Sodium Hypochlorite Disinfection Research Articles

Revealing microbial community composition and disinfection efficacy evaluation in wholesale pork markets through 16S rDNA sequencing

ABSTRACT This study has employed 16S rDNA analysis to elucidate the characteristics of the microbial community in the surroundings, facilities, and meat samples collected from a pork wholesale market with the aim of revealing bacterial contamination. In addition, the efficacy of sodium hypochlorite disinfectant was assessed by comparing the bacterial communities in the viable samples before and after disinfection. The bacterial abundances in meat, chopping boards, and knives were positively correlated (r > 0.95, p < .05), suggesting potential cross-contamination risks during market transactions. The species richness indices for the external transport vehicles, pork hooks, and floors were significantly different from those of the samples taken after decontamination (p < .05). Linear discriminant analysis Effect Size (LEfSe) analyses showed that Firmicutes, Proteobacteria, and Chloroflexi were significantly more abundant in the transaction period, whereas Bacteroidetes levels decreased compared to the clean-up period. NaClO disinfection altered the composition of bacterial communities.

Using ultrasonic washing combined with UV-LEDs as a novel chemical-free method to disinfect fresh ready-to-eat produce

The consumption of ready-to-eat fresh produce raises the issue of food-borne pathogen infections; thus, disinfecting ready-to-eat produce for commercial use, such as in homes and restaurants, is important to ensure food safety. Chemical sanitizers are typically used for disinfection. Ultraviolet-light emitting diodes (UV-LEDs) are a novel non-thermal disinfection technology that consumes less energy and generates less heat than traditional UV lamps, making them more appealing to consumers. In this study, we combined ultrasonic (US) washing method with UV-LEDs (US-UV-LEDs) to develop a technique for disinfecting fresh produce without using chemical sanitizers and compared its efficacy with three common household sanitizers (“84” (sodium hypochlorite) disinfectant, kettle descaler (citric acid), and vinegar (acetic acid)). In addition, we investigated the efficacy of this method in controlling pathogen numbers in the water used to wash (washing water) the produce to prevent cross-contamination between water and produce. Cherry tomatoes and lettuce were selected as produce models and Salmonella Typhimurium and Escherichia coli O157:H7 were used as the bacterial models. The results showed that US-UV-LEDs reduced the numbers of S. Typhimurium and E. coli O157:H7 on produce by 2.1–2.2 log CFU/g, consistent with the results achieved by the three household sanitizers; however, kettle descaler and vinegar had a limited effect (2.6–3.5 log CFU/mL) on residual pathogens in the washing water. Furthermore, we created washing water with low (754 mg/L) and high (1425 mg/L) chemical oxygen demand (COD) levels and determined the disinfection efficacy of “84” disinfectant and US-UV-LEDs. The results showed that US-UV-LEDs reduced the number of S. Typhimurium and E. coli O157:H7 by 2.0–2.1 and 1.8–2.1 log CFU/g under low and high COD levels, respectively, which was similar a result to that of “84” disinfectant. However, the residual pathogen numbers in the washing water were reduced to 1.4–1.9 log CFU/mL after treatment with US-UV-LED under high COD, whereas the pathogens were undetected in the washing water disinfected with “84” disinfectant. These results suggest that US-UV-LEDs have better application potential than acidic household sanitizers, but chlorine sanitizer remains the most effective disinfecting method.

Disinfectant-induced ammonia oxidation disruption in microbial N-cycling process in aquatic ecosystem after the COVID-19 outbreak

Anthropogenic activities significantly impact the elemental cycles in aquatic ecosystems, with the N-cycling playing a critical role in potential nutrient turnover and substance cycling. We hypothesized that measures to prevent COVID-19 transmission profoundly altered the nitrogen cycle in riverine ecosystems. To investigate this, we re-analyzed metagenomic data and identified 60 N-cycling genes and 21 host metagenomes from four urban reaches (one upstream city, Wuhan, and two downstream cities) along the Yangtze River. Our analyses revealed a marked decrease in the abundance of bacterial ammonia monooxygenase genes, as well as in the host, ammonia-oxidizing autotrophic Nitrosomonas, followed by a substantial recovery post-pandemic. We posited that discharge of sodium hypochlorite (NaOCl) disinfectant may be a primary factor in the reduction of N-cycling process. To test this hypothesis, we exposed pure cultures of Nitrosomonas europaea to NaOCl to explore the microbial stress response. Results indicated that NaOCl exposure rapidly compromised the cell structure and inhibited ammonia oxidation of N. europaea, likely due to oxidative stress damage and reduced expression of nitrogen metabolism-related ammonia monooxygenase. Using the functional tagging technique, we determined that NaOCl directly destroyed the ammonia monooxygenase protein and DNA structure. This study highlights the negative impacts of chlorine disinfectants on the function of aquatic ecosystems and elucidates potential mechanisms of action.

Establishment of Tissue Culture and Regeneration System in Hippophae gyantsensis Lian

Hippophae gyantsensis Lian is a pioneering tree species in Chinese forestry ecological engineering, known for its robust stress tolerance, water retention capacity, and soil improvement qualities. However, the lack of rapid nursery technology has been a significant impediment to the development of the H. gyantsensis industry. In the present study, we have successfully established a tissue culture regeneration system for H. gyantsensis. The most effective methods for seed disinfection, ensuring sterility in seedlings, were found to be 75% alcohol disinfection for 40 s and 10% sodium hypochlorite disinfection for 10 min. The best media tested for callus induction in cotyledons and hypocotyls of sterile seedlings were 1/3 MS + 0.5 mg/L KT + 0.75 mg/L NAA and 1/3 MS + 0.3 mg/L 6-BA + 1.5 mg/L IBA, respectively. As the explants, cotyledons yielded larger calli with a greater size and differentiation ability than hypocotyls. For the induction of indeterminate shoots and proliferation, the most suitable media were 1/3 MS + 0.5 mg/L IAA + 0.75 mg/L 6-BA and 1/3 MS + 1.0 mg/L 6-BA + 0.05 mg/L IBA + 0.1 mg/L KT, respectively. Lastly, the best worked rooting formulation was 1/4 MS + 0.3 mg/L IBA. This study marks a significant milestone in the establishment of a systematic tissue culture regeneration system for H. gyantsensis, which will facilitate the industrial rapid propagation of high-quality seedlings and provide the foundation for improvement through genetic transformation.

A Safer Method for Disinfection of Bacillus Calmette-Guerin-Containing Urine: A Prospective, Randomized Study.

The aim of the study was to examine whether disinfection of bacillus Calmette-Guerin-containing urine with etaprocohol® (ethanol 76.9-81.4 vol % and isopropanol as an additive) is safer than disinfection with sodium hypochlorite. In prospective research, safety and efficacy was analyzed in 5 patients in the etaprocohol® disinfection group and 5 patients in the sodium hypochlorite disinfection group. The primary endpoint was the temperature change after disinfection and the secondary endpoint was the unpleasantness of the odor caused by disinfection. Additionally, concentration of gas produced was also examined. Sensory tests were taken from staff who performed urine disinfection and the odor generated by disinfection was evaluated. As a safety protocol, post-BCG-treated urine is cultured to verify the negativity for mycobacteria. Mycobacteria were disinfected in all cases. The temperature rise following disinfection was significantly higher in the sodium hypochlorite group. The sensory test outcomes were significantly worse in the group disinfected with sodium hypochlorite. The concentration of gas generated immediately after disinfection in both groups reached the maximum value and declined quickly. Disinfection of bacillus Calmette-Guerin-containing urine with etaprocohol® was safer than disinfection with sodium hypochlorite, and an equivalent disinfection effect was achieved.

Formation and control of disinfection by-products during the trichloroisocyanuric acid disinfection in swimming pool water

The increasing demand for trichloroisocyanuric acid (TCCA) in swimming pool disinfection highlights the need to evaluate its applicability in terms of disinfection by-product (DBP) formation. Nevertheless, there is limited understanding of DBP formation and control during TCCA disinfection, particularly concerning the effects of various management parameters. This study aimed to fill this knowledge gap by comprehensively investigating DBP formation during TCCA chlorination, with a particular focus on assessing the contribution and interaction of influencing factors using Box-Behnken Design and response surface methodology. Results indicated that the concentrations of trichloroacetaldehyde, chloroform, dichloroacetic acid, trichloroacetic acid, and dichloroacetonitrile produced by TCCA disinfectant were 42.5%, 74.0%, 48.1%, 94.7% and 42.6% of those by the conventional sodium hypochlorite disinfectant, respectively. Temperature exhibited the most significant impact on chloroform formation (49%), while pH played a major role in trichloroacetaldehyde formation (44%). pH2 emerged as the primary contributor to dichloroacetic acid (90%) and trichloroacetic acid (93%) formation. The optimum water quality conditions were determined based on the minimum total DBPs (pH = 7.32, Temperature = 23.7 °C, [Cl−] = 437 mg/L). Chlorine dosage and contact time exhibited greater influence than precursor concentration on chloroform, dichloroacetonitrile, trichloroacetaldehyde, trichloroacetic acid, and total DBPs. Although the interaction between water quality parameters was weak, the interaction between disinfection operating parameters demonstrated substantial effects on DBP formation (8.56–19.06%). Furthermore, the DBP predictive models during TCCA disinfection were provided for the first time, which provides valuable insights for DBP control and early warning programs.

Corrosion Behavior of 17-4PH Martensite Stainless Steel Sprayed with Sodium Hypochlorite Disinfectant

Sodium hypochlorite (NaClO) solution, as an effective and low-cost disinfectant, is widely utilized to achieve disinfection in the industry, but introducing chloride ions causes metal material corrosion. To understand actual corrosion behavior, a comprehensive study of the corrosion behavior of 17-4PH martensitic stainless steels (MSs) by spraying NaClO disinfectant was investigated in this work. The x-ray photoelectron spectroscopy and time of flight secondary ion mass spectrometry were used to investigate the element distribution and corresponding valence states of the corrosion product on the surface of the 17-4PH MSs. Hypochlorite ions in the disinfectant decrease the atomic ratio of iron/chromium (Fe/Cr) in the corrosion product layer with the increasing corrosion time, which enhances the corrosion resistance of the studied samples. However, strongly oxidizing hypochlorite ions will promote the formation of trivalent Fe ions (Fe3+), which provokes the initiation and growth of pitting in surfaces where the existence of a Cu-riched domain is due to disinfectant migration.

Tensile Strength and Elastic Modulus of Gutta-percha Cones Disinfected with Sodium Hypochlorite at Different Immersion Times: An In Vitro Comparative Study.

The tensile strength and modulus of elasticity of gutta-percha cones can be chemically altered due to disinfectant solutions. Therefore, the aim of the present study was to compare tensile strength and elastic modulus of gutta-percha cones subjected to sodium hypochlorite (NaOCl) disinfection at different times. This in vitro and longitudinal experimental study consisted of 45 gutta-percha cones, divided equally into three groups: Group 1 (disinfection with 2.5% NaOCl), Group 2 (disinfection with 5.25% NaOCl), and control group. All groups were subdivided according to immersion times for 1, 5, and 10 minutes. Tensile strength and elastic modulus were measured with a universal testing machine. For comparing more than two independent groups, parametric analysis of variance test with Sheffe's post hoc was used and for multivariate analysis, and multivariate analysis of variance test based on Pillai's Trace was used. In all statistical analysis, a significance level P ≤ 0.05 was considered. When comparing the tensile strength of gutta-percha cones, no significant differences were observed after being immersed at 1, 5, and 10 minutes in NaOCl 2.5% (P = 0.715) and 5.25% (P = 0.585). Regarding the elastic modulus, a significant decrease (P < 0.05) was observed in those that were immersed in NaOCl 2.5% and 5.25% for 1, 5, and 10 minutes. Furthermore, increased NaOCl concentration significantly reduced the elastic modulus (P < 0.001). However, there were no significant differences in tensile strength (P > 0.05) and elastic modulus (P > 0.05), when evaluating the interaction between NaOCl concentration and time. Increasing NaOCl concentration significantly reduced the modulus of elasticity without affecting the tensile strength of gutta-percha cones, regardless of immersion time. Furthermore, the interaction of time and NaOCl concentration did not significantly affect the tensile strength and elastic modulus.

Food grade disinfectants based on hydrogen peroxide/peracetic acid and sodium hypochlorite interfere with the adhesion of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes to stainless steel of differing surface roughness

This study aimed to evaluate the potential of the bacterium Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes to adhere to stainless steel discs with differing degrees of surface roughness (Ra = 25.20–961.90 nm). Stainless steel is a material commonly used in the food industry for processing equipment, which is regularly exposed to cleaning procedures. The investigation included the commercial disinfectants hydrogen peroxide/peracetic acid and sodium hypochlorite which were evaluated for their antibacterial and anti-adhesion activity. The adhesion was assessed by the standard plate count method, while the broth microdilution method CLSI M07-A10 was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the disinfectants. Based on the MIC values, both disinfectants exerted significant inhibitory effects with MIC values for hydrogen peroxide/peracetic acid and sodium hypochlorite of 250 µg ml−1 and 500 µg ml−1, respectively. Whereas the MBC values were equal to the MIC for all bacteria except for E. coli with values 2-fold higher than the MIC. Obtained results also revealed that all tested bacteria were able to adhere to stainless steel surfaces, although differences were found for strains and surface roughness. The lowest adhesion rate of each strain was recorded on the roughest stainless steel disc at a Ra of 961.90 nm. Further, at a concentration of 1 MIC, the disinfectant sodium hypochlorite reduced initial bacterial adhesion to stainless steel surfaces to a significantly greater extent than the disinfectant hydrogen peroxide/peracetic acid. These findings are consistent with the results obtained by Scanning Electron Microscopy (SEM) analysis, which indicates the great applicability of the tested disinfectants for the control of bacterial adhesion in the food industry.

Clostridioides difficile spores tolerate disinfection with sodium hypochlorite disinfectant and remain viable within surgical scrubs and gown fabrics.

Clostridioides difficile is the most common cause of antibiotic-associated diarrhoea globally. Its spores have been implicated in the prevalence of C. difficile infection due to their resistance and transmission ability between surfaces. Currently, disinfectants such as chlorine-releasing agents (CRAs) and hydrogen peroxide are used to decontaminate and reduce the incidence of infections in clinical environments. Our previous research demonstrated the ability of C. difficile spores to survive exposure to recommended concentrations of sodium dichloroisocyanurate in liquid form and within personal protective fabrics such as surgical gowns; however, the present study examined the spore response to clinical in-use concentrations of sodium hypochlorite. Spores were exposed to a 10 min contact time of 1000, 5000 and 10 000 p.p.m. sodium hypochlorite, and spore recovery was determined. To understand whether biocide-exposed spores transmitted across clinical surfaces in vitro, biocide-exposed spores were spiked onto surgical scrubs and patient gowns and recovery was determined by a plate transfer assay. Scanning electron microscopy was used to establish if there were any morphological changes to the outer spore coat. The results revealed that viable biocide-exposed C. difficile spores can be recovered from surgical scrubs and patient gowns, with no observable changes to spore morphology, highlighting the potential of these fabrics as vectors of spore transmission. This study demonstrates that alternative strategies should be urgently sought to disinfect C. difficile spores to break the chain of transmission in clinical environments.

Occupational risk assessment of glutaraldehyde through personal air monitoring in a hospital setting.

Glutaraldehyde is a high-efficiency disinfectant that has been included in the protocols of some hospitals for controlling the spread of SARS-CoV-2, together with sodium hypochlorite and quaternary ammonium disinfectants. However, exposure has been poorly studied in workplace settings, despite the association between glutaraldehyde and respiratory diseases and skin conditions in exposed workers. This study evaluated the magnitude of exposure associated with the use of glutaraldehyde in healthcare workers across various work areas of a first level of Hospital-Based Care in Colombia. Workers were classified into similar exposure groups (SEGs) based on work areas and tasks performed, and airborne concentrations of glutaraldehyde were measured in different work areas of each SEG through direct monitoring. The 95th percentile of glutaraldehyde concentrations in all SEGs studied exceeded the TLV-C immediately after use. Cleaning workers and nurses had the highest exposures to glutaraldehyde. Results indicate that workers were overexposed and highlight the need to implement controls to reduce exposure. The high-exposure levels also raise the need to consider glutaraldehyde substitution and adequate use of personal protective equipment (PPE).

Environmental Persistence and Disinfection of Lassa Virus.

Lassa fever, caused by Lassa virus (LASV), is endemic to West Africa, where ≈300,000 illnesses and ≈5,000 deaths occur annually. LASV is primarily spread by infected multimammate rats via urine and fomites, highlighting the need to understand the environmental fate of LASV. We evaluated persistence of LASV Josiah and Sauerwald strains on surfaces, in aqueous solutions, and with sodium hypochlorite disinfection. Tested strains were more stable in deionized water (first-order rate constant [k] for Josiah, 0.23 days; for Sauerwald, k = 0.34 days) than primary influent wastewater (Josiah, k=1.3 days; Sauerwald, k = 1.9 days). Both strains had similar decay rates on high-density polyethylene (Josiah, k=4.3 days; Sauerwald, k = 2.3 days) and stainless steel (Josiah, k=5.3 days; Sauerwald, k = 2.7 days). Sodium hypochlorite was highly effective at inactivating both strains. Our findings can inform future risk assessment and management efforts for Lassa fever.

The temperature-dependent kinetics and bacteria regrowth by performic acid and sodium hypochlorite disinfection.

Sodium hypochlorite (NaOCl) has been widely used as a disinfectant in water and wastewater treatment, because of its high efficiency and low cost, whereas the bio-toxicity of its disinfection byproducts (DBPs) raised great concern. Performic acid (PFA) produces less DBPs and shows strong oxidation abilities. In this study, the effect of temperature on NaOCl and PFA disinfection as well as bacteria regrowth were evaluated. First, the inactivation of Escherichia coli, Staphylococcus aureus, and Bacillus subtilis by NaOCl and PFA at 4 and 20 °C, detected by cell cultured-based plate counting were fitted to kinetic models, and the predicted CTs were calculated. The results showed that NaOCl was more effective than PFA for E. coli and S. aureus inactivation, and the temperature was positively correlated to disinfection. Second, bacteria regrowth was evaluated at different temperatures (4 and 20 °C) of disinfection and storage. The results showed that the bacteria inactivated by NaOCl regrew prominently, especially for those inactivated at 4 and stored at 4 °C, probably through the mechanism of reactivation of viable but non-culturable (VBNC) bacteria. PFA was superior in suppressing bacteria regrowth, and it may be used as an alternate disinfectant in water treatment in cold environment.

An in Vitro Effectiveness and Evaluation of Sodium Hypochlorite for Orthodontic Buccal Tube Disinfection

Contamination of fixed orthodontic components caused by non-compliance with hygiene both during the manufacturing and packaging processes can cause cross-infection. Although the literature has demonstrated the need for sterilization or disinfection of fixed orthodontic components prior to insertion in the oral cavity, these are still not widely used in orthodontic practice. This study aims to evaluate bacterial contamination in vitro and the disinfection effect of 0.5% sodium hypochlorite on orthodontic buccal tubes. A total of 12 roth type 1 Molar buccal tubes with slots of 0.020 and still well sealed in the packaging were divided into three groups: group 1 chlorhexidine 2% (n=4), group 2 distilled water (n=4) as control, and group 3 sodium hypochlorite 0.5% (n=4) as treatment. Microbiological and biochemical tests were carried out on the three groups of first molars to detect any bacterial contamination. The buccal tube showed that it was contaminated with bacteria and then disinfected using a 2% chlorhexidine solution, distilled water and 0.5% sodium hypochlorite. Bacterial contamination was detected in all control and treatment groups. The treatment group with 0.5% sodium hypochlorite disinfection showed optimal decontamination (p 0.05) compared to the negative control group. Therefore, In vitro sodium hypochlorite 0.5% had the effect of reducing bacterial contamination of the buccal tube Roth type 1 molar with 0.020 slots.

Removal of Microcystis aeruginosa by manganese activated sodium percarbonate: Performance and role of the in-situ formed MnO2

Previous studies have found that pre-oxidation of manganese salts such as potassium permanganate and potassium manganate can remove algae in water, while existing problems such as excessive oxidation and appearance of chromaticity. In this study, our objective was to induce a Fenton-like reaction by activating sodium percarbonate (SPC) with divalent manganese (Mn(II)) to pre-oxidize algae-contaminated water. The optimal dosage of Mn(II)/SPC was determined by assessing the zeta potential of the algae and the residual Mn(II) in the solution. Moreover, we conducted a characterization of the cells post-reaction and assessed the levels of dissolved organic carbon (DOC). The disinfection by-products (DBPs) (sodium hypochlorite disinfection)of the algae-containing water subsequent to Mn(II)/SPC treatment were measured. Experiments show that Mn(II)/SPC pre-oxidation at optimal dosage acquired 88% removal of algae and less damage to the cell membrane. Moreover, the Mn(II) acted not only as a catalyst but also formed MnO2 which adsorbed onto the cell surface and facilitated sedimentation. Furthermore, this technology exhibits the capability to effectively manage algal organic matters present in water, thereby mitigating the formation of nitrogen-containing DBPs. These results highlight the potential of Mn(II)/SPC treatment for treating water contaminated with algae, thus ensuring the safety and quality of water resources.

FTIR Spectroscopic Study Of Inhibition of Chloroxylenol-Based Disinfectant Against Salmonella enterica serovar Thyphimurium Biofilm

The present work was performed to determine the impacts of commercial disinfectants against biomass, viability, and biochemical composition of Salmonella enterica serovar Thyphimurium ATCC14028 biofilm. Salmonella Thyphimurium biofilm grown in microplates was exposed to commercial disinfectants namely sodium hypochlorite, benzalkonium chloride, chloroxylenol, and sodium dodecyl-benzene sulfonate-based disinfectants. Biofilm biomass, biofilm viability, and biochemical composition of the biofilm were determined using crystal violet assay, resazurin assay and Fourier transform infrared (FTIR) spectroscopy respectively. Results demonstrated that, among four commercial disinfectants, chloroxylenol-based disinfectant showed the highest inhibition against S. Thyphimurium biofilm. It remarkably hindered biofilm biomass and biofilm viability at all tested concentrations (0.78%-25%). Half-maximal biofilm inhibitory concentration (BIC50) of chloroxylenol-based disinfectant (5.06%) was found to be the lowest among the tested disinfectants. Meanwhile, S. Thyphimurium biofilm treated with chloroxylenol-based disinfectant exhibited changes in FTIR spectral peaks associated with lipid (1460 cm-1), protein (630 cm-1, 702 cm-1, 1550 cm-1 &amp; 1650 cm-1), and nucleic acid (1080 cm-1 &amp; 1229 cm-1). The findings of the present study suggest that the inhibition of chloroxylenol-based disinfectant against S. Thyphimurium biofilm is mediated by structural changes of biofilm.

The establishment of a rapid propagation system of the petiole of Hedera helix as explants

Hedera helix is broadly distributed and cultivated globally. Hedera helix is very famous as a medicinal and ornamental plant. It is a traditional edible herb, which is beneficial to the treatment of various diseases and disorders, including cough, cold, reheumatoid arthritis and bronchial disorder. In this study, the petiole of Hedera helix was used as explants to study the effect of sodium hypochlorite disinfection time on explants, and the effects of different ratios of various plant growth regulators on callus induction and bud differentiation of explants were studied through orthogonal experiments. The optimal plant growth regulator ratio in rooting culture was also studied. The results showed that the explants were best sterilized with 2% sodium hypochlorite for 10 min. The best medium for callus induction was MS + 3.0 mg/L6-BA + 1.0 mg/L NAA + 0.1 mg/L2,4-D.The best bud differentiation medium was MS + 1.5 mg/L6-BA + 0.1 mg/L IBA + 0.5 mg/L TDZ. Significant results were achieved with rooting medium 1/2MS + 0.8 mg/L IBA. In conclusion, the objectives of the present investigation were to improve the disinfection procedure for petiole of Hedera helix explants using sterilization agents such as NaOCl with different time intervals. Moreover, the effects of different plant growth regulators on callus induction from petiole explants of Hedera helix were studied.

A study to evaluate the effectiveness of various disinfectants for extracted human teeth - A comparative study.

The aim of this study was to evaluate the effectiveness of various disinfectants for extracting human teeth. The objectives were to assess the effectiveness of 5% vinegar, 3% hydrogen peroxide, 70% alcohol, and 5.25% sodium hypochlorite for disinfection of extracted human teeth. The teeth were divided into one of the following four groups consisting of 10 teeth in each group. All teeth were immersed in separate bottles containing 10 ml of the disinfectant for 7 days at 25°C. No visible growth in the broth was considered effective disinfection. The Institutional Ethics Committee (IEC) Number is SVIEC/ON/DENT/SRP/15186, and the IEC Clearance number is SVIEC/ON/DENT/SRP/15040. Vinegar was most effective for bacterial disinfection, and 5.25% sodium hypochlorite was most effective for fungal disinfection. The result was statistically significant with Chi-square values of 0.015 and 0.057, respectively, and P < 0.001. Extracted teeth should be handled with extreme care as these are a potential source of infection. The present study documented the role of various disinfectants. Vinegar can be used as an effective disinfectant medium for extracting human teeth. Sterilisation and autoclaving are superior options while vinegar is cheap, readily available, and relatively non-toxic. All these qualities plus the fact that it has given encouraging results as an antibacterial disinfectant should necessitate its usage on a more regular basis than it is used at present.

Concentration of sodium hypochlorite disinfection in regenerative endodontic procedure: A systematic review

Objectives: To evaluate whether low concentration sodium hypochlorite (NaOCl) disinfectant protocol can achieve a sufficient amount of disinfection to provide a conducive environment for clinical and radiographic success of regenerative endodontic procedure. Materials and methods: This systematic review includes necrotic immature permanent anterior teeth below 20 years of age using triple antibiotic paste as an intra-canal medicament and autologous platelet concentrates as scaffold. The interventional group was low concentration (≤2%) NaOCl and comparator group included high concentration (&gt;2%) NaOCl as disinfectant. Cochrane risk of bias assessment 2 (RoB 2) tool was used for assessment of risk of bias. Included studies were evaluated for the absence of clinical signs and symptoms, increase in root length and apical closure on radiograph, and positive response to vitality testing. Results: After evaluation, seven studies were included. Clinical success rate was seen in 98.33% cases in low concentration (≤2%) and 95% cases in high concentration (&gt;2%) NaOCl. The radiographic success rate was 86.66% in low concentration (≤2%) and 80% in high concentration (&gt;2%) NaOCl disinfection. Positive response for vitality testing was seen in 46.66% cases in low concentration (≤2%) and 38.70% in high concentration NaOCl (&gt;2%). Conclusion: Low concentration (≤2%) NaOCl is as effective as high concentration (&gt;2%) to achieve disinfection of the root canal. However, an increased success rate is associated with the use of low concentration (≤2%) NaOCl. Response to pulp vitality is observed to be superior with low concentration (≤ 2%) NaOCl although it might be attributed to a longer follow-up period.

The Effect of Hypochlorous Acid Disinfectant on the Reproduction of Details and Surface Hardness of Type III Dental Stone.

Introduction Gypsum products have been used for many years in dentistry. They are used to make casts that are used in different dental laboratory procedures. It is considered a source of contamination because it comes in contact with blood and saliva that are found on dental impressions. Because it is difficult to make sure that every impression brought to the dental laboratory has been cleanedand because cleaning impressionsis a complicated process that can lead to problems because of the way impression materials are made, cleaning the cast has become a key part of preventing infections. For this study, we used two ways (immersion and spray) to apply a hypochlorous acid (HOCl) disinfectant solutionto type III dental stone to see how they affected the stone's surface hardness and its ability to show surface details accurately. Materials and methods A total of 100 samples of type III dental stone, 50 samples for each test, which include the reproduction of detailtest and surface hardness test, were prepared and randomly divided into five groups, 10 samples for each test group, which include group A (control), group B (immersion in 200 ppm HOCl disinfectant for five minutes), group C (spraying with 200 ppm HOCl disinfectant for five minutes), group D (immersion in 0.6% sodium hypochlorite (NaOCl) disinfectant for five minutes), and group E (spraying with 0.6% NaOCl disinfectant for five minutes). Results The results showed that all the samples had met the reproduction of detailtest requirement after disinfection with HOCl, while a significant reduction in the surface hardness of type III stone samples was also shown. Conclusion The less undesirable effects of HOCl disinfectant solution on the surface hardness of type III dental stone when compared to sodium hypochlorite, as well as the absence of adverse effects on detail reproduction, made the HOCl disinfectant solution a good choice for dentists and dental laboratory personnel for cast disinfection and contamination control.