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Dental Materials : Official Publication... Jun 2024Root canal irrigation endodontic solutions have effects on the chemistry of dentin. Infrared spectroscopy is a non-destructive chemical characterization method where the... (Review)
Review
BACKGROUND
Root canal irrigation endodontic solutions have effects on the chemistry of dentin. Infrared spectroscopy is a non-destructive chemical characterization method where the strength of absorption often correlates with mineral or organic composition.
OBJECTIVES
To survey effects of commonly used irrigation solutions on the composition of root dentin as detected by widely-available Fourier transform infrared spectroscopy (FTIR) methods.
METHODS
Electronic databases were searched for articles published between 1983 to 2023. After risk of bias assessments (OHAT), studies were grouped according to effects per irrigation solution. Inclusion criteria comprised in vitro studies that used extracted human or bovine teeth, treated by irrigation solutions characterized using FTIR spectroscopy and presenting spectral data. Publications that did not share FTIR spectra were excluded.
RESULTS
A wide range of concentrations, durations, and methodologies have been tested but only 30 out of 3452 studies met our inclusion criteria. Different FTIR methods were used with the Attenuated Total Reflection (ATR) variant being the most common (21 studies). Investigated solutions included sodium hypochlorite (NaOCl), ethylenediaminetetraacetic-acid (EDTA), 1-hydroxyethylidene-1-1-diphosphonic-acid (HEDP), peracetic-acid (PAA), glycolic-acid (GA), and citric-acid (CA) though most focused on NaOCl and EDTA. All solutions had detectable effects on the FTIR signature of dentin. NaOCl mainly affects the organic signatures, revealing reduced amide/phosphate ratios with increasing concentrations. EDTA mainly effects the inorganic component, increasing with time and concentration, yet glycolic acid has stronger effects than EDTA on dentin. Beyond the type of irrigant and dentin exposure durations, concentration and protocol of application had strong effects. There is a lack of studies comparing similar irrigants under conditions that mimic clinical scenarios analyzing bulk sample because FTIR of powder dentin differs from bulk measurements.
SIGNIFICANCE
The ideal root-canal irrigant should combine local disinfection properties with minimal compositional effects on healthy dentin. FTIR methods appear reliable to identify important changes in root dentin chemical composition. Such information can help understand when endodontic irrigation might lead to root degradation or possibly contribute to long term failures such as vertical fractures. Awareness of chemical damage from irrigation procedures may help clinicians select procedures that reduce deleterious effects on the root canal structures.
PubMed: 38825554
DOI: 10.1016/j.dental.2024.05.014 -
Journal of Hazardous Materials Aug 2024Peracetic acid (PAA) as emerging oxidant in advanced oxidation processes (AOPs) has attracted widespread attention in purifying water pollution. In this research, the...
Peracetic acid (PAA) as emerging oxidant in advanced oxidation processes (AOPs) has attracted widespread attention in purifying water pollution. In this research, the removal of target contaminant (sulfamethoxazole, SMX) was investigated through PAA activation by a facile catalyst (Co@C), and the active sites of catalyst were identified as sp-C, O, and Co by correlation analysis. Especially, different pH adjustment strategies were designed, including System A (adjusting pH after adding PAA) and System B (adjusting pH before adding PAA), to investigate the impact of oxidant acidity and alkalinity on solution microenvironment as well as effect and mechanism of pollutant removal. The results showed that HO· and CHC(O)OO· dominated in System A, while Co(IV)O was also observed in System B. Both systems showed optimal SMX degradation (98 %). However, System A exhibited excellent water quality tolerance (efficiency > 78 %), superior sustained catalyst activation (efficiency > 80 % in 40 h), less ion leaching (41 μg L), and lower products toxicity. Moreover, the pH of solution after reaction in System B was intensely acidic, requiring costly pH adjustments for discharge. This study unveils the strategy of adjusting pH after adding PAA is preferable for water purification, enriching the emerging research of PAA-based AOPs for the remediation of environments.
PubMed: 38823106
DOI: 10.1016/j.jhazmat.2024.134674 -
Environmental Research Sep 2024In this study, electrochemistry was used to enhance the advanced oxidation of Fe(Ⅱ)/PAA (EC/Fe(Ⅱ)/PAA) to disintegrate waste activated sludge, and its performance...
In this study, electrochemistry was used to enhance the advanced oxidation of Fe(Ⅱ)/PAA (EC/Fe(Ⅱ)/PAA) to disintegrate waste activated sludge, and its performance and mechanism was compared with those of EC, PAA, EC/PAA and Fe(Ⅱ)/PAA. Results showed that the EC/Fe(Ⅱ)/PAA process effectively improved sludge disintegration and the concentrations of soluble chemical oxygen demand, polysaccharides and nucleic acids increased by 62.85%, 41.15% and 12.21%, respectively, compared to the Fe(Ⅱ)/PAA process. Mechanism analysis showed that the main active species produced in the EC/Fe(Ⅱ)/PAA process were •OH, R-O• and FeO. During the reaction process, sludge flocs were disrupted and particle size was reduced by the combined effects of active species oxidation, electrochemical oxidation and PAA oxidation. Furthermore, extracellular polymeric substances (EPS) was degraded, the conversion of TB-EPS to LB-EPS and S-EPS was promoted and the total protein and polysaccharide contents of EPS were increased. After sludge cells were disrupted, intracellular substances were released, causing an increase in nucleic acids, humic acids and fulvic acids in the supernatant, and resulting in sludge reduction. EC effectively accelerated the conversion of Fe(Ⅲ) to Fe(Ⅱ), which was conducive to the activation of PAA, while also enhancing the disintegration of EPS and sludge cells. This study provided an effective approach for the release of organic matter, offering significant benefits in sludge resource utilization.
Topics: Sewage; Waste Disposal, Fluid; Oxidation-Reduction; Electrochemical Techniques; Iron; Biological Oxygen Demand Analysis
PubMed: 38815721
DOI: 10.1016/j.envres.2024.119268 -
Proceedings of the National Academy of... Jun 2024Peracetic acid (PAA) is emerging as a versatile agent for generating long-lived and selectively oxidative organic radicals (R-O). Currently, the conventional transition...
Peracetic acid (PAA) is emerging as a versatile agent for generating long-lived and selectively oxidative organic radicals (R-O). Currently, the conventional transition metal-based activation strategies still suffer from metal ion leaching, undesirable by-products formation, and uncontrolled reactive species production. To address these challenges, we present a method employing BiOI with a unique electron structure as a PAA activator, thereby predominantly generating CHC(O)O radicals. The specificity of CHC(O)O generation ensured the superior performance of the BiOI/PAA system across a wide pH range (2.0 to 11.0), even in the presence of complex interfering substances such as humic acids, chloride ions, bicarbonate ions, and real-world water matrices. Unlike conventional catalytic oxidative methods, the BiOI/PAA system degrades sulfonamides without producing any toxic by-products. Our findings demonstrate the advantages of CHC(O)O in water decontamination and pave the way for the development of eco-friendly water decontaminations based on organic peroxides.
PubMed: 38805289
DOI: 10.1073/pnas.2403544121 -
Materials (Basel, Switzerland) May 2024Natural fiber composites have been extensively studied for structural applications, with recent exploration into their potential for various uses. This study...
Natural fiber composites have been extensively studied for structural applications, with recent exploration into their potential for various uses. This study investigates the impact of chemical treatments on the properties of Brazilian jute woven fabric/polyester resin composites. Sodium hydroxide, hydrogen peroxide, and peracetic acid were utilized to treat the jute fabrics, followed by resin transfer molding (RTM) to form the composites. Evaluation included water absorption, flexural strength, tensile strength, and short-beam strength. The alkaline treatment induced changes in the chemical composition of the fibers' surface. Chemical treatments resulted in increased flexural and short-beam strength of the composites, with no significant alterations in tensile properties. The hydrogen peroxide treatment exhibited lower water absorption, suggesting its potential as a viable option for enhancing the performance of these composites.
PubMed: 38793387
DOI: 10.3390/ma17102320 -
Microorganisms May 2024The aim of this study was to test the inactivation of viruses on germ carriers of different types of wood using a disinfectant in order to assess the biosafety of wood...
The aim of this study was to test the inactivation of viruses on germ carriers of different types of wood using a disinfectant in order to assess the biosafety of wood as a building material in animal husbandry. The laboratory disinfectant efficacy tests were based on German testing guidelines and current European standards. Five different types of wood germ carriers, i.e., spruce (), pine (), poplar ( sp.), beech () and Douglas fir (), were inoculated with enveloped or non-enveloped viruses and then treated with one of three different disinfectants. The results revealed that intact, fine-sawn timber with a low roughness depth can be effectively inactivated. Peracetic acid proved to be the most effective disinfectant across all tests. Regardless of the pathogen and the type of wood, a concentration of 0.1% of the pure substance at a temperature of 10 °C and an exposure time of one hour can be recommended. At a temperature of -10 °C, a concentration of 0.75% is recommended. The basic chemicals formic acid and glutaraldehyde demonstrated only limited effectiveness overall. The synergistic effects of various wood components on the inactivation of viruses offer potential for further investigation. Disinfectant tests should also be conclusively verified in field trials to ensure that the results from standardised laboratory tests can be transferred to real stable conditions.
PubMed: 38792848
DOI: 10.3390/microorganisms12051019 -
Foods (Basel, Switzerland) May 2024This study investigated the antimicrobial effects of lactic acid (LA) (3%) and peracetic acid (PA) (300 ppm) on tilapia fillets () by fogging (15 min) or by immersion (2...
This study investigated the antimicrobial effects of lactic acid (LA) (3%) and peracetic acid (PA) (300 ppm) on tilapia fillets () by fogging (15 min) or by immersion (2 s) in a pool of (NEWP 0022, ATCC 25922, and a field-isolated strain), (ATCC 25923 and a field-isolated strain), and Typhimurium (ATCC 13311 and ATCC 14028), as well as the effects on the physicochemical characteristics of the fillets. Fogging was effective and the best application method to control . Typhimurium regardless of the acid used, promoting reductions of 1.66 and 1.23 log CFU/g with PA and LA, respectively. Regarding , there were significant reductions higher than 1 log CFU/g, regardless of the treatment or acid used. For , only immersion in PA showed no significant difference ( < 0.05). For other treatments, significant reductions of 0.98, 1.51, and 1.17 log CFU/g were observed for nebulized PA, immersion, and LA fogging, respectively. Concerning the pH of the samples, neither of the acids used differed from the control. However, treatments with LA, and fogging with PA, reduced the pH compared to immersion in PA. As for color parameters, L* and a* values showed changes regardless of the acid or method used, resulting in an improved perception of fillet quality. These results indicate that fogging and immersion are alternatives for reducing Typhimurium, , and in tilapia fillets.
PubMed: 38790821
DOI: 10.3390/foods13101520 -
Journal of Hazardous Materials Jul 2024In this study, cobalt molybdate (CoMoO) activated peracetic acid (PAA) was developed for water purification. CoMoO/PAA system could remove 95% SMX with...
In this study, cobalt molybdate (CoMoO) activated peracetic acid (PAA) was developed for water purification. CoMoO/PAA system could remove 95% SMX with pseudo-first-order reaction rate constant of 0.15410 min, which was much higher than CoFeO/PAA, FeMoO/PAA, and CoMoO/persulfate systems. CoMoO/PAA system follows a non-radical species pathway dominated by the high-valent cobalt (Co(IV)), and CHC(O)OO shows a minor contribution to decontamination. Density functional theory (DFT) calculation indicates that the generation of Co(IV) is thermodynamically more favorable than CHC(O)OO generation. The abundant Co(IV) generation was attributed to the special structure of CoMoO and effect of molybdenum on redox cycle of Co(II)/Co(III). DFT calculation showed that the atoms of SMX with higher ƒ and ƒ values are the main attack sites, which are in accordance with the results of degradation byproducts. CoMoO/PAA system can effectively reduce biological toxicity after the reaction. Benefiting from the selective of Co(IV) and CHC(O)OO, the established CoMoO/PAA system exhibits excellent anti-interference capacity and satisfactory decontamination performance under actual water conditions. Furthermore, the system was capable of good potential practical application for efficient removal of various organics and favorable reuse. Overall, this study provides a new strategy by CoMoO activated PAA for decontamination with high efficiency, high selectivity and favorable anti-interference.
PubMed: 38772113
DOI: 10.1016/j.jhazmat.2024.134639 -
Brazilian Journal of Microbiology :... May 2024This study aimed to evaluate the ability of biofilm formation by L. monocytogenes from the meat processing industry environment, as well as the use of different...
Biofilm formation by Listeria monocytogenes from the meat processing industry environment and the use of different combinations of detergents, sanitizers, and UV-A radiation to control this microorganism in planktonic and sessile forms.
This study aimed to evaluate the ability of biofilm formation by L. monocytogenes from the meat processing industry environment, as well as the use of different combinations of detergents, sanitizers, and UV-A radiation in the control of this microorganism in the planktonic and sessile forms. Four L. monocytogenes isolates were evaluated and showed moderate ability to form biofilm, as well as carried genes related to biofilm production (agrB, agrD, prfA, actA, cheA, cheY, flaA, sigB), and genes related to tolerance to sanitizers (lde and qacH). The biofilm-forming isolates of L. monocytogenes were susceptible to quaternary ammonium compound (QAC) and peracetic acid (PA) in planktonic form, with minimum inhibitory concentrations of 125 and 75 ppm, respectively, for contact times of 10 and 5 min. These concentrations are lower than those recommended by the manufacturers, which are at least 200 and 300 ppm for QAC and PA, respectively. Biofilms of L. monocytogenes formed from a pool of isolates on stainless steel and polyurethane coupons were subjected to 14 treatments involving acid and enzymatic detergents, QAC and PA sanitizers, and UV-A radiation at varying concentrations and contact times. All treatments reduced L. monocytogenes counts in the biofilm, indicating that the tested detergents, sanitizers, and UV-A radiation exhibited antimicrobial activity against biofilms on both surface types. Notably, the biofilm formed on polyurethane showed greater tolerance to the evaluated compounds than the biofilm on stainless steel, likely due to the material's surface facilitating faster microbial colonization and the development of a more complex structure, as observed by scanning electron microscopy. Listeria monocytogenes isolates from the meat processing industry carry genes associated with biofilm production and can form biofilms on both stainless steel and polyurethane surfaces, which may contribute to their persistence within meat processing lines. Despite carrying sanitizer tolerance genes, QAC and PA effectively controlled these microorganisms in their planktonic form. However, combinations of detergent (AC and ENZ) with sanitizers (QAC and PA) at minimum concentrations of 125 ppm and 300 ppm, respectively, were the most effective.
PubMed: 38767749
DOI: 10.1007/s42770-024-01361-7 -
Environmental Research Jul 2024In this study, biochar derived from chestnut shells was synthesized through pyrolysis at varying temperatures from 300 °C to 900 °C. The study unveiled that the...
In this study, biochar derived from chestnut shells was synthesized through pyrolysis at varying temperatures from 300 °C to 900 °C. The study unveiled that the pyrolysis temperature is pivotal in defining the physical and chemical attributes of biochar, notably its adsorption capabilities and its role in activating peracetic acid (PAA) for the efficient removal of acetaminophen (APAP) from aquatic environments. Notably, the biochar processed at 900 °C, referred to as CN900, demonstrated an exceptional adsorption efficiency of 55.8 mg g, significantly outperforming its counterparts produced at lower temperatures (CN300, CN500, and CN700). This enhanced performance of CN900 is attributed to its increased surface area, improved micro-porosity, and a greater abundance of oxygen-containing functional groups, which are a consequence of the elevated pyrolysis temperature. These oxygen-rich functional groups, such as carbonyls, play a crucial role in facilitating the decomposition of the O-O bond in PAA, leading to the generation of reactive oxygen species (ROS) through electron transfer mechanisms. This investigation contributes to the development of sustainable and cost-effective materials for water purification, underscoring the potential of chestnut shell-derived biochar as an efficient adsorbent and catalyst for PAA activation, thereby offering a viable solution for environmental cleanup efforts.
Topics: Charcoal; Acetaminophen; Water Pollutants, Chemical; Pyrolysis; Peracetic Acid; Adsorption; Water Purification
PubMed: 38751000
DOI: 10.1016/j.envres.2024.119143