Silver Diamine Fluoride Protocol for Reducing Preventable Dental Hospitalisations in Victorian Children

IntroductionThis study was designed to assess whether a dental caries management protocol combining a single application of 38% silver diamine fluoride (SDF) with comprehensive oral health education will successfully divert high-risk children from dental treatment under dental general anaesthesia (DGA), arrest active caries in primary teeth, and improve parent-reported child oral health–related quality of life (OHRQoL).MethodsChildren aged 2 to 10 years, who attended two public dental agencies in Victoria, Australia, and were unable to tolerate restorative treatments in the clinic setting, elected to participate in either a 38% SDF intervention protocol or, alternatively, referral for DGA. Follow-up examinations were completed at 6 months to assess caries progression, decayed missing filled tooth index, PUFA index (pulpal involvement, ulceration, fistula, abscess), DGA referral rates, and OHRQoL (Early Childhood Oral Health Impact Scale [ECOHIS]).ResultsOf the total sample, 89.5% of children (n = 102) [mean (SD) age, 4.1 (1.0) years] with 401 active carious lesions elected to participate in the 38% SDF protocol; 10.5% (n = 12) of parents opted for referral for treatment under DGA. The proportion of active caries subsequently arrested at follow-up (number of arrested lesions/number of lesions treated) was 0.78 (95% CI, 0.69 to 0.87). There was an 88% reduction in referrals for DGA in eligible children over the 6-month period. The 38% SDF intervention group showed a significant improvement in ECOHIS scores at follow-up (P < .001).DiscussionAdoption of the 38% SDF intervention protocol resulted in a significant reduction in the rate of preventable dental hospitalisations. Most parents opted against referral for DGA. Parent-reported OHRQoL for children improved significantly.     

Silver Diamine Fluoride: Extending the spectrum of Preventive Dentistry,a literature review

Dental caries continues to be a severe oral health problem despite a decrease in its prevalence over the past few decades. The contemporary philosophy of caries management has shifted from the traditional approach to a newer medical one, that frequently includes utilization of fluoridated and antimicrobial agents. Among these different agents, Silver Diamine Fluoride (SDF)¹ has gained significant recognition. Dr Nishino and Dr Yamaga in Japan, pioneered its application to arrest caries. It is an alkaline, colourless solution composed of diamine-silver and fluoride ions having silver's antibacterial and fluoride's remineralising property. It has been used successfully to arrest and prevent caries in deciduous and permanent teeth, prevent recurrence of secondary caries and treat dentinal hypersensitivity. No adverse systemic effects due to SDF have been noted although black discolouration following its application has raised concerns. When used wisely it is an effective, sustainable and inexpensive option for children with high caries risk, for individuals who cannot endure conventional modalities of restorative treatment and those with special health-care needs. The current review is an insight into the clinical significance and application of SDF based on published literature.     

Multivariate optimization of mebeverine analysis using molecularly imprinted polymer electrochemical sensor based on silver nanoparticles

Thin film of a moleculary imprinted polymer (MIP) based on electropolymerization method with sensitive and selective binding sites for mebeverine (MEB) was developed. This film was cast on pencil graphite electrode (PGE) by electrochemical polymerization in solution of pyrrole (PY) and template MEB via cyclic voltammetry scans and further electrodeposition of silver nanoparticles (AgNPs). Several parameters controlling the performance of the silver nano particles MIP pencil graphite electrode (AgNPs-MIP-PGE) including concentration of PY(mM) concentration of mebeverine (mM), number of cycles in electropolymerization, scan rate of CV process (mV. s^?1), deposition time of AgNPs on to the MIP surface (s), stirring rate of loading solution (rpm), electrode loading time (min), pH of Britton–Robinson Buffer (BRB) solution were examined and optimized using multivariate optimization methods such as Plackett–Burman design (PBD) and central composite design (CCD). Two dynamic linear ranges of concentration for the MIP sensor were obtained as. 1 × 10 ^?8 to 1 × 10 ^?6 and 1 × 10 ^?5 to1 × 10^?3 M with the limit of detection (LOD) of 8.6 × 10 ^?9M (S/N = 3). The proposed method was successfully intended for the determination of MEB in real samples (serum, capsule). The sensor was showed highly reproducible response (RSD 1.1%) to MEB concentration.     

Nannochloropsis Extract–Mediated Synthesis of Biogenic Silver Nanoparticles,Characterization and In Vitro Assessment of Antimicrobial,Antioxidant and Cytotoxic Activities

Objective: To investigate the biogenic synthesis of silver nanoparticles (AgNPs) using partially purified ethylacetate extract of Nannochloropsis sp. hexane (EAENH) fraction of microalga. Methods: The green synthesis ofAgNPs was confirmed with UV-Vis spectrum which shows the surface plasmon resonance (SPR) at 421 nm. FourierTransform Infrared Spectra (FTIR) presented the involvement of functional groups like carboxyl groups of fatty acids,tetraterpenoids of xanthophylls, hydroxyl groups of polyphenols, carbonyl and amide linkage of proteins in the AgNPsynthesis. Gas Chromatography-Mass Spectrometry analysis (GCMS) revealed that phytochemicals like octadecanoicacid and hexadecanoic acid imply in capping, bioreduction, and stabilization of AgNps. Result: High-resolutionTransmission electron microscope (HRTEM), Dynamic light scattering (DLS), X-ray diffraction (XRD) and EDXanalysis showed the crystalline form of the AgNPs with Z-average size 57.25 nm. The zeta potential value of -25.7mV demonstrated the negative surface charge and colloidal stability of AgNPs. The antimicrobial activity of AgNPsdisplayed effective inhibition zone against selected bacterial and fungal pathogens. In vitro, antioxidant effects wereassessed by 1,1-diphenyl-2-picryl-hydrazyl (DPPH), hydrogen peroxide and reducing power assays which revealedexcellent scavenging potential for AgNPs than the extracts. The anti-proliferative potential of biofabricated AgNPsand extracts on Human Non-small lung cancer cell line (A549) was assessed using 3–(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay with IC50 values of 15 μgmL-1 and 175 μgmL-1 respectively. Conclusion:The study reveals that the microalgae-mediated AgNPs possesses potent antimicrobial and antioxidant activity alongwith the ability to stimulate apoptosis in A-549 cell line.     

造口肉芽肿两种治疗方法疗效比较

目的观察在造口门诊用硝酸银、电灼两种治疗方法对造口肉芽肿的治疗效果。 方法造口门诊对就诊的52例造口肉芽肿患者，随机分成硝酸银组和电灼组，分别用硝酸银、电灼两种方法进行治疗，观察并分析其疗效。 结果两种治疗方法疗效比较差异无统计学意义（Z=1.646，P=0.100）。有效率回归分析电灼比硝酸银更有效。 结论两种治疗方法对造口肉芽肿均有效，可根据肉芽肿的大小、患者是否方便复诊等情况，选择适当的处理方法，以达到满意的治疗效果。     

Is the autophagy a friend or foe in the silver nanoparticles associated radiotherapy for glioma？

Malignant glioma is the most common intracranial tumor with a dismal prognosis. The radiosensitizing effect of silver nanoparticles (AgNPs) on glioma both in vitro and in vivo had been demonstrated in the previous studies of our group. However, the underlying mechanism is still unclear. Consistent with previous studies, a size and dose dependent antitumor effect and significant radiosensitivity enhancing effect of AgNPs were observed in our experiment system. We also found that cell protective autophagy could be induced by AgNPs and/or radiation, which was verified by the use of 3-MA. The mechanism through which had autophagy and the enhancement of radiosensitivity taken place was further investigated with inhibitors of ERK and JNK pathways. We demonstrated that ERK and JNK played pivotal roles in the radiosensitivity enhancement. Inhibiting ERK and JNK with U0126 and SP600125 respectively, we found that the autophagy level of the cells treated with AgNPs and radiation were attenuated. Moreover, SP600125 down-regulated the apoptosis rate of the co-treated cells significantly. Taken together, the present study would have important impact on biomedical applications of AgNPs and clinical treatment for glioma.     

Silver serum levels in burned patients treated with silver sulfadiazine and its toxicity on inflammatory cells

BackgroundSilver sulfadiazine (SSD) has been widely used in burned patients for the prevention of local infections. To be biologically active and exert antimicrobial properties, silver needs to be present in the form of silver ions (Ag¹⁺) that bind to negatively charged proteins, namely, the RNA and DNA in microorganisms. However, previous published studies conducted with SSD in the 1990s reported a high level of silver absorption through damaged skin and noted the potential cytotoxicity of Ag¹⁺ to human cells. SSD toxicity, however, had been described in cell cultures using arbitrary silver concentrations. In the present study, we determined the serum silver levels in burned patients treated with SSD and, taking into account the molar Ag¹⁺ concentrations found in these patients, we evaluated the Ag¹⁺ toxicity effects on inflammatory cells (ROS and cytokine production) in vitro.MethodsTwenty patients with an average burned body surface area of 27.68% were included in this study.ResultsPatients’ Ag¹⁺ serum levels reached up to 558 times those of the unexposed controls. Ag¹⁺ was then added to inflammatory cells in vitro at levels up to 2000 times the level of the control, and there was no effect on the viability of the cells nor on the rate of apoptosis. We observed a decrease in reactive oxygen species production by mononuclear (MN) and polymorphonuclear (PMN) cells, as well as a substantial decrease in cytokines IL-1β, IL-6, IL-8, IL-10, and TNF-α production by leukocytes (MN and PNM).ConclusionThese findings suggest that Ag¹⁺ may contribute to negative outcomes after burns, decreasing the primary defense mechanism (respiratory burst) and altering cytokine production.     

Enzymatic recovery of silver from waste radiographic film: Optimize with response surface methodology

Silver is one of the valuable materials exist freely on earth crust. Worldwide, massive demand in different purpose makes silver very valuable. On information nearly twenty percent of silver were collected from non-ferrous metallurgical industry, locally generated scrap and photographic film. The toxicity of silver directly impact on surface and ground ecosystem. So it's compulsory to treat and recycle silver from waste material. To fulfil the demand of silver from waste, an enzyme from pineapple make of use. The aim of research work is to recover the silver metal from waste X-ray film by bromelain enzyme as biocatalyst. Response surface methodology full factorial design was used to optimize three operating parameters for maximum recovery of silver. The result shows silver recovery increases with increase in protein concentration, 5.4 mg of pure silver can be recovered from 600 mg of waste X-rays film at most favourable condition of protein concentration 0.2857 mg/ml; temperature 45 °C, pH6.5 and stripping time 20 min. At same optimised parameters, papain biocatalyst shows 4.8 mg and sodium hydroxide shows 5.2 mg recovery of pure silver. The obtained silver powder (grain) having 91.12% purity and total silver recovered.     

Novel root canal sealer with dimethylaminohexadecyl methacrylate,nano-silver and nano-calcium phosphate to kill bacteria inside root dentin and increase dentin hardness

ObjectivesRoot canal re-infection and weakening of roots are two main challenges in endodontics. The objectives of the study were: (1) to develop a novel root canal sealer containing dimethylaminohexadecyl methacrylate (DMAHDM), nanoparticles of silver (NAg), and nanoparticles of amorphous calcium phosphate (NACP), and (2) to investigate the effects on the physical, anti-biofilm, remineralizing ions, and hardness of human dentin for the first time.MethodsMethacrylate-resin dual-cured root canal sealer contained 5% DMAHDM, 0.15% NAg, and NACP at 10%, 20% and 30% mass fractions. The flow, film thickness, and Ca and P ions release were investigated. The effects of NACP on radicular dentin hardness after treatment with sodium hypochlorite (NaOCL) and ethylenediaminetetraacetic acid (EDTA) were assessed. Antibacterial properties were measured against Enterococcus faecalis (E. faecalis)-impregnated dentin blocks; colony-forming units (CFU) and live/dead assays were measured.ResultsIncorporating DMAHDM, NAg and NACP did not adversely influence the flow and film thickness properties. Sealer with 30% NACP neutralized the acid and increased the solution pH (p < 0.05). Sealer containing 30% NACP regenerated dentin minerals lost due to NaOCL and EDTA treatment, and increased the dentin hardness to match that of sound dentin (p > 0.1). Incorporating 5% DMAHDM and 0.15% NAg reduced biofilm CFU of E. faecalis-impregnated dentin blocks by nearly 3 logs when compared control group (p < 0.05).SignificanceThe novel therapeutic root canal sealer with triple bioactive agents of DMAHDM, NAg and NACP neutralized acid, raised the pH, regenerated dentin minerals, increased root dentin hardness, and reduced dentin-block-impregnated biofilm CFU by 3 logs. This new sealer with highly desirable antibacterial and remineralization properties are promising to increase the success rate of endodontic therapy and strengthen the tooth root structures.