Silver Glass Research Articles

Enhancement of mineral density and mechanical properties in root caries treated with silver diammine fluoride and glass ionomer cement, with emphasis on silver ion distribution

ObjectivesThis study aimed to measure the distribution of silver ion (Ag+), mineral recovery, and nanohardness in carious lesions and comprehensively evaluate the degree of dentin restoration. MethodsSixty human teeth with root caries were randomly assigned to the control, silver diammine fluoride (SDF) [Safo], and SDF+Glass ionomer cement (GIC) treatment [Safo+Fuji] groups. Micro-computed tomography (micro-CT) was performed at five time points for each sample before/after treatment to evaluate mineral density within and around carious lesions. Three months following treatment, 12 samples were selected for synchrotron radiation X-ray fluorescence analysis to evaluate Ag+ distribution, while 15 samples were selected for nanoindentation. Data were analyzed using Dunnett's T3 test for micro-CT and Wilcoxon rank sum test with Bonferroni correction (p = 0.017) for nanoindentation. The correlation between hardness and mineral change was analyzed using the Spearman rank correlation coefficient. ResultsThe Safo and Safo+Fuji groups showed significantly higher mineral recovery rates than did the control group (p < 0.001). In the Safo group, Ag+ accumulated in the deeper layers rather than the superficial layer of caries. In the Safo+Fuji group, Ag+ was found evenly distributed throughout caries, with only a few Ag+ detected in the GIC layer. Hardness in the Safo+Fuji group was significantly higher compared with the Safo group at depths in the range of 10–50 µm. ConclusionIn the presence of GICs, SDF exhibited high remineralization capacity when diffusing throughout carious lesions over time. Combined treatment with SDF and GIC could strengthen root dentin even in the presence of caries. Clinical significanceWe found that combination treatment with SDF and GIC could increase mineral density in caries and improve the hardness of the tooth structure compared with fluoride-based agents alone. These findings might pave the way for future clinical trials to determine the therapeutic potential of nanotechnology-based restorative materials.

Does silver leach into foods exposed to silver utensils? A preliminary study with selected Indian traditional foods

Although silver is not listed as a nutrient in regulations, silver is consumed through various sources of dietary ingredients. The practice of covering certain food items with silver foils and consuming foods in a silver plate or silver glass are known. Traditional knowledge documents the number of benefits of silver to humans. Preliminary experiments were conducted to determine if silver gets leached into few traditional foods in contact with silver plate/glass were undertaken and we report the results in this article.

Comparative Evaluation of Effect of Silver Diamine Fluoride and Glass Ionomer Cement on Microhardness of Artificial Caries Lesion in Primary Teeth: An In Vitro Study.

To evaluate the remineralizing potential of glass ionomer cement (GIC) and silver diamine fluoride (SDF) on artificially induced enamel caries lesions in primary teeth. The initial baseline surface microhardness (SMH) of 40 primary teeth was tested using Vickers hardness tester, followed by the creation of artificial caries lesions by immersion in the demineralizing solution. Microhardness assessments of demineralized samples were done, and samples were randomly divided into two groups of 20 specimens: in group I, GIC was applied on demineralized enamel, and in group II, SDF was applied on demineralized enamel. Samples were subjected to pH cycling. For group I, GIC from the enamel samples was carefully removed using a surgical blade, and changes in the SMH from both groups were analyzed using Vickers microhardness test. Surface microhardness (SMH) value after pH cycling of GIC (45 ± 10.23) and SDF (47.76 ± 6.69) is statistically highly significant (<0.001) compared to the baseline SMH of both test groups. Comparison of SMH between the two groups showed statistically nonsignificant results. The remineralization potential of SDF is comparable to GIC. So, SDF can be used as a remineralizing agent for incipient enamel caries. Owing to the remineralizing ability of GIC underneath the restorations, it can be used as a therapeutic sealant for incipient enamel caries lesions, where SDF staining is not always acceptable. A 38% SDF also can be used as a remineralizing agent for incipient enamel caries lesions in situations like noncompliant patients, inaccessibility to dental care, or conditions in which esthetics is not of concern. Sunny S, Sargod SS, Bhat SS, et al. Comparative Evaluation of Effect of Silver Diamine Fluoride and Glass Ionomer Cement on Microhardness of Artificial Caries Lesion in Primary Teeth: An In Vitro Study. Int J Clin Pediatr Dent 2023;16(6):858-863.

In vitro cytocompatibility of antibacterial silver and copper-doped bioactive glasses

Fighting the formation of bacterial biofilm and simultaneously providing a bioactive environment for bone regeneration during the treatment of orthopedic infections is one of the greatest challenges in surgery. Moreover, the major global threat of rapidly increasing antimicrobial resistance calls for non-antibiotic alternatives. Bioactive glasses doped with antibacterial metal ions silver (Ag), or copper (Cu), offer a potential solution. However, an added challenge is the cytocompatibility of these antimicrobial biomaterials, which could be compromised due to the possible cytotoxic effect of the dopants.This work evaluates the cytocompatibility of two bioactive glasses, SBA2 and SBA3, either doped with Ag- (Ag-SBA2) or Cu-ions (Cu-SBA3) via ion-exchange process. The viability, proliferation, and morphology of human adipose stem cells (hASCs) were evaluated using different culture conditions: i) direct culture on glass discs, with and without pre-incubation, and ii) in medium containing glass dissolution byproducts. The release kinetics of the doped ions was evaluated in α-MEM and during cell culture. Moreover, the effect of protein adsorption on the cell response was studied by introducing a layer of fibronectin on the glass discs before direct culture with hASCs.Ag-SBA2 and Cu-SBA3 both initially inhibited the hASC viability in direct cell culture. However, cells remain viable with healthy morphology when cultured directly on pre-treated discs, or indirectly with the glass dissolution byproducts. This suggests that the cytotoxicity effect seems to arise from the contact toxicity between the cells and the material surface. Fibronectin adsorption significantly improved the cytocompatibility of Ag-SBA2, while Cu-SBA3 requires further optimization. To conclude, Ag-SBA2, through its contact toxicity, has the potential for treating early infection, without compromising long-term cytocompatibility and bioactivity. However, further optimization of the Cu-SBA3 glass is needed due to its cytotoxicity towards hASCs.

Use of Silver Diamine Fluoride and Glass Ionomer Cement (SMART-Silver Modified Atraumatic Restorative Treatment) In Pediatric Dentistry

Using silver diamine fluoride and glass ionomer cement (SMART-Silver Modified Atraumatic Restorative Treatment) in pediatric dentistry can provide a cost-effective, fast, and non-invasive approach to restoring cavities. Silver diamine fluoride is a liquid fluoride that prevents cavity-causing germs from spreading. This can be paired with glass ionomer cement to fill cavities and restore tooth structure. This therapy technique also takes less time than typical restorative treatments so that children may be treated sooner and with fewer disturbances to their daily life. Silver diamine fluoride and glass ionomer cement have become popular in pediatric dentistry for treating cavities due to their numerous benefits. This literature review comprehensively assesses the utilisation of Silver Diamine Fluoride (SDF) and Glass Ionomer Cement (GIC) in pediatric dentistry in the context of SMART-Silver Modified Atraumatic Restorative Treatment. It summarises the findings of existing literature regarding the dental procedures, treatment approaches, and materials used for the treatment, as well as the clinical outcomes, advantages, limitations, and potential applications. SMART-Silver Modified Atraumatic Restorative Treatment is an effective and minimally invasive technique that is particularly useful during the current COVID-19 pandemic, as it does not require any aerosol output while allowing dental caries to be managed without local anaesthesia in a timely, efficient, and cost-effective manner [1]. It also eliminates the need for extracting and replacing decayed teeth, thus restoring dental health and overall quality of life. In addition, the Silver-modified Atraumatic Restorative Technique is an ideal approach for managing preschool caries, as it can halt and control the progression of caries without adversely affecting any surrounding healthy tooth structures. This review establishes the utility of SMART-Silver Modified Atraumatic Restorative Treatment and underlines its effectiveness in pediatric dentistry, particularly today. Treatment and underlines its effectiveness in pediatric dentistry, particularly today. Keywords: Anaesthesia, Dentistry, Cavities, COVID-19 pandemic, Dental caries, Glass ionomer cement, Invasive, Pediatric, silver diamine fluoride, SMART-silver modified atraumatic restorative treatment

Time-dependent structural changes and hypermineralisation of artificially demineralised dentine following treatment with silver diammine fluoride and glass ionomer cement

ObjectivesThis study aimed to evaluate the change of mineral content in dentine lesions over time and examine the effectiveness of the combined treatment with silver diammine fluoride (SDF) and glass ionomer cement (GIC). MethodsSixty bovine dentine specimens were divided into 4 groups: cont, Fuji, Safo, and Safo+Fuji. The specimens were imaged and measured using microcomputed tomography (microCT) at 7 time points: pre-demineralisation, after demineralisation for two weeks, immediately after treatment, 1 week, 2 weeks, 1 month, and 3 months after treatment. The 3-month group was evaluated with a light microscope, attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy, and scanning electron microscope (SEM)/energy-dispersive X-ray spectroscopy (EDS). Data were analysed by Dunn's test and Wilcoxon signed rank test with Bonferroni correction for microCT, and Kruskal–Wallis test and two-way analysis of variance for EDS characterisation. ResultsMicroCT images showed high mineral density beneath dentine lesions in Safo+Fuji. The mineral density at 600 μm in Safo+Fuji increased significantly over time, while Safo showed an opposite trend (adjusted p<0.005). In Safo+Fuji, EDS revealed significantly high energy of fluorine (p<0.05, at 300 μm) and a tendency towards high energy of calcium (p>0.05). However, Safo+Fuji showed lower energy of silver compared to Safo (p<0.001). ATR-FTIR revealed that phosphate groups had the highest peak at a depth between 300 and 400 μm in Safo+Fuji. ConclusionsSafo+Fuji was effective in remineralising the deep lesion in dentine after one and three months, and a hypermineralisation zone generated beneath the lesion demonstrated additional benefit in this study. Clinical significanceThis long-term in vitro study showed that SDF+GIC treatment could strengthen the structure of decayed teeth when applied in the treatment of patients with advanced rampant caries.

Comparison and Advanced Antimicrobial Strategies of Silver and Copper Nanodrug-Loaded Glass Ionomer Cement against Dental Caries Microbes.

Caries lesions during cement repairs are a severe issue, and developing a unique antimicrobial restorative biomaterial can help to reduce necrotic lesion recurrence. As a result, Thymus vulgaris extract was used to biosynthesize copper nanoparticles (TVE-CuNPs) exhibiting different characteristics (TVE). Along with TVE-CuNPs, commercial silver nanoparticles (AgNPs) and metronidazole were combined with glass ionomer cement (GIC) to test its antibacterial efficacy and compressive strength. FTIR, XRD, UV-Vis spectrophotometry, and TEM were applied to characterize the TVE-CuNPs. Additionally, AgNPs and TVE-CuNPs were also combined with metronidazole and GIC. The modified GIC samples were divided into six groups, where groups 1 and 2 included conventional GIC and GIC with 1.5% metromidazole, respectively; group 3 had GIC with 0.5% TVE-CuNPs, while group 4 had 0.5% TVE-CuNPs with metronidazole in 1.5%; group 5 had GIC with 0.5% AgNPs, and group 6 had 0.5% AgNPs with metronidazole at 1.5%. An antimicrobial test was performed against Staphylococcus aureus (S. aureus) and Streptococcus mutans (S. mutans) by the disc diffusion method and the modified direct contact test (MDCT). GIC groups 4 and 6 demonstrated a greater antimicrobial efficiency against the two tested strains than the other groups. In GIC groups 4 and 6, the combination of GIC with two antimicrobial agents, 1.5% metronidazole and 0.5% TVE-CuNPs or AgNPs, enhanced the antimicrobial efficiency when compared to that of the other groups with or without a single agent. GIC group specimens combined with nanosilver and nanocopper had similar mean compressive strengths when compared to the other GIC groups. Finally, the better antimicrobial efficacy of GIC boosted by metronidazole and the tested nanoparticles against the tested strains may be relevant for the future creation of more efficient and modified restorations to reduce dental caries lesions.

The Sintering Process and Vibration Characteristics for Leadless Package Structure of Pressure Sensors

A key factor restricting the development of high-temperature pressure sensors is the packaging structure. The traditional lead package with silicone oil as the medium is difficult to meet the performance requirements in high-temperature environments. In this article, the anodic bonding method is used to bond the SOI pressure-sensitive chip and the borosilicate glass to form a vacuum chamber, which avoids the use of silicone oil. The glass hole is filled with high-temperature nanosilver paste, and the glass paste is printed on the surface. After being butted with the pins of the Kovar base, the sensor is sintered under a vacuum to realize the package of the sensor. Taking the shear strength of joint and porosity of silver paste as evaluation indexes, the optimal process parameters of silver paste and glass paste integrated sintering are studied by the Taguchi orthogonal experiment. Finite element simulation was used to analyze the vibration characteristics of the sensor, and its short-term vibration reliability was verified through vibration tests. The static output of the sensor shows that this packaging process can make it maintain good nonlinearity at high and low temperatures.

Minimally Invasive Techniques Used for Caries Management in Dentistry. A Review.

Minimally invasive techniques that use silver compounds and glass ionomer cement are suggested for caries management due to their effectiveness, simplicity, and low cost. The aim of this review is to examine the evidence supporting the use of silver compounds and glass ionomer cement in dentistry. Literature was searched using PubMed, Elsevier, EBSCO, Google scholar, AAPD and UABC's database from 1958 to 2018 with the keywords: "Silver nitrate", "silver diamine fluoride", and "glass ionomer cement". The selected studies were then fully read to prove their relevance for this review. The use of glass ionomer cement and silver compounds were shown to be effective in arresting caries. These compounds reduce cariogenic microorganisms. Their chemical properties inhibit bacterial growth while promoting remineralization. They are simpler and less time consuming than conventional restorations. They also cause less discomfort and anxiety to patients. Silver compounds were shown to stain teeth and may burn the cornea if used in high concentration. These disadvantages limit the use of silver compounds to posterior teeth and require caution when handling. Minimally invasive therapies are easy to apply, non-invasive and affordable. Further studies should be done to provide more evidence of these techniques for caries management.

Effectiveness of silver diamine fluoride and glass ionomer cement combined with fluoride varnish in arresting dental caries among intellectually disabled individuals: A randomized controlled trial.

To assess the clinical effectiveness of 38% silver diamine fluoride (SDF) in arresting dental caries when compared to combination of fluoride-containing glass ionomer cement (GIC) and fluoride varnish(FV) (5%) among intellectually disabled (ID) individuals. A randomized controlled trial was conducted among ID (n=82) individuals, in permanent posterior teeth with Nyvad score 2 and 3 (active caries) of dental caries, randomly allocated to experimental arm (38% SDF) (n=41) and control arm (GIC along with FV) (n=41). The caries arrest rate and caries preventive fraction was observed at 6-months among both groups. The caries arrest rate was 94.5% with SDF and 90.1% with GIC and FV (p=0.405).The caries preventive fraction of SDF over GIC with FV was 45%, with hazard ratio (-0.588) at 6 months (p=0.292). The binary logistic regression revealed that the Odds of arresting caries in SDF group is two times when compared to GIC group with p value=0.218 which is not significant. The present study concluded that the SDF is as clinically effective as combination of GIC and fluoride varnish in arresting caries. Further research and longer follow-up required for more conclusive results.

Evaluation of Three Borate-Bioactive Glass Compositions for Antibacterial Applications

The prevalence of cases of antibiotic resistant infections and the limited number of new antibiotics call for new strategies to prevent bacterial infections. In this study, we evaluate the effectiveness of three different compositions of bioactive glass, doped with silver as an antimicrobial agent for potential applications in preventing bacterial infections. The different glasses were formulated to dissolve and release silver at different rates enabling their use in different applications either individually or in combination to achieve a desired effect. Silver oxide (Ag2O) was incorporated into various glass formulations and antibacterial effectiveness was measured using radius of inhibition. Each silver-doped glass effectively inhibited the growth of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa with radius of inhibition correlating directly with the dissolution rate of the glass—the faster dissolving glass producing the larger radius of inhibition. Suspending particles of the silver containing glass in phosphate buffered saline or fetal calf serum, slowed the dissolution of each glass and extended the effectiveness of the silver containing glass over time (based on size of the radius of inhibition) compared to water. Potential applications of the powdered glass formulations would be to incorporate glasses with different properties into coatings or cosmetics. To investigate the feasibility of these applications, the silver-glass powder was incorporated into polycaprolactone polymer to determine the antibacterial properties of the imbedded glass powder. Based on this investigation, the silver glass formulations reported herein have potential applications in the medical device, dental, pharmaceutical and cosmetic industries.

Effect of Energy Drinks on Color Stability of Different Restorative Materials

Background: The purpose of this in vitro study was to evaluate the effect of finishing/polishing procedures on color stability of three restorative materials: Nano-hybrid resin composite (NRC), silver glass ionomer cement (SGI), and resin-modified glass ionomer cement (RMGI) exposed to different staining of energy drinks: Barbican, Bison, and Red bull.

Effect of silver diammine fluoride and glass ionomer on remineralisation of natural dentine caries

ObjectivesSilver diammine fluoride (SDF) is a caries-arresting agent for dentine lesions. This study investigated the effect of application frequency of SDF when used with glass ionomer cement (GI) for remineralising carious dentine. MethodsFreshly extracted human posterior teeth with advanced caries were used. After superficial removal of infected dentine, single (G3), double (G4), triple (G5) applications of SDF (Advantage Arrest SDF 38 %) followed by a layer of GI (GC Fuji IX GP) were compared to no treatment (negative control-G2), and GI only (G1). All teeth were stored in artificial saliva between treatments and for 2-weeks after final treatment. Micro-computed X-ray tomography (NSI) scans were obtained at each stage and analysed to plot mineral density-depth profile, lesion depth (LD) and mineral loss (ΔZ). Data was statistically analysed at a significance level of 0.05. ResultsMean LD values were 837 μm, 735 μm, 841 μm, 1008 μm, 707 μm at baseline and 785 μm, 727 μm, 712 μm, 855 μm, 639 μm after treatment for groups G1 to G5, respectively. Mean ΔZ values were 6327 vol%μm, 5995 vol%μm, 10014 vol%μm, 7192 vol%μm, 5649 vol%μm at baseline and 3686 vol%μm, 5126 vol%μm, 5539 vol%μm, 2327 vol%μm, 3218 vol%μm after treatment for groups G1 to G5, respectively. Paired t-test showed that LD and ΔZ changed significantly within all groups from baseline to treatment weeks following storage (p < 0.05) except LD in the control (p > 0.05). ANCOVA showed significant difference among groups in net lesion depth recovery and net mineral gain (p < 0.05), and G3 and G4 showed the highest mineral gains. ConclusionOne or two applications of SDF prior to placement of GI, were effective in remineralising advanced dentine lesions, while additional applications, when combined with GI, did not demonstrate additional benefit in this study. Clinical significanceThis short-term laboratory research study showed that one or two applications of SDF followed by GI coverage could remineralise advanced dentine caries in the presence of artificial saliva. This procedure carries potential in the treatment of difficult lesions where conventional restorations would require significant tooth structure removal through traumatic procedures.

Comprehensive recycling of silicon photovoltaic modules incorporating organic solvent delamination – technical, environmental and economic analyses

Photovoltaic (PV) panel manufacturing is increasing worldwide, which subsequently increases the amount of waste PV. This study proposes to recycle waste PV using organic solvent delamination followed by downstream thermal and leaching procedures. Firstly, experimental data is obtained using small commercial modules by replicating a recycling route taken from the literature. Based on the experimental results, life cycle cost analysis (LCCA) and life cycle assessment (LCA) are applied to evaluate the experimental and optimized industry scale processes. Results show that the main profitable recycling avenues are for aluminum frame and junction box removal; and that downstream processes can separate and recover all the remaining materials, but not profitably. The laboratory and high-throughput-optimized processes, considering the median costs and revenues, have a net cost of 29.00 and 3.30 USD per module, respectively. The complete recovery of materials using the proposed method is unlikely to be profitable and this may only be achievable where labor is not expensive. Alternatively, the complete recycling of waste PV could be made economically viable by reducing process time, increasing automation and/or providing financial subsidies. The environmental analysis, however, shows that the optimized process modelled here has a positive net environmental impact. The results are also compared against the cost/environmental impact of landfilling such waste. In summary, the proposed recycling route is capable of completely recovering the main materials in waste PV (aluminum frames, junction box, silver, copper tabbing, silicon, backsheet and unbroken glass) and can have a positive environmental impact, but it is not economically profitable.

Chemical and Structural Variety in Sodium Thioarsenate Glasses Studied by Neutron Diffraction and Supported by First-Principles Simulations.

Sodium-conducting sulfide glasses are promising materials for the next generation of solid-state batteries. Deep insight into the glass structure is required to ensure a functional design and tailoring of vitreous alloys for energy applications. Using pulsed neutron diffraction supported by first-principles molecular dynamics, we show a structural diversity of Na2S-As2S3 sodium thioarsenate glasses, consisting of long corner-sharing (CS) pyramidal chains CS-(AsSS2/2)k, small AspSq rings (p + q ≤ 11), mixed corner- and edge-sharing oligomers, edge-sharing (ES) dimers ES-As2S4, and isolated (ISO) pyramids ISO-AsS3, entirely or partially connected by sodium species. Polysulfide S-S bridges and structural units with homopolar As-As bonds complete the glass structure, which is basically different from structural motifs predicted by the equilibrium phase diagram. In contrast to superionic silver and sodium sulfide glasses, characterized by a significant population of isolated sulfur species Siso (0.20 < Siso/Stot < 0.28), that is, sulfur connected to only mobile cations M+ with a usual M/Siso stoichiometry of 2, poorly conducting Na2S-As2S3 alloys exhibit a modest Siso fraction of 6.2%.

Comparative Evaluation of Cention with Glass Ionomer Cement, Composite Resins and Silver Amalgam with Respect to Mechanical Strength: An in-Vitro Study

Introduction: Numerous direct filling materials are available to the modern dental practice from amalgams, GIC to modern bulk fill composites. Cention is an “alkasite” restorative. Alkasite refers to a new category of filling material, which like compomer or ormocer materials is essentially a subgroup of the composite material class. This new category utilizes an alkaline filler, capable of releasing acid-neutralizing ions. It is a tooth-colored, basic filling material for direct restorations. It is self-curing with optional additional lightcuring. It is radiopaque, and releases fluoride, calcium and hydroxide ions. As a dual-cured material it can be used as a full volume (bulk) replacement material. Hence the Aim of the study was to compare the Alkasite (Cention N) with Silver amalgam, GIC and Composite to evaluate the Compressive strength & diametral tensile strength. Materials and Method: Split molds of dimension 6 [height] x4 [diameter] was used to fabricate 15 samples of each material for testing the compressive strength and for tensile strength. And subjected under Universal Instron testing machine connected to a load measuring cell, to recorded load applied to the samples at a crosshead speed of 0.75 ± 0.25 mm/min till the samples fracture. Results: Composite and Cention N showed significantly higher strength than Silver Amalgam and Glass ionomer cement. Conclusion: Within the limitation of this study, it can be concluded that Cention N can be used as a superior alternative when compared with Silver Amalgam and Glass ionomer cement

Forensic study of mechanical properties of dental fillings after immersion in marine environment

Human identification and postmortem intervals can be difficult to estimate when corpses are found in drowning situations, and forensic odontologists can bring valuable input to forensic science investigations of this type. Studies that simulate real scenarios are crucial for providing parameters that can be used in real cases. The present study created the necessary circumstances, i.e. immersion in a marine environment, to estimate the changes in the mechanical properties (Knoop microhardness, roughness, and color) of various dental fillings (silver amalgam, composite resin, and glass ionomer cement) over different immersion periods of time (one and three months). The silver amalgam fillings showed a significant increase in surface roughness. The composite resin fillings showed statistically significant increases in surface roughness and Knoop microhardness, and the glass ionomer cement showed a significant increase in surface roughness. These results lead to the conclusion that teeth restored with silver amalgam, composite resin, and glass ionomer cement, when subjected to immersion in marine environments, produce different changes in surface roughness, Knoop microhardness, and color properties depending on the length of immersion time. These findings could help in the field of forensic science to accurately estimate immersion time of dead bodies found in marine environments.

Forensic study of mechanical properties of dental restoration after burial in mangrove environment

Conducting research in the field of forensic sciences with methodologies that simulate situations found in the day-to-day practice of a given field of expertise is relevant insofar as this approach can produce results that are as close as possible to reality. In this context, the present study provided situations based on burial in a mangrove environment to estimate the changes in the mechanical properties (Knoop microhardness, roughness and color) of dental restorations utilizing silver amalgam, composite resin and glass ionomer cement over the time of burial. The silver amalgam showed a significant increase in surface roughness and a reduction in Knoop microhardness. Composite resin showed a statistically significant increase in color variation, and the glass ionomer cement showed significant increases in color variation and Knoop microhardness. These results allowed us to conclude that teeth restored with silver amalgam, composite resin and glass ionomer cement submitted to burial in mangrove environments produce different changes in surface roughness, Knoop microhardness and color properties depending on the time of burial to which the victims were submitted. These proprieties could help the forensic sciences to estimate time intervals for burial in mangrove environments.

Synthesis and photoluminescence of silver and europium codoped germinate tellurite oxyfluoride glasses

Germinate tellurite oxyfluoride glasses of composition TeO2-GeO2-WO3-Li2O3-EuF3-AgCl (TGEUAC) were synthesized by melt quenching and heat-treated for the growth of silver nanoparticles (AgNPs). The presence of surface Plasmon resonance (SPR) absorption band of silver species with Eu3+ ions absorptions peaks for differently heat-treated glass samples were measured by the absorption spectrum. The green, red and deep- red photoluminescence intensity variation of Eu3+ ions under the influence of AgNPs has been observed. Maximum three-fold enhancement of TGEUAC-6 sample for green, red and mainly deep- red emission of Eu3+ caused by SPR of silver nanoparticles has also been observed. On the other hand, emission quenching of after long heat-treated of other samples was attributed to back energy transfer from Eu3+ ions to silver species or local field saturation. The emission intensities characterized through the CIE diagram and energy transfer mechanism of the Ag NPs to Eu3+ ions in glasses are discussed for potential application of optical devices.

Mineralogy of Sasanian Bullae

Mineralogy of Sasanian Bullae