ABSTRACT
Aim:
The purpose of this systematic review was to evaluate the superiority of sodium hypochlorite (NaOCl) liquid or NaOCl gel in disinfecting root canals.
Methods:
Online electronic ...databases such as PubMed-MEDLINE, Scopus, and Embase were explored for suitable studies. In this evaluation, papers were deemed eligible for the data extraction if they included in vitro experiments using NaOCl liquid or NaOCl gel for canal irrigation and its influence on the smear layer, as well as their elimination of the bacteria from the root canal. The review was registered in International Prospective Register of Systematic Reviews with registration number CRD420223441126.
Results:
One hundred and sixty-one articles were found after initial screening and four articles were included for qualitative synthesis. Overall risk of bias was “high.” Two studies did not show significant variations among 2.5% NaOCl solution and gel.
Conclusion:
As per rigorous investigation done, NaOCl solution proved more efficient against Enterococcus faecalis than its gel form. More research is needed to determine the best effective NaOCl type, concentration, duration, and treatment regimens.
The aim was to investigate the influence of endodontic irrigation solutions and protocols on the micro-tensile bond strength (μTBS) to dentin using an etch-and-rinse (ER) or self-etch (SE) adhesive ...approach. Eighty extracted human molars were ground to dentin. After pretreating for 27 min (21 min-3 min-3 min) with five different endodontic irrigation protocols (Group 1: NaOCl-EDTA-NaOCl; Group 2: NaOCl-NaOCl-EDTA; Group 3: NaOCl-NaCl-NaOCl; Group 4: Dual Rinse-Dual Rinse-Dual Rinse; Group 5: NaCl-NaCl-NaCl), an ER (Optibond FL, Kerr) or a SE (Clearfil SE Bond, Kuraray) adhesive system was applied. After light-curing, composite build-ups were made and cut into dentin-composite sticks. μTBS and failure modes were analyzed. Nonparametric statistical analyses (α = 0.05) were performed for comparison of the five groups within each type of adhesive as well as between the two adhesive systems used. The use of an ER instead of a SE adhesive system resulted in significantly higher μTBS for all irrigation protocols except for group 1 (NaOCl-EDTA-NaOCl) and 2 (NaOCl-NaOCl-EDTA). A statistical difference between the five different endodontic irrigation protocols was only found within the SE adhesive group, where group 1 (NaOCl-EDTA-NaOCl) achieved highest values. The use of an ER adhesive system cancels out the effect of the endodontic irrigation solution. The highest μTBS was achieved when using a NaOCl-EDTA-NaOCl-irrigation protocol in combination with Clearfil SE Bond, which shows that the selection of the endodontic irrigation should match the corresponding SE adhesive system.
Cypripedium guttatum is a highly restricted terrestrial orchid that faces increasing endangerment owing to its habitat destruction and illegal collection. Compared to epiphytic orchids, terrestrial ...orchids such as C. guttatum have harder seed coats and more demanding in vitro germination conditions. This study aimed to develop an effective in vitro propagation system for C. guttatum to aid in its conservation. Seeds from mature capsules were subjected to various conditions, including sterilization using 1% sodium hypochlorite (NaOCl) and different light conditions, culture media, hormones, and organic supplements, to assess germination and early seedling development in vitro. Sterilization with 1% NaOCl significantly improved the germination rate, especially under dark conditions. Germination initiation occurred at 2 and 3 months in orchid seed sowing medium (OSM) and Murashige and Skoog (MS) medium, respectively. The addition of 1 mg/L naphthaleneacetic acid (NAA) further enhanced germination. However, the inclusion of organic supplements, such as apple and banana homogenates, in the culture medium led to substantial growth inhibition after 12 months. Notably, orchid maintenance medium (OMM) without organic additives proved to be the most suitable for seedling growth. The results of this study show that sterilization, appropriate light, and optimal NAA concentrations are beneficial for seed germination.
The reaction mechanism of ClOsub.2-mediated TEMPO oxidation was investigated by EPR spectroscopy and UV–Vis spectroscopy in the context of an alternative TEMPO sequence for cellulose fiber oxidation. ...Without the presence of a cellulosic substrate, a reversibility between TEMPO and its oxidation product, TEMPOsup.+, was displayed, with an effect of the pH and reagent molar ratios. The involvement of HOCl and Clsup.−, formed as byproducts in the oxidation mechanism, was also evidenced. Trapping HOCl partly inhibits the reaction, whereas adding methylglucoside, a cellulose model compound, inhibits the reversibility of the reaction to TEMPO.
To evaluate the bacteria debridement efficacy of two generations of sonic root canal irrigant activation systems: EndoActivator (Dentsply Sirona), the first generation, and SmartLite Pro ...EndoActivator, the second generation.
Instrumented, autoclaved, single-rooted human premolars were inoculated with Enterococcus faecalis (ATCC-29212) for 21 days. The bacteria biofilm-containing teeth were randomly divided into 5 groups (N=8): Group 1: Syringe-side-vented needle (S-N) delivery of saline for 1 min; Group 2: S-N delivery of 2% NaOCl for 1 min; Group 3: S-N delivery of 2% NaOCl for 5 min; Group 4: EndoActivator activation of 2% NaOCl for 1 min; Group 5: SmartLite Pro EndoActivator activation of 2% NaOCl for 1 min. The teeth were evaluated for bacterial reduction using CFU counts, and the percentages of dead bacteria within the dentinal tubules using confocal laser scanning microscopy.
Activation of NaOCl with EndoActivator or SmartLite Pro EndoActivator significantly reduced the overall intracanal bacterial load, compared with S-N irrigant delivery (P<0.05), with no significant difference between the two agitation devices (P>0.05). Nevertheless, S-N delivery of 2% NaOCl for 5 min produced better bacteria debridement than either sonic agitation system. Different degrees of bacteria kill were identified in the coronal-middle portions and apical portion of the canal space.
Delivery time of NaOCl affects the efficacy of bacteria disinfection. Activation for 1 min with the EndoActivator or SmartLite Pro EndoActivator demonstrated comparable canal wall biofilm and intracanal bacteria reduction efficacy when 2% NaOCl was used as irrigant for disinfecting E. faecalis in single-rooted teeth.
Although the sonic root canal irrigant activation devices investigated do not completely eliminate live bacteria biofilms from the canal space, they help reduce bacteria load during irrigant activation.
Ricin is a highly toxic protein, capable of inhibiting protein synthesis within cells, and is produced from the beans of the Ricinus communis (castor bean) plant. Numerous recent incidents involving ...ricin have occurred, many in the form of mailed letters resulting in both building and mail sorting facility contamination. The goal of this study was to assess the decontamination efficacy of several commercial off-the-shelf (COTS) cleaners and decontaminants (solutions of sodium hypochlorite bleach, quaternary ammonium, sodium percarbonate, peracetic acid, and hydrogen peroxide) against a crude preparation of ricin toxin. The ricin was inoculated onto four common building materials (pine wood, drywall joint tape, countertop laminate, and industrial carpet), and the decontaminants were applied to the test coupons using a handheld sprayer. Decontamination efficacy was quantified using an in-vitro cytotoxicity assay to measure the quantity of bioactive ricin toxin extracted from test coupons as compared to the corresponding positive controls (not sprayed with decontaminant). Results showed that decontamination efficacy varied by decontaminant and substrate material, and that efficacy generally improved as the number of spray applications or contact time increased. The solutions of 0.45% peracetic acid and the 20,000-parts per million (ppm) sodium hypochlorite provided the overall best decontamination efficacy. The 0.45% peracetic acid solution achieved 97.8 to 99.8% reduction with a 30-min contact time.
The interaction of sodium hypochlorite (NaOCl) and chlorhexidine gluconate (CHX) produces an orange-brown precipitate. The present study evaluated the influence of distilled water (H
O) in different ...irrigation protocols designed to prevent the formation of precipitate with NaOCl and CHX. Fifty canine teeth were instrumented and split longitudinally. The canal was examined with a stereomicroscope and photographed by canal-thirds. The tooth halves were repositioned and distributed randomly into five groups, according to the final irrigation protocol (n = 10): G1 (control)-Ethylenediaminetetraacetic acid (EDTA) + NaOCl + CHX, conventional irrigation (CI); G2-EDTA + NaOCl + CHX, activated with passive ultrasonic irrigation (PUI); G3-EDTA (PUI) + NaOCl (PUI) + H
O (CI) + CHX (PUI); G4-EDTA + NaOCl + H
O + CHX (PUI); G5-EDTA (PUI) + NaOCl (PUI) + H
O (continuous ultrasonic irrigation CUI) + CHX (PUI). The specimens were evaluated with a stereomicroscope and scanning electron microscope (SEM). Energy dispersive x-ray spectroscopy analysis was performed to identify the elemental profile of the irrigated canal walls. The images were scored according to the extensiveness of precipitate. Data were analyzed (Kruskal-Wallis test, α = 5%). Under the stereomicroscope, G1 had significantly higher scores than all the other groups in all canal-thirds (p < .05). All four experimental groups showed similar scores (p > .05). There were no significant differences in precipitate formation among root-thirds in intragroup analysis (p > .05). Upon SEM examination, overall, only G5 had lower scores than G1 (p < .05). Analysis by canal-thirds showed no significant difference among groups and among canal-thirds in the intragroup analysis (p > .05). G1 showed high Cl peaks. In-between irrigation with H
O activated by CUI is effective in preventing precipitate formation during canal debridement with NaOCl and CHX. RESEARCH HIGHLIGHTS: Continuous ultrasonic irrigation with distilled water was capable to prevent the precipitate formation. The precipitate can be classified as a chemical smear layer.
Castor (Ricinus communis) is a non-edible seed cultivated for the highly-valued oil extracted from its seed. Uneven germination and seedling emergence is a frequent problem for the establishment of ...castor fields. This study tested the hypothesis that castor can be selected for fast germination using the method of single-seed selection. Two-hundred castor seeds cv. BRS Energia were incubated at 22 °C in germination paper, and the 10 seeds that germinated faster were selected, planted, and cultivated to produce seeds. The harvested seeds were subjected to an additional cycle of single-seed selection for fast germination, and the gemination ability was sequentially tested along 8 months after harvest. It was observed that freshly harvested seeds have reduced germination ability at suboptimal temperature (22 °C), but they germinated better when exposed to near-optimal temperature (30 °C) or the germination ability gradually increased over time. The selection for fast-germinating seeds unintentionally selected seeds that germinate quickly in response to sodium hypochlorite (NaClO) which was used for disinfection, and that sensibility was effectively transferred to the descendants. Other highly saline substances (NaCl and KCl) elicited germination on the previously-selected NaClO-sensitive genotypes. The study was not conclusive if two cycles of single-seed selection obtained substantial improvement of the germination ability of freshly harvested seeds under suboptimal temperature.
•Castor seed germination is highly uneven.•Single-seed selection was effective for improving germination of castor seed.•Castor germination ability is very low on freshly harvested seeds.•Castor seed germination ability increases as the seed is stored.•Castor genotypes were unintentionally selected for germination elicited by NaClO.
A new coronavirus (SARS-CoV-2) abruptly emerged in Wuhan, China, in 2019 and rapidly spread globally to cause the COVID-19 pandemic.
To examine the anti-SARS-CoV-2 activity of the potent disinfectant ...Cleverin, the major disinfecting component of which is chlorine dioxide (ClO2); and to compare the results with that of sodium hypochlorite in the presence or absence of 0.5% or 1.0% foetal bovine serum (FBS).
Concentrated SARS-CoV-2 viruses were treated with various concentrations of ClO2 and sodium hypochlorite and 50% tissue culture infective dose was calcurated to evaluate the antiviral activity of each chemical.
When SARS-CoV-2 viruses were treated with 0.8 ppm ClO2 or sodium hypochlorite, viral titre was decreased only by 1 log10 TCID50/mL in 3 min. However, the viral titre was decreased by more than 4 log10 TCID50/mL when treated with 80 ppm of each chemical for 10 s regardless of presence or absence of FBS. It should be emphasized that treatment with 24 ppm of ClO2 inactivated more than 99.99% SARS-CoV-2 within 10 s or 99.99% SARS-CoV-2 in 1 min in the presence of 0.5% or 1.0% FBS, respectively. By contrast, 24 ppm of sodium hypochlorite inactivated only 99% or 90% SARS-CoV-2 in 3 min under similar conditions. Notably, except for ClO2, the other components of Cleverin such as sodium chlorite, decaglycerol monolaurate, and silicone showed no significant antiviral activity.
Altogether, the results strongly suggest that although ClO2 and sodium hypochlorite are strong antiviral agents in absence of organic matter but in presence of organic matter, ClO2 is a more potent antiviral agent against SARS-CoV-2 than sodium hypochlorite.
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