Effect of silver diamine fluoride application on the microtensile bond strength of three commonly used restorative materials in primary teeth: An ultrastructural study.

INTRODUCTION: Caries in primary teeth rapidly advances owing to its thin structure, thereby requiring restoration. However, restorations often fail due to various causes such as secondary caries and reduced microtensile bond strength (µTBS), which calls for the use of antimicrobial agents such as silver diamine fluoride (SDF). AIM: This study aims to measure and analyse the effect of SDF application on the µTBS of three regularly used restorative materials to dentin of primary teeth as well as compare the types of bond failure interfaces under SEM. MATERIALS AND METHODS: The study comprised 60 samples equally divided into six groups among three restorative materials, namely, glass ionomer cement (GIC, Groups I and II), resin-modified glass ionomer cement (RMGIC, Groups III and IV), and composite resin (Groups V and VI) with subdivisions of A and B, where A represented samples with SDF application and B represented samples without SDF application. RESULTS AND OBSERVATIONS: It was observed that µTBS of RMGIC to sound and carious dentin irrespective of SDF application was found to be statistically significant (P < 0.05), and when GIC, RMGIC, and composite resins were compared to both sound and carious dentin irrespective of SDF application, it was statistically significant (P < 0.05). SEM analysis revealed predominantly cohesive failures among all the groups. CONCLUSION: Based on the results, it was concluded that SDF has no adverse effect on the µTBS of GIC, RMGIC, and composite resin to both carious and sound dentin of primary teeth.

AgI Precipitation Induced Polarity Reversal with Formation of Z-Type Heterojunction for Photoelectrochemical Sensing.

Regulating photocurrent polarity is highly attractive for fabricating photoelectrochemical (PEC) biosensors with improved sensitivity and accuracy in practical samples. Here, a new approach that adopts the in situ generated AgI precipitate and AgNCs to reversal Bi2WO6 polarity with formation of Z-type heterojunction was proposed for the first time, which coupled with a high-efficient target conversion strategy of exonuclease III (Exo III)-assisted triple recycling amplification for sensing miRNA-21. The target-related DNA nanospheres in situ generated on electrode with loading of plentiful AgI and AgNCs not only endowed the photocurrent of Bi2WO6 switching from the anodic to cathodic one due to the changes in the electron transfer pathway but also formed AgI/AgNCs/Au/Bi2WO6 Z-type heterojunction to improve the photoelectric conversion efficiency for acquiring extremely enhanced PEC signal, thereby significantly avoiding the problem of high background signal derived from traditional unidirectional increasing/decreasing response and false-positive/false-negative. Experimental data showed that the PEC biosensor had a low detection limit down to 0.085 fM, providing a new polarity-reversal mechanism and expected application in diverse fields, including biomedical research and clinical diagnosis.

Effectiveness of silver diamine fluoride (SDF) in arresting coronal dental caries in children and adolescents: a systematic review.

Dental caries remains a significant public health issue for children globally, leading to adverse effects on health and development. Silver diamine fluoride (SDF) is a potential preventive agent that can prevent caries progression in children. This systematic review examined the effectiveness of silver diamine fluoride in arresting caries compared to other fluorides. An electronic search of MEDLINE, PubMed, EMBASE, Cochrane, Web of Science, Scopus databases was carried out examining articles in English from 2001 to 2023. Studies included in the analysis examined the application of SDF in children and adolescents with coronal caries lesions on primary teeth or permanent first molars. Fifteen studies, involving a total of 7895 children, were incorporated. The application regimen varied across studies. Most studies in this review consistently suggested that SDF is effective in arresting caries. An annual application of SDF effectively reduced Streptococcus mutans count. Adverse effects were primarily tooth staining and less commonly, oral mucosal irritation. A majority of studies showed a high risk of bias due to methodological insufficiencies. Overall, the evidence suggests that SDF is effective in arresting dental caries in children. It offers a viable, cost-effective, and minimally invasive treatment option, particularly suitable for use in low-resource settings. However, the aesthetic concern of tooth staining with SDF use remains a challenge. Further well-designed clinical trials may provide a fuller picture of SDF which can shape public health policy and shift towards a minimally invasive treatment approach.

Can silver diamine fluoride reduce invasive treatments with general anesthesia?

This study aims to retrospectively evaluate the differences in dental treatments rendered in general anesthesia (GA) for patients who did or did not receive application of silver diamine fluoride (SDF) prior to GA. 1559 patients (≤6 years) who completed treatment with GA for caries at University of California San Francisco (UCSF) between 2015 and 2019 were included in the study. At baseline patients' electronic health record was reviewed to collect planned treatment, complete dental treatment and demographics. Patients were identified as SDF group (N = 335, 21.49%) or comparison (N = 1224, 78.51%). Dental treatments rendered were compared between the SDF and comparison group with multi-variable regression, including variables for demographics and clinical findings at baseline. The initial analysis identified variations in gender, age, dental pain, pulp involvement, and initial treatment plans between the SDF and comparison groups at baseline. In an unadjusted analysis, the SDF group displayed a statistically significant increase in the number of crown procedures but a notable decrease in the number of pulp therapy and extraction treatments completed (p < 0.05). An adjusted multivariable model affirmed the inverse relationship between SDF application and completion of pulp therapy and extractions at the time of GA (p < 0.05). No significant association was identified with the total number of crowns needed and SDF. The model further indicated a positive correlation between the total count of pulp therapy and extractions completed with patient age and the wait-time for GA. In conclusion, pre-GA application of SDF to carious primary teeth is negatively correlated with completed pulp therapy and extraction. SDF application prior to dental treatment with GA may be a valuable tool to reduce invasive dental procedures in GA.

An open-label, parallel-group, randomized clinical trial of different silver diamine fluoride application intervals to arrest dental caries.

BACKGROUND: Silver diamine fluoride (SDF) is an antimicrobial agent and alternative treatment option that can be used to arrest dental decay. While there is optimism with SDF with regard to caries management, there is no true consensus on the number and frequency of applications for children. The purpose of this study was to examine the effectiveness of 38% SDF to arrest early childhood caries (ECC) at three different application regimen intervals. METHODS: Children with teeth that met International Caries Detection and Assessment System codes 5 or 6 criteria were recruited from community dental clinics into an open-label, parallel-group, randomized clinical trial from October 2019 to June 2021. Participants were randomized to one of three groups using sealed envelopes that were prepared with one of three regimens inside: visits one month, four months, or six months apart. Participants received applications of 38% SDF, along with 5% sodium fluoride varnish (NaFV), at the first two visits to treat cavitated carious lesions. Lesions were followed and arrest rates were calculated. Lesions were considered arrested if they were hard on probing and black in colour. Statistics included descriptive and bivariate analyses (Kruskal one-way analysis of variance and Pearson's Chi-squared test). A p-value of ≤ 0.05 was considered significant. RESULTS: Eighty-four children participated in the study (49 males and 35 females, mean age: 44.4 ± 14.2 months). Treatment groups were well matched with 28 participants per group. A total of 374 teeth and 505 lesions were followed. Posterior lesions represented only 40.6% of affected surfaces. Almost all SDF treated lesions were arrested for the one-month (192/196, 98%) and four-month (159/166, 95.8%) interval groups at the final visit. The six-month group experienced the lowest arrest rates; only 72% (103/143) of lesions were arrested (p < 0.001). The duration of application intervals was inversely associated with improvements in arrest rates for all lesions. CONCLUSIONS: Two applications of 38% SDF and 5% NaFV in one-month and four-month intervals were comparable and very effective in arresting ECC. Applications six months apart were less effective and could be considered inferior treatment. TRIAL REGISTRATION: ClinicalTrials.gov NCT04054635 (first registered 13/08/2019).

Synthesis and analysis of multifunctional graphene oxide/Ag2O-PVA/chitosan hybrid polymeric composite for wound healing applications.

The requirement for accurate treatments for skin diseases and wounds, generated a rising interest towards multifunctional polymer composites, that are capable of mimicking the natural compositions in human body. Also, electroactive composite films disseminate endogenous electrical stimulations that encourage cell migration and its proliferation at wound site, proposing greater opportunities in upgrading the conventional wound patches. In this work, the composite film made of graphene oxide, Ag2O, PVA and chitosan were developed for wound healing applications, by the solution casting method. The even dispersibility of nanofiller in polymeric matrix was validated from the physicochemical analyses. The increment in roughness of the composite film surface was noted from AFM images. The thermal stability and porous nature of the polymer composite were also verified. A conductivity value of 0.16 × 10-4 Scm-1 was obtained for the film. From MTT assay, it was noted that the films were non-cytotoxic and supported cell adhesion along with cell proliferation of macrophage (RAW 264.7) cells. Moreover, the composite film also demonstrated non-hemolytic activity of <2 %, as well as excellent antibacterial activity towards E. coli and S. aureus. Thus, the obtained results validated that the prepared composite film could be chosen as an innovative candidate for developing state-of-the-art wound dressings.

Physicochemical and photocatalytic properties of Ag2CrO4/Fe2O3/CeO2 ternary nanocomposite.

The study presents Ag2CrO4/Fe2O3/CeO2 ternary nanocomposite, based on Fe2O3/CeO2 binary composites, which demonstrated excellent photocatalytic performance in the photodegradation of methylene blue under solar irradiation. The Ag2CrO4/Fe2O3/CeO2 nanocomposites was orthorhombic, ilmenite, and cubic-fluorite phases of Ag2CrO4, Fe2O3, and CeO2, respectively, according to the XRD examination. A strong bond between Ag2CrO4, Fe2O3, and CeO2 within the nanocomposite was demonstrated by the SEM and TEM investigations. Moreover, it was discovered that the coupling of Ag2CrO4 and Fe2O3 caused a red shift and moved CeO2 absorption edge from the UV to the visible spectrum. The reason behind this is that the band gap of CeO2 reduced 2.85 to 2.69 eV and the absorbance band intensity increased in visible region. Utilizing visible light, Ag2CrO4/Fe2O3/CeO2 ternary nanocomposites exhibit enhanced photocatalytic properties (98.90%) for the degradation of methylene blue (MB) within 100 min. The long-term reliability and recyclability of the photocatalyst were explored through 3 successive cycles. An active radical quenching test was conducted to elucidate the involvement of O2 - and OH which are the primary reactive species in the photocatalytic breakdown of MB. Ag2CrO4/Fe2O3/CeO2 ternary nanocomposites displayed notable improvements in photodegradation activity, making them well suited for the effective removal of hazardous dyes present in textile effluents.

Remineralizing effect of NSF on artificial enamel caries.

INTRODUCTION: Nanotechnology offers new approaches and endless opportunities for remineralizing tooth decay without being toxic or causing allergies. This study aimed to determine the effect of nanosilver fluoride (NSF) on the remineralization potential of enamel caries-like lesions compared to 5% sodium fluoride varnish in permanent teeth. METHODS: Fifteen teeth (molars and premolars) were gathered, cleaned, and polished using a scaler. After sectioning the teeth mesiodistally and removing the roots, the thirty specimens were subjected to a demineralized solution to induce early enamel lesions and then assigned randomly into two equal groups. The test materials were applied, and then all the specimens were subjected to a pH cycling model for 30 days. DIAGNOdent and surface roughness were investigated, and an evaluation of the enamel Ca and P weight% for Ca/P ratio calculation was done using SEM-EDX to analyze the specimens at the end of the study. The data were analyzed using an independent t-test. RESULTS: The mean values for the DIAGNOdent measurements for NSF and NaF at baseline and after demineralization were not significantly different (p > 0.05). After treatment, NaF varnish showed a significantly higher mean DIAGNOdent measurement (11.8 ± 5.80) than NSF (4.7 ± 1.6). The mean surface roughness of the NaF group (1.64 ± 0.39) was much higher than NSF's mean surface roughness (1.07 ± 0.21). Specimens treated with NSF had statistically significant smoother surfaces (p < 0.001). The NSF group had a higher mean Ca/P ratio (2.9 ± 0.35) than NaF (2.2 ± 0.11). This difference was statistically significant (p = 0.012). CONCLUSION: The study reveals that nano silver fluoride is a more effective treatment than sodium fluoride varnish in enhancing teeth's clinical characteristics, particularly in terms of mineral content and surface roughness, suggesting it could be an improved strategy to prevent dental caries and maintain enamel integrity.

Effects of light curing on silver diamine fluoride-treated carious lesions: A systematic review.

OBJECTIVE: This systematic review aims to evaluate the potential benefits and underlying mechanisms of combining SDF with light curing, based on available studies. MATERIALS AND METHODS: A systematic search of publications was conducted with the keywords "silver diamine fluoride" or "silver fluoride" and "dental light curing," "LED curing," "dental laser," and "dental polymerization" in 4 databases: PubMed, EBSCO, Scopus, and Google Scholar to identify English-language articles published up to March 2023. Duplicate publications were deleted. Two reviewers screened the titles and abstracts and excluded irrelevant publications. The full text of the remaining publications was retrieved. Studies investigating the effect of light-curing on SDF-treated carious lesions were included. RESULTS: The 175 publications initially found included 5 laboratory studies investigating the effects of light curing on 38% SDF-treated dentine carious lesions, but no clinical study was found. Four of these studies were conducted on extracted primary teeth, and one was on extracted permanent teeth. SDF with light curing increased microhardness (n = 3, p < .05) showed a higher mineral density (n = 1, p < .041) and had more silver ion precipitation in infected dentine (n = 1, p < .016) compared to SDF without light curing. Moreover, no significant differences in the antibacterial activity were observed between SDF with light curing and SDF alone (n = 1, p > .05). CONCLUSION: Drawing from the limited number of laboratory studies, incorporating light curing subsequent to the SDF application yields potential favorable outcomes that include augmented microhardness, elevated mineral density, and heightened silver ion precipitation within infected dentine. Future clinical research is required to confirm or refute the benefit of light curing on SDF-treated carious lesions.

Harmonic Generation in Molecular Ag2S Plasma.

The molecular laser-induced plasma (LIP) produced during the ablation of silver sulfide (Ag2S) was used as a medium for high-order harmonic generation in the extreme ultraviolet range. The role of LIP formation, the plasma components, and the geometry of plasma in the harmonic conversion efficiency was analyzed. We also analyzed the influence of the driving pulses (chirp, single-color pump, two-color pump, and delay between heating and converting pulses) on the harmonic yield in Ag2S LIP. The application of molecular plasma was compared with the application of atomic plasma, which comprised similar metallic elements (Ag) as well as other metal LIPs. The harmonics from the Ag2S LIP were 4 to 10 times stronger than those from the Ag LIP. The harmonics up to the 59th order were achieved under the optimal conditions for the molecular plasma.

Fabrication of smart sunlight window using silver vanadate nanorods (ß-AgVO3) and its effect on phytochemical properties of several agricultural species.

Silver vanadate nanorods were synthesized for the first time via co-precipitation, followed by ambient drying. X-ray diffraction (XRD), energy dispersive X-ray (EDX), and scanning electron microscope (SEM) analyses were utilized to investigate the structure and morphology of the nanorods. The results of these analyses confirmed the fabrication of silver vanadate nanorods. Then, to check the ability of these nanostructures to be used in the smart window, their optical properties, including the visible-ultraviolet absorption spectrum and photoluminescence (PL), were studied. The results showed that this nanostructure has maximum absorption and emission at wavelengths of 530 and 670 nm, respectively. Next, the new smart window was made with a layer of silver vanadate nanorods, and wheat, barley, millet, and beet were placed under this smart window to perform phytochemical tests. It was observed that silver vanadate nanorods could shift the green wavelength to higher wavelengths and efficiently improve the phytochemical properties of the mentioned plants.

High-efficiency removal of microcystis aeruginosa using Z-scheme AgBr/NH2-MIL-125(Ti) photocatalyst with superior visible-light absorption: Performance insights and mechanisms.

Algal blooms have become a widespread concern for drinking water production, threatening ecosystems and human health. Photocatalysis, a promising advanced oxidation process (AOP) technology for wastewater treatment, is considered a potential measure for in situ remediation of algal blooms. However, conventional photocatalysts often suffer from limited visible-light response and rapid recombination of photogenerated electron-hole pairs. In this study, we prepared a Z-scheme AgBr/NH2-MIL-125(Ti) composite with excellent visible light absorption performance using co-precipitation to efficiently inactivate Microcystis aeruginosa. The degradation efficiency of AgBr/NH2-MIL-125(Ti) for chlorophyll a was 98.7 % after 180 min of visible light irradiation, significantly surpassing the degradation rate efficiency of AgBr and NH2-MIL-125(Ti) by factors of 3.20 and 36.75, respectively. Moreover, the removal rate was maintained at 91.1 % even after five times of repeated use. The experimental results indicated that superoxide radicals (•O2-) were the dominant reactive oxygen species involved. The photocatalytic reaction altered the morphology and surface charge of algal cells, inhibited their metabolism, and disrupted their photosynthetic and antioxidant systems. In conclusion, this study presents a promising material for the application of photocatalytic technology in algal bloom remediation.

Silver diamine fluoride in preventing enamel erosion: An in vitro study with salivary pellicle.

OBJECTIVES: To compare the prevention of enamel erosion and discolouring effect with a single and two weekly topical applications of silver diamine fluoride (SDF) solution. METHODS: Human enamel blocks were divided into four groups. Group 1 (SDF2) received two weekly applications of SDF solution (Advantage Arrest: 260,000 ppm Ag, 44,300 ppm F, pH 9.1). Group 2 (SDF1) received a single application of SDF solution. Group 3 (SNF, Positive Control) received daily application of stannous-chloride/amine-fluoride/sodium-fluoride solution (Elmex® Enamel professional: 800 ppm Sn(II), 500 ppm F, pH 4.5). Group 4 (DW, Negative Control) received daily application of deionised water. The treated blocks were subjected to a 14-day erosive challenge. Crystal characteristics, elemental composition, surface morphology, percentage of surface microhardness loss (%SMHL), surface loss, and total colour change (ΔE) of the blocks were investigated using X-ray diffraction (XRD), energy-dispersive spectrometry (EDS) and scanning electron microscopy (SEM), Vickers' hardness testing, non-contact profilometry, and digital spectrophotometry, respectively. RESULTS: XRD and EDS revealed precipitates of silver for SDF2 and SDF1 and tin for SNF. SEM showed prominent etched enamel pattern on DW than the other three groups. The%SMHL (%) of SDF2, SDF1, SNF, and DW were 26.6 ± 2.9, 33.6 ± 2.8, 38.9 ± 2.9, and 50.5 ± 2.8 (SDF2SDF1=SNF>DW, p < 0.05). CONCLUSION: Two weekly applications was more effective than a single application of SDF in preventing enamel erosion, though it caused more discolouration. CLINICAL SIGNIFICANCE: Topical application of 38 % SDF with two weekly applications protocol is effective in preventing enamel erosion.

A randomised clinical trial to arrest caries using silver diamine fluoride therapy with two postoperative instructions.

OBJECTIVE: The objective of this study is to investigate the beneficial effect of not rinsing for 30 min in arresting early childhood caries after SDF therapy. METHODS: This randomised clinical trial recruited 3- to 4-year-old kindergarten children with active (soft) dentine caries. A questionnaire was sent to the parents to collect children's demographic data and oral health-related behaviours. A dentist conducted an oral examination and measured the caries experience using dmft index and oral hygiene using visible plaque index. After 38 % SDF therapy, the children were randomly allocated into two groups. Children in group A were instructed to rinse with water immediately, whereas children in group B were asked to refrain from rinsing, drinking, or eating for 30 min. After six months, the same examiner determined the lesion activity (active/arrest) of the SDF-treated carious tooth surface. Generalized Estimating Equations was used to compare the proportion of caries arrest (caries-arrest rate) between the two groups. RESULTS: This study recruited 298 children with 1,158 decayed tooth surfaces receiving SDF therapy at baseline and evaluated 275 (92 %) children with 1,069 (92 %) SDF-treated tooth-surface at the six-month examination. The demographic background, oral hygiene and caries status of two groups were comparable at baseline (p > 0.05). The caries-arrest rate for group A and group B were 65 % (337/519) and 61 % (338/550), respectively (p = 0.28). CONCLUSION: This randomised clinical trial found not rinsing for 30 min after SDF therapy is not better than immediate rinsing in arresting early childhood caries. CLINICAL SIGNIFICANCE: Topical SDF application leaves an unpleasant taste in the mouth, which may affect the acceptance or even rejection of SDF therapy among young children. This study provides clinicians with information to make their decision on postoperative instruction after SDF therapy.

Preventing proximal enamel caries in neighboring tooth with glass ionomer cement restoration and silver diamine fluoride pretreatment.

OBJECTIVE: To investigate caries preventive effects of 38 % silver diamine fluoride (SDF) pretreatment on neighboring tooth proximal to glass ionomer cement (GIC), including conventional GIC (CGIC) and resin-modified GIC (RMGIC) restorations in an in vitro model. METHODS: HUMAN TOOTH BLOCKS WERE RESTORED WITH: SDF+CGIC (Group 1), CGIC (Group 2), SDF+RMGIC (Group 3) or RMGIC (Group 4). Enamel specimen simulating proximal surface of neighboring tooth was placed in proximity to the restorations. The specimen underwent cariogenic challenge with cross-kingdom biofilm of Streptococcus mutans, Lacticaseibacillus casei and Candida albicans. After cariogenic challenge, the biofilm's growth kinetics, viability, and morphology were evaluated by propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR), confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM), respectively. The enamel lesion depth, surface morphology and crystal characteristics were determined by micro-computed tomography (micro-CT), SEM and X-ray diffraction (XRD), respectively. RESULTS: PMA-qPCR demonstrated lower microbial growth in Group 1 and 3 compared with Group 2 and 4 (p < 0.05). CLSM showed the dead-to-live ratio in Groups 1-4 were 1.15±0.12, 0.53±0.13, 1.10±0.24 and 0.63±0.10, respectively (Group 1,3 > 2,4, p < 0.05). SEM revealed Groups 1 and 3 had scattered biofilm whereas Group 2 and 4 had confluent biofilm. Micro-CT showed the enamel lesion depths (µm) were 98±9, 126±7, 103±6 and 128±7 for Group 1 to 4, respectively (Group 1,3 < 2,4, p < 0.05). SEM revealed oriented and ordered enamel prismatic patterns in Group 1 and 3, not in Group 2 and 4. XRD showed the reflections of hydroxyapatite in Groups 1 and 3 were sharper than Groups 2 and 4. CONCLUSION: SDF pretreatment enhances the preventive effect of GIC on proximal enamel surface on neighboring tooth through inhibiting cariogenic biofilm, reducing enamel demineralization and promoting enamel remineralization. CLINICAL SIGNIFICANCE: SDF pretreatment of GIC restorations can help prevent caries on neighboring teeth, particular for patients with high caries risk.

The use of silver diamine fluoride to prevent/treat enamel carious lesions: a narrative review.

This comprehensive literature review examines the use of silver diamine fluoride (SDF) for the prevention and treatment of enamel carious lesions. SDF has been approved by different international drug associations as a caries-preventing agent to be used on deep carious lesions (dentin). However, SDF can cause staining of exposed tooth structures. Furthermore, the effect of SDF on the bond of adhesives to the tooth structure is still being determined. This review explores various studies on the use of SDF to treat enamel carious lesions, highlighting its effectiveness and preventive action. The literature suggests that SDF inhibits bacterial growth, promotes remineralization, and does not negatively affect adhesive retentions. Potassium iodide (KI) or glutathione (GSH) can reduce staining and discoloration. However, the reviewed studies have limitations. Further research, including well-designed clinical trials, is necessary to validate the findings and evaluate the long-term implications of SDF treatment. Conclusion: Despite the above-mentioned limitations, SDF shows potential as a therapy for enamel caries prevention, remineralization, and use as an adjuvant to other dental treatments, warranting further investigation and the refinement of application methods.

Drug delivery and antibiofilm efficacy of nano silver fluoride sustained release orthodontic elastomerics against Streptococcus mutans.

We aimed to investigate the chemical and physical properties of nano silver fluoride sustained release orthodontic elastomerics (NSF-RE) and determine their antimicrobial and antibiofilm formation activities against Streptococcus mutans. Orthodontic elastomerics were dip-coated with NSF solution in ethyl cellulose (EC) and polyethylene glycol 6000 (PEG). The studied groups included NSF (no EC/PEG), NSF-E (EC), NSF-EP1 (EC:PEG, 4:1), and NSF-EP2 (EC:PEG, 2:1). The cumulative release of silver nanoparticles (AgNPs) and fluoride, along with the compatibility of the tensile force with orthodontic brackets, was evaluated. The antimicrobial activity was evaluated using an agar diffusion test. The inhibition of biofilm formation was evaluated using colony-forming units (CFUs), biofilm thickness, and the live/dead cell ratio. NSF-RE containing EC sustained the release of AgNPs and fluoride for > 7 days. Tensile forces were not significantly different among the groups. The inhibition zone was 2.64- and 1.31-fold larger with NSF-EP2 than that with NSF and NSF-E, respectively. NSF-EP2 was the most effective in inhibiting biofilm formation with significant reductions in CFUs, biofilm thickness, and live/dead cell ratio by 57, 86, and 96%, respectively, as compared to those in the control group. Overall, sustained release of AgNPs and fluoride by NSF-RE provides antimicrobial and antibiofilm effects against S. mutans.

Rational design and construction of direct Z-scheme ternary heterojunction photocatalyst AgBr/CoWO4/Ag for efficient environmental remediation.

The indiscriminate discharge of micropollutants (e.g., dyes, antibiotics, industrial additives, etc.) represents a significant risk to human health, and the removal of these substances from water bodies has become a prominent area of research within the field of environmental remediation. A simple hydrothermal-precipitation-photoreduction method was employed to synthesize novel Z-scheme heterojunction photocatalysts of AgBr/CoWO4/Ag. The catalysts demonstrated remarkable degradation capabilities with regard to a range of micropollutants present in wastewater. Of the catalysts tested, 5AgBr/CoWO4/Ag exhibited the highest degradation rates, reaching 98.58% for Rhodamine B, 86.82% for tetracycline hydrochloride, and 95.60% for 2-mercaptobenzothiazole within 60 min. In particular, the reaction kinetic rate of 5AgBr/CoWO4/Ag towards Rhodamine B degradation (k2 = 0.26278 L mg-1·min-1) is 9 times that of AgBr (k2 = 0.02953 L mg-1·min-1) and 113 times that of CoWO4 (k2 = 0.00233 L mg-1·min-1), which serves to highlight the exceptional photocatalytic activity of the material. The experimental data and subsequent analysis indicated that the enhanced photocatalytic performance can be attributed to two factors: firstly, the electron mediation by Ag nanoparticles leading to improved charge separation efficiency, and secondly, the formation of Z-scheme heterojunctions between AgBr and CoWO4. The cyclic tests provided confirmation of the excellent stability and recyclability of the AgBr/CoWO4/Ag photocatalysts. It is anticipated that this study will facilitate the development of novel methods for the degradation of refractory micropollutants and provide insights into environmental remediation, thereby contributing to the sustainable development of society.

Analysis of therapeutic effect of silver-based dressings on chronic wound healing.

Chronic wounds are susceptible to bacterial infections and at high risk of developing antibiotic-resistant bacterial infections. Silver is an antimicrobial by targeting almost all types of bacteria in chronic wounds to reduce the bacterial load in the infected area and further facilitate the healing process. This study focused on exploring whether silver-based dressings were superior to non-silver dressings in the treatment of chronic wounds. PubMed, Web of Science and Embase were comprehensively searched from inception to March 2024 for randomized clinical trials and observational studies. The endpoints in terms of wound healing rate, complete healing time, reduction on wound surface area and wound infection rate were analysed using Review Manager 5.4 software. A total of 15 studies involving 5046 patients were eventually included. The results showed that compared with patients provided with non-silver dressings, patients provided with silver-based dressings had higher wound healing rate (OR: 1.43, 95% CI: 1.10-1.85, p = 0.008), shorter complete healing time (MD: -0.96, 95% CI: -1.08 ~ -0.85, p < 0.00001) and lower wound infection rate (OR: 0.56, 95% CI: 0.40-0.79, p = 0.001); no significant difference in the reduction on wound surface area (MD: 12.41, 95% CI: -19.59-44.40, p = 0.45) was found. These findings suggested that the silver-based dressings were able to enhance chronic wound healing rate, shorten the complete healing time and reduce wound infection rate, but had no significant improvement in the reduction on wound surface area. Large-scale and rigorous studies are required to confirm the beneficial effects of silver-based dressings on chronic wound healing.

Harnessing the power of Neobacillus niacini AUMC-B524 for silver oxide nanoparticle synthesis: optimization, characterization, and bioactivity exploration.

BACKGROUND: Biotechnology provides a cost-effective way to produce nanomaterials such as silver oxide nanoparticles (Ag2ONPs), which have emerged as versatile entities with diverse applications. This study investigated the ability of endophytic bacteria to biosynthesize Ag2ONPs. RESULTS: A novel endophytic bacterial strain, Neobacillus niacini AUMC-B524, was isolated from Lycium shawii Roem. & Schult leaves and used to synthesize Ag2ONPS extracellularly. Plackett-Burman design and response surface approach was carried out to optimize the biosynthesis of Ag2ONPs (Bio-Ag2ONPs). Comprehensive characterization techniques, including UV-vis spectral analysis, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction, dynamic light scattering analysis, Raman microscopy, and energy dispersive X-ray analysis, confirmed the precise composition of the Ag2ONPS. Bio-Ag2ONPs were effective against multidrug-resistant wound pathogens, with minimum inhibitory concentrations (1-25 µg mL-1). Notably, Bio-Ag2ONPs demonstrated no cytotoxic effects on human skin fibroblasts (HSF) in vitro, while effectively suppressing the proliferation of human epidermoid skin carcinoma (A-431) cells, inducing apoptosis and modulating the key apoptotic genes including Bcl-2 associated X protein (Bax), B-cell lymphoma 2 (Bcl-2), Caspase-3 (Cas-3), and guardian of the genome (P53). CONCLUSIONS: These findings highlight the therapeutic potential of Bio-Ag2ONPs synthesized by endophytic N. niacini AUMC-B524, underscoring their antibacterial efficacy, anticancer activity, and biocompatibility, paving the way for novel therapeutic strategies.