent destructive degradation, generating toxic Ag+ and H2S. Meanwhile, their FL emission at 1270 nm was weakened. Upon introduction of a downconversion nanoparticle (DCNP) as the delivery carrier and NIR-II FL reference signal unit, the formed Ag2S QD-based theranostic nanoprobes could achieve precise diagnosis of tumors through ratiometric NIR-II FL signals. Also, the generated Ag+ and H2S enabled specific ion/gas combination therapy toward tumors. By combining the imaging and therapeutic functions, three-in-one Ag2S QDs may open a simple yet reliable avenue to design theranostic nanoprobes.

Versatile Metal-Organic Framework Incorporating Ag2S for Constructing a Photoelectrochemical Immunosensor for Two Breast Cancer Markers.

Breast cancer poses the significance of early diagnosis and treatment. Here, we developed an innovative photoelectrochemical (PEC) immunosensor characterized by high-level dual photocurrent signals and exceptional sensitivity. The PEC sensor, denoted as MIL&Ag2S, was constructed by incorporating Ag2S into a metal-organic framework of MIL-101(Cr). This composite not only enhanced electron-hole separation and conductivity but also yielded robust and stable dual photocurrent signals. Through the implementation of signal switching, we achieved the combined detection of cancer antigen 15-3 (CA15-3) and carcinoembryonic antigen (CEA) with outstanding stability, reproducibility, and specificity. The results revealed a linear range for CEA detection spanning 0.01-32 ng/mL, with a remarkably low detection limit of 0.0023 ng/mL. Similarly, for CA15-3 detection, the linear range extended from 0.1 to 320 U/mL, with a low detection limit of 0.014 U/mL. The proposed strategy introduces new avenues for the development of highly efficient, cost-effective, and user-friendly PEC sensors. Furthermore, it holds promising prospects for early clinical diagnosis, contributing to potential breakthroughs in medical detection and ultimately improving patient outcomes.

Biogenic synthesis, characterization, and in vitro biological investigation of silver oxide nanoparticles (AgONPs) using Rhynchosia capitata.

The current research aimed to study the green synthesis of silver oxide nanoparticles (AgONPs) using Rhynchosia capitata (RC) aqueous extract as a potent reducing and stabilizing agent. The obtained RC-AgONPs were characterized using UV, FT-IR, XRD, DLS, SEM, and EDX to investigate the morphology, size, and elemental composition. The size of the RC-AgONPs was found to be ~ 21.66 nm and an almost uniform distribution was executed by XRD analysis. In vitro studies were performed to reveal biological potential. The AgONPs exhibited efficient DPPH free radical scavenging potential (71.3%), reducing power (63.8 ± 1.77%), and total antioxidant capacity (88.5 ± 4.8%) to estimate their antioxidative power. Antibacterial and antifungal potentials were evaluated using the disc diffusion method against various bacterial and fungal strains, and the zones of inhibition (ZOI) were determined. A brine shrimp cytotoxicity assay was conducted to measure the cytotoxicity potential (LC50: 2.26 µg/mL). In addition, biocompatibility tests were performed to evaluate the biocompatible nature of RC-AgONPs using red blood cells, HEK, and VERO cell lines (< 200 µg/mL). An alpha-amylase inhibition assay was carried out with 67.6% inhibition. Moreover, In vitro, anticancer activity was performed against Hep-2 liver cancer cell lines, and an LC50 value of 45.94 µg/mL was achieved. Overall, the present study has demonstrated that the utilization of R. capitata extract for the biosynthesis of AgONPs offers a cost-effective, eco-friendly, and forthright alternative to traditional approaches for silver nanoparticle synthesis. The RC-AgONPs obtained exhibited significant bioactive properties, positioning them as promising candidates for diverse applications in the spheres of medicine and beyond.

Electron transfer mediated photo-Fenton-like synergistic catalysis of Fe,Cu-doped MIL-101 coupled with Ag3PO4: Quantitative evaluation and DFT calculations.

Widespread use of tetracycline (TC) results in its persistent residue and bioaccumulation in aquatic environments, posing a high toxicity to non-target organisms. In this study, a bimetal-doped composite material Ag3PO4/MIL-101(Fe,Cu) has been designed for the treatment of TC in aqueous solutions. As the molar ratio of Fe/Cu in composite is 1:1, the obtained material AP/MFe1Cu1 is placed in an aqueous environment under visible light irradiation in the presence of 3 mM peroxydisulfate (PDS), which forms a photo-Fenton-like catalytic system that can completely degrade TC (10 mg/L) within 60 min. Further, the degradation rate constant (0.0668 min-1) is 5.66 and 7.34 times higher than that of AP/MFe and AP/MCu, respectively, demonstrating a significant advantage over single metal-doped catalysts. DFT calculations confirm the strong adsorption capacity and activation advantage of PDS on the composite surface. Therefore, the continuous photogenerated electrons (e-) accelerate the activation of PDS and the production of SO4•-, resulting in the stripping of abundant photogenerated h + for TC oxidation. Meanwhile, the internal circulation of FeⅢ/FeⅡ and CuⅡ/CuⅢ in composite also greatly enhances the photo-Fenton-like catalytic stability. According to the competitive dynamic experiments, SO4•- have the greatest contribution to TC degradation (58.93%), followed by 1O2 (23.80%). The degradation intermediates (products) identified by high-performance liquid chromatography-mass spectrometry (HPLC/MS) technique indicate the involvement of various processes in TC degradation, such as dehydroxylation, deamination, N-demethylation, and ring opening. Furthermore, as the reaction proceeds, the toxicity of the intermediates produced during TC degradation gradually decreases, which can ensure the safety of the aquatic ecosystem. Overall, this work reveals the synergy mechanism of PDS catalysis and photocatalysis, as well as provides technical support for removal of TC-contaminated wastewater.

Exploiting the advantages of cationic copolymers and AgBr nanoparticles to optimize the antibacterial activity of chitosan.

Recently, the chitosan (CS)-based composites have attracted increasing attention for controlling and preventing the spread of pathogenic microorganisms. Herein, an amphiphilic copolymer containing epoxy and quaternary ammonium groups (PBGDBr) was synthesized via three common acrylate monomers. The epoxy groups of this copolymer were then crosslinked with the amino groups of CS to synthesize a natural/synthetic (PBGDBr-C) composite to increase the water solubility of CS under alkaline conditions and enhance its antibacterial activity based on chemical contact-type modes. Moreover, silver bromide nanoparticles (AgBr NPs)-decorated PBGDBr-C (AgBr@PBGDBr-C) composite was prepared, which aimed to endow the final AgBr@PBGDBr-C composite with a photodynamic antibacterial mode relying on the formation of Ag/AgBr nanostructures catalyzed by visible light on AgBr NPs. The results showed that the final composite possessed satisfactory bactericidal effects at concentrations higher than 64 and 128 µg/mL against Escherichia coli and Staphylococcus aureus, respectively. Additionally, The L929 cells treated with the final composite retained high cell viability (>80 %) at a concentration of 128 µg/mL, indicating its low toxicity to L929 cells. Overall, our synthetic strategy exploits a multi-modal system that enables chemical-photodynamic synergies to treat infections caused by pathogenic bacteria while delaying the development of bacterial resistance.

Striking the balance: Unveiling the interplay between photocatalytic efficiency and toxicity of La-incorporated Ag3PO4.

Persistent molecules, such as pesticides, herbicides, and pharmaceuticals, pose significant threats to both the environment and human health. Advancements in developing efficient photocatalysts for degrading these substances can play a fundamental role in remediating contaminated environments, thereby enhancing safety for all forms of life. This study investigates the enhancement of photocatalytic efficiency achieved by incorporating La3+ into Ag3PO4, using the co-precipitation method in an aqueous medium. These materials were utilized in the photocatalytic degradation of Rhodamine B (RhB) and Ciprofloxacin (CIP) under visible light irradiation, with monitoring conducted through high-performance liquid chromatography (HPLC). The synthesized materials exhibited improved stability and photodegradation levels for RhB. Particularly noteworthy was the 2% La3+-incorporated sample (APL2), which achieved a 32.6% mineralization of CIP, nearly three times higher than pure Ag3PO4. Toxicological analysis of the residue from CIP photodegradation using the microalga Raphidocelis subcapitata revealed high toxicity due to the leaching of Ag + ions from the catalyst. This underscores the necessity for cautious wastewater disposal after using the photocatalyst. The toxicity of the APL2 photocatalysts was thoroughly assessed through comprehensive toxicological tests involving embryo development in Danio rerio, revealing its potential to induce death and malformations in zebrafish embryos, even at low concentrations. This emphasizes the importance of meticulous management. Essentially, this study adeptly delineated a thorough toxicological profile intricately intertwined with the photocatalytic efficacy of newly developed catalysts and the resultant waste produced, prompting deliberations on the disposal of degraded materials post-exposure to photocatalysts.

Capacitive and Efficient Near-Infrared Stimulation of Neurons via an Ultrathin AgBiS2 Nanocrystal Layer.

Colloidal nanocrystals (NCs) exhibit significant potential for photovoltaic bioelectronic interfaces because of their solution processability, tunable energy levels, and inorganic nature, lending them chemical stability. Silver bismuth sulfide (AgBiS2) NCs, free from toxic heavy-metal elements (e.g., Cd, Hg, and Pb), particularly offer an exceptional absorption coefficient exceeding 105 cm-1 in the near-infrared (NIR), surpassing many of their inorganic counterparts. Here, we integrated an ultrathin (24 nm) AgBiS2 NC layer into a water-stable photovoltaic bioelectronic device architecture that showed a high capacitive photocurrent of 2.3 mA·cm-2 in artificial cerebrospinal fluid (aCSF) and ionic charges over 10 µC·cm-2 at a low NIR intensity of 0.5 mW·mm-2. The device without encapsulation showed a halftime of 12.5 years under passive accelerated aging test and did not show any toxicity on neurons. Furthermore, patch-clamp electrophysiology on primary hippocampal neurons under whole-cell configuration revealed that the device elicited neuron firing at intensity levels more than an order of magnitude below the established ocular safety limits. These findings point to the potential of AgBiS2 NCs for photovoltaic retinal prostheses.

Novel Ag3PO4/ZnWO4-modified graphite felt electrode for photoelectrocatalytic removal of harmful algae: Performance and mechanism.

A novel Ag3PO4/ZnWO4-modified graphite felt electrode (AZW@GF) was prepared by drop coating method and applied to photoelectrocatalytic removal of harmful algae. Results showed that approximately 99.21% of chlorophyll a and 91.57% of Microcystin-LR (MCLR) were degraded by the AZW@GF-Pt photoelectrocatalytic system under the optimal operating conditions with a rate constant of 0.02617 min-1 and 0.01416 min-1, respectively. The calculated synergistic coefficient of photoelectrocatalytic algal removal and MC-LR degradation by the AZW@GF-Pt system was both larger than 1.9. In addition, the experiments of quenching experiments and electron spin resonance (ESR) revealed that the photoelectrocatalytic reaction mainly generated •OH and •O2- for algal removal and MC-LR degradation. Furthermore, the potential pathway for photoelectrocatalytic degradation of MC-LR was proposed. Finally, the photoelectrocatalytic cycle algae removal experiments were carried out on AZW@GF electrode, which was found to maintain the algae removal efficiency at about 91% after three cycles of use, indicating that the photoelectrocatalysis of AZW@GF electrode is an effective emergency algae removal technology.

Polyvalent Aptamer-Functionalized NIR-II Quantum Dots for Targeted Theranostics in High PD-L1-Expressing Tumors.

Ag2S quantum dots (QDs) show superior optical properties in the NIR-II region and display significant clinical potential with favorable biocompatibility. However, inherent defects of low targeting and poor solubility necessitate practical modification methods to achieve the theranostics of Ag2S QDs. Herein, we used rolling circle amplification (RCA) techniques to obtain long single-stranded DNA containing the PD-L1 aptamer and C-rich DNA palindromic sequence. The C-rich DNA palindromic sequences can specifically chelate Ag2+ and thus serve as a template to result in biomimetic mineralization and formation of pApt-Ag2S QDs. These QDs enable specific targeting and illuminate hot tumors with high PD-L1 expression effectively, serving as excellent molecular targeted probes. In addition, due to the high NIR-II absorption of Ag2S QDs, pApt-Ag2S QDs exhibit remarkable photothermal properties. And besides, polyvalent PD-L1 aptamers can recognize PD-L1 protein and effectively block the inhibitory signal of PD-L1 on T cells, enabling efficient theranostics through the synergistic effect of photothermal therapy and immune checkpoint blocking therapy. Summary, we enhance the biological stability and antibleaching ability of Ag2S QDs using long single-stranded DNA as a template, thereby establishing a theranostic platform that specifically targets PD-L1 high-expressing inflamed tumors and demonstrates excellent performance both in vitro and in vivo.

Potential-selective electrochemiluminescence of AgInS2/ZnS nanocrystals and its immunoassay application.

Potential-selective electrochemiluminescence (ECL) with tunable maximum-emission-potential ranging from 0.95 to 0.30 V is achieved using AgInS2/ZnS nanocrystals, which is promising in the design of multiplexed bioassay on commercialized ECL setups. The model system AgInS2/ZnS/N2H4 exhibits efficient ECL around 0.30 V and can be exploited for sensitive immunoassays with less electrochemical interference and crosstalk.

Understanding the different effects of fouling mechanisms on working and reference electrodes in fast-scan cyclic voltammetry for neurotransmitter detection.

Fast-scan cyclic voltammetry (FSCV) is a widely used technique for detecting neurotransmitters. However, electrode fouling can negatively impact its accuracy and sensitivity. Fouling refers to the accumulation of unwanted materials on the electrode surface, which can alter its electrochemical properties and reduce its sensitivity and selectivity. Fouling mechanisms can be broad and may include biofouling, the accumulation of biomolecules on the electrode surface, and chemical fouling, the deposition of unwanted chemical species. Despite individual studies discussing fouling effects on either the working electrode or the reference electrode, no comprehensive study has been conducted to compare the overall fouling effects on both electrodes in the context of FSCV. Here, we examined the effects of biofouling and chemical fouling on the carbon fiber micro-electrode (CFME) as the working electrode and the Ag/AgCl reference electrode with FSCV. Both fouling mechanisms significantly decreased the sensitivity and caused peak voltage shifts in the FSCV signal with the CFME, but not with the Ag/AgCl reference electrode. Interestingly, previous studies have reported peak voltage shifts in FSCV signals due to the fouling of Ag/AgCl electrodes after implantation in the brain. We noticed in a previous study that energy-dispersive spectroscopy (EDS) spectra showed increased sulfide ion concentration after implantation. We hypothesized that sulfide ions may be responsible for the peak voltage shift. To test this hypothesis, we added sulfide ions to the buffer solution, which decreased the open circuit potential of the Ag/AgCl electrode and caused a peak voltage shift in the FSCV voltammograms. Also, EDS analysis showed that sulfide ion concentration increased on the surface of the Ag/AgCl electrodes after 3 weeks of chronic implantation, necessitating consideration of sulfide ions as the fouling agent for the reference electrodes. Overall, our study provides important insights into the mechanisms of electrode fouling and its impact on FSCV measurements. These findings could inform the design of FSCV experiments, with the development of new strategies for improving the accuracy and reliability of FSCV measurements in vivo.

Silver vanadate nanomaterial incorporated into heat-cured resin and coating in printed resin - Antimicrobial activity in two multi-species biofilms and wettability.

OBJECTIVES: To incorporate the nanostructured silver vanadate decorated with silver nanoparticles (AgVO3) into denture base materials: heat-cured (HC) and 3D printed (3DP) resins, at concentrations of 2.5 %, 5 %, and 10 %; and to evaluate the antimicrobial activity in two multi-species biofilm: (1) Candida albicans, Candida glabrata, and Streptococcus mutans, (2) Candida albicans, Pseudomonas aeruginosa, and Staphylococcus aureus, and the wettability. METHODS: The AgVO3 was added to the HC powder, and printed samples were coated with 3DP with AgVO3 incorporated. After biofilm formation, the antimicrobial activity was evaluated by colony forming units per milliliter (CFU/mL), metabolic activity, and epifluorescence microscopy. Wettability was assessed by the contact angles with water and artificial saliva. RESULTS: In biofilm (1), HC-5 % and HC-10 % showed activity against S. mutans, HC-10 % against C. glabrata, and HC-10 % and 3DP-10 % had higher CFU/mL of C. albicans. 3DP-5 % had lower metabolic activity than the 3DP control. In biofilm (2), HC-10 % reduced S. aureus and P. aeruginosa, and HC-5 %, 3DP-2.5 %, and 3DP-5 % reduced S. aureus. 3DP incorporated with AgVO3, HC-5 %, and HC-10 % reduced biofilm (2) metabolic activity. 3DP-5 % and 3DP-10 % increased wettability with water and saliva. CONCLUSION: HC-10 % was effective against C. glabrata, S. mutans, P. aeruginosa, and S. aureus, and HC-5 % reduced S. mutans and S. aureus. For 3DP, 2.5 % and 5 % reduced S. aureus. The incorporation of AgVO3 into both resins reduced the metabolic activity of biofilms but had no effect on C. albicans. The wettability of the 3DP with water and saliva increased with the addition of AgVO3. CLINICAL SIGNIFICANCE: The incorporation of silver vanadate into the denture base materials provides antimicrobial efficacy and can prevent the aggravation of oral and systemic diseases. The incorporation of nanomaterials into printed resins is challenging and the coating is an alternative to obtain the inner denture base with antimicrobial effect.

A novel fluorescent sensor for selective rifampicin detection based on the bio-inspired molecularly imprinted polymer-AgInS2/ZnS quantum dots.

A fluorescent sensing material based on the ternary core-shell quantum dots with outstanding optical properties and a bio-inspired molecularly imprinted polymer (MIP) as a recognition element has been prepared for selective detection of rifampicin (RFP). Firstly, AgInS2/ZnS core/shell quantum dots (ZAIS QDs) were prepared by a hydrothermal process. Then, the fluorescent sensor was prepared by coating these QDs by a dopamine-based MIP layer. The fluorescence of MIP@ZAIS QDs was quenched by RFP probably due to the photoinduced electron transfer process. The quenching constant was much higher for MIP@ZAIS QDs than the non-imprinted polymer@QDs, indicating that MIP@ZAIS QDs could selectively recognize RFP. Under the optimized conditions, the sensor had a good linear relationship at the RFP concentration range of 5.0 to 300 nM and the limit of detection was 1.25 nM. The respond time of the MIP@ZAIS QDs was 5 min, and the imprinting factor was 6.3. It also showed good recoveries ranging from 98 to 101%, for analysis of human plasma samples. The method is simple and effective for the detection of RFP and offers a practical application for the rapid analysis of human plasma samples.

Phase Engineered CuxS-Ag2S with Photothermoelectric Activity for Enhanced Multienzyme Activity and Dynamic Therapy.

The insufficient exposure sites and active site competition of multienzyme are the two main factors to hinder its therapeutic effect. Here, a phase-junction nanomaterial (amorphous-crystalline CuxS-Ag2S) is designed and prepared through a simple room temperature ion-exchange process. A small amount of Ag+ is added into Cu7S4 nanocrystals, which transforms Cu7S4 into amorphous phased CuxS and produces crystalline Ag2S simultaneously. In this structure, the overhanging bonds on the amorphous CuxS surface provide abundant active sites for optimizing the therapeutic activity. Meanwhile, the amorphous state enhances the photothermal effect through non-radiative relaxation, and due to its low thermal resistance, phase-junction CuxS-Ag2S forms a significant temperature gradient to unlock the optimized thermo-electrodynamic therapy. Furthermore, benefiting from the high asymmetry of the amorphous state, the material forms a spin-polarized state that can effectively inhibit electron-hole recombination. In this way, the thermoelectric effect can facilitate the enzyme-catalyzed cycle by providing electrons and holes, enabling an enhanced coupling of thermoelectric therapy with multienzyme activity, which induces excellent anti-tumor performance. More importantly, the catalytic process simulated by density-functional theory proves that Ag+ alleviates the burden on the Cu sites through favorable adsorption of O2 and prevents active site competition.

Mechanical and microbiological properties of orthodontic resin modified with nanostructured silver vanadate decorated with silver nanoparticles (ßAgVO3).

OBJECTIVE: To investigate the impact of incorporating the antimicrobial nanomaterial ß-AgVO3 into orthodontic resin, focusing on degree of conversion, surface characteristics, microhardness, adhesion properties, and antimicrobial activity. METHODS: The 3 M Transbond XT resin underwent modification, resulting in three groups (Control, 2.5% addition, 5% addition) with 20 specimens each. Fourier transform infrared spectroscopy assessed monomer conversion. Laser confocal microscopy examined surface roughness, and microhardness was evaluated using Knoop protocols. Shear strength was measured before and after artificial aging on 36 premolar teeth. Microbiological analysis against S. mutans and S. sanguinis was conducted using the agar diffusion method. RESULTS: Degree of conversion remained unaffected by time (P = 0.797), concentration (P = 0.438), or their interaction (P = 0.187). The 5% group exhibited the lowest surface roughness, differing significantly from the control group (P = 0.045). Microhardness showed no significant differences between concentrations (P = 0.740). Shear strength was highest in the control group (P < 0.001). No significant differences were observed in the samples with or without thermocycling (P = 0.759). Microbial analysis revealed concentration-dependent variations, with the 5% group exhibiting the largest inhibition halo (P < 0.001). CONCLUSIONS: Incorporating ß-AgVO3 at 2.5% and 5% concentrations led to significant differences in surface roughness, adhesion, and antimicrobial activity. Overall, resin modification positively impacted degree of conversion, surface characteristics, microhardness, and antimicrobial activity. Further research is warranted to determine clinically optimal concentrations that maximize antimicrobial benefits while minimizing adverse effects on adhesion properties. CLINICAL SIGNIFICANCE: Incorporating ß-AgVO3 into orthodontic resin could improve patient quality of life by prolonging intervention durability and reducing the impact of cariogenic microorganisms. The study's findings also hold promise for the industry, paving the way for the development of new materials with antimicrobial properties for potential applications in the health sector.

Silver Compounds for Caries Management.

Silver metal and compounds have antibacterial properties, although their action's mechanisms are not fully understood. Scientists generally consider that silver disrupts the bacterial cell wall. It causes a structural change in the bacterial cell membrane and cytoplasm. It also stops deoxyribonucleic acid replication, resulting in inactivating enzymatic activity and cell death. The antimicrobial effect of silver-containing compounds relies on the release of bioactive silver ions. Hence, silver metal and compounds have been used in medicine to prevent infection for hundreds of years. Silver metal and compounds are also used as antibacterial agents in dentistry. Studies have shown that silver compounds are effective in the management of dental caries. Fluoride-containing silver compounds have been found in experiments to be beneficial at remineralising dental cavities. Silver diamine fluoride (SDF) can assist in preventing and arresting tooth cavities. The World Health Organization included SDF in its Model List of Essential Medicine for both adults and children in 2021. Clinicians also use SDF to manage dentine hypersensitivity as well as to inhibit growth of periodontal pathogens. However, traditional silver compounds cause tooth discolouration because of the silver-staining effect. These side effects of their applications depend on the amount applied and the frequency of application. Researchers are developing nanosilver fluoride and silver nanoparticles to overcome the staining. This review gives an overview of the antibacterial mechanism of silver compounds, namely silver nitrate, silver fluoride, SDF, silver nanoparticles, and nano silver fluoride for caries management. The outlook for the future development of silver compounds will be discussed.