sodium-hypochlorite and sodium-thiosulfate

To compare in vitro intracanal bacterial reduction using nickel-titanium rotary instruments with and without apical enlargement.. Thirty-eight palatal roots of maxillary molar teeth, with mature apices were subdivided according to lengths and then randomly assigned to two experimental and one control groups. The roots were sterilized and then reinfected with Enterococcus faecalis, which served as a bacteriological marker. All roots in the experimental groups were prepared in a step-down sequence with engine-driven GT rotary files at 350 rpm. In experimental group A (n = 16) additional apical enlargement to ISO size 35 was performed. In group B (n = 16) a serial step-back technique was followed with no apical enlargement. This was combined in groups A and B with irrigation with NaOCl and EDTA. In the control group (group C, n = 6) irrigation only was carried out, with no mechanical preparation. Samples were then taken from the root canals to determine the numbers of remaining bacteria.. In groups A and B, 15 (94%) and 13 (81%) specimens were rendered bacteria-free, respectively. In the control group C none of the specimens were bacteria-free. There was a significant difference (P < 0.001) in the antibacterial effects of experimental and control regimens. There was, however, no significant difference (P = 0.276) between the preparation methods used in the experimental groups.. There was no significant difference in intracanal bacterial reduction when Ni-Ti GT rotary preparation with NaOCl and EDTA irrigation was used with or without apical enlargement preparation technique. It may therefore not be necessary to remove dentine in the apical part of the root canal when a suitable coronal taper is achieved to allow satisfactory irrigation of the root canal system with antimicrobial agents.

Topics: Analysis of Variance; Chelating Agents; Colony Count, Microbial; Confidence Intervals; Dental Alloys; Dental Pulp Cavity; Dentin; Disinfectants; Edetic Acid; Enterococcus faecalis; Equipment Design; Humans; Linear Models; Logistic Models; Microscopy, Electron, Scanning; Molar; Nickel; Pilot Projects; Root Canal Irrigants; Root Canal Preparation; Sodium Hypochlorite; Statistics as Topic; Thiosulfates; Titanium; Tooth Apex

This study aimed to identify possible products resulting from chemical interactions between calcium hypochlorite (Ca[OCl]. The 5.25% Ca(OCl). The interactions between Ca(OCl). The orange-brown precipitate occurs due to the chlorination of guanidine nitrogens, and the milky-white precipitate is due to the partial neutralization of the oxidizing agent. The release of chlorine gas occurs due to the low pH of the mixture, which results in the rapid formation and decomposition of chlorine. In this context, an intermediate rinsed with distilled water, saline solution, and ethanol between Ca(OCl)

Topics: Chemical Precipitation; Chlorhexidine; Chlorine; Citric Acid; Edetic Acid; Ethanol; Oxidants; Root Canal Irrigants; Saline Solution; Sodium Chloride; Sodium Hypochlorite; Water

This study evaluated the efficacy of sodium thiosulphate (ST) as an intermediate irrigant between sodium hypochlorite (NaOCl) and chlorhexidine (CHX) to avoid the formation of the brown-coloured precipitate. The in vitro experiment used microtubes to test the mixture of 2.5% NaOCl, 2% CHX and 5% ST solutions, varying their order and time of addition. In the ex vivo experiment, 10 bovine teeth were divided into two groups according to the intermediate irrigant used: distilled water (control) and 5% ST (experimental). Colour change occurred in all microtubes after interaction between solutions. While the precipitate was not observed in the experimental group, it was seen in all specimens of the control group. The 5% ST was able to prevent the formation of the brown-coloured precipitate in the ex vivo experiment, whereas it only prevented its in vitro formation when the waiting time for adding CHX was 10, 15 and 20 min.

Topics: Animals; Cattle; Chemical Precipitation; Chlorhexidine; Root Canal Irrigants; Sodium Hypochlorite; Thiosulfates

To evaluate intermediate treatments between sodium hypochlorite and chlorhexidine gluconate irrigations for the prevention of a toxic brown precipitate in root canal therapy.. Thirty-nine premolars were irrigated with 6% sodium hypochlorite and divided into either: No intermediate treatment; Dry paper points; three different irrigations with 17% ethylenediaminetetraacetic acid, deionized water, or 5% sodium thiosulfate. 2% chlorhexidine gluconate was the final irrigant in all groups. Sectioned teeth were analyzed for brown precipitate intensity and area using stereomicroscopy and components related to para-chloroaniline using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS).. Stereomicroscopy showed that 5% STS significantly reduced brown precipitate intensity and area as compared with no intermediate irrigation (p < .05, Chi-square, generalized linear model, and Tukey's multiple comparison tests). Utilizing ToF-SIMS, 5% sodium thiosulfate was most effective in reducing the components representing para-chloroaniline and chlorhexidine gluconate.. The 5% sodium thiosulfate was most effective among other intermediate treatments, assessed by stereomicroscopy and ToF-SIMS.

Topics: Chemical Precipitation; Root Canal Irrigants; Sodium Hypochlorite

This study aims to evaluate the ability of sodium thiosulfate (STS) to neutralize the adverse effect of sodium hypochlorite (NaOCl) on dentin micro-hardness.. Fifty single-rooted teeth were longitudinally sectioned. The samples divided into a control and four sample groups (n = 20). All the samples were immersed in different solutions as follows, Control: Normal saline for 15 min, G1and G2: 2.5% NaOCl for 15 min, G3: 2.5% NaOCl for 15 min, followed by 5% STS for 10 min, G4: Normal saline for 15 min followed by 5% STS for 10 min. All groups except G1 incubated for one week before the test. The micro-hardness of samples was measured. Data were analyzed using the Kruskal-Wallis test for pairwise comparisons. A p value < 0.05 was considered significant.. All groups showed a significant decrease in the micro-hardness value compared with the control group. NaOCl for one week (G2) reduced the micro-hardness of dentine compared with samples, tested immediately after immersion in NaOCl (G1) (p < 0.05). NaOCl alone (G2) or treated with STS (G3) resulted in a significant decrease in micro-hardness compared with the STS group (G4) (p < 0.05).. STS as a neutralizing agent could not prevent the dentin micro-hardness downturn caused by NaOCl.

Topics: Dentin; Hardness; Humans; Root Canal Irrigants; Sodium Hypochlorite; Thiosulfates

The effect of irrigation time on the antimicrobial efficacy of an apical negative pressure irrigation system was examined in vitro, followed by validation of the antimicrobial effect in vivo using the identified optimal irrigation time.. For the in vitro experiment, 44 extracted premolars were decoronated, instrumented, autoclaved and inoculated with Enterococcus faecalis (ATCC 29212) for 21 days. Four teeth were used as positive control, without irrigation. Each of the remaining 40 teeth was irrigated with 2.5% NaOCl, delivered via the EndoVac MacroCannula for 10 s, and subsequently via the EndoVac MicroCannula for 15, 30, 45, 60 or 90 s per canal, respectively (N = 8). After irrigation, microbial samples were collected, transferred to BHI broth and incubated for counting of bacterial colony forming units (CFUs). Based on the in vitro results, 8.25% NaOCl was delivered via the EndoVac MicroCannula for 60 s, during root canal treatment of 20 human subjects presented with apical periodontitis. Microbial samples retrieved in vivo prior to canal instrumentation (S0), after chemomechanical debridement (S1) and after irrigation with EndoVac (S2) were cultured in an anaerobic chamber for 7 days for CFU evaluation.. Compared with the control, irrigation significantly reduced bacterial populations (p < .05). Irrigation delivery via the EndoVac demonstrated improved antibacterial efficacy with increased irrigation time (p < .05). Samples retrieved from canals after NaOCl delivery in vivo with the EndoVac for 60 s were all culture-negative.. Microbial elimination may be achieved with 8.25% NaOCl delivered via the EndoVac apical negative pressure irrigation device for 60 s.. With the use of the EndoVac apical negative pressure irrigant delivery system, optimal elimination of the intracanal bacterial load can only be achieved when sodium hypochlorite is delivered via the MicroCannula for at least 60 s per canal.

Topics: Alloys; Anti-Infective Agents; Bacterial Load; Bicuspid; Debridement; Dental Pulp Cavity; Disinfection; Enterococcus faecalis; Humans; Periapical Periodontitis; Pressure; Root Canal Irrigants; Root Canal Preparation; Root Canal Therapy; Sodium Hypochlorite; Thiosulfates; Time Factors

An analytical method for determining the presence and levels of residual active ingredients found in neutralized suspensions of phenolic and quaternary ammonium salt-based antimicrobial products was developed using solid-phase extraction in combination with LC-tandem MS. A single-laboratory validation of the method was performed at three concentration levels for the quaternary ammonium compounds (also referred to as benzalkonium chlorides or BACs) and the phenols in the presence of letheen broth neutralizer at 2.5 and 2.75 μg/mL, respectively, as well as at dilutions of 1:10 and 1:100 in those concentrations. The method's lowest LODs were 0.005 μg/g for BACs and 0.006 μg/g for phenols. The average recovery of the fortified samples for both active ingredients ranged between 80 and 124%, and RSDs were generally <20%. In a related study, the effectiveness of letheen broth with and without sodium thiosulfate was evaluated as a neutralizer for sodium hypochlorite. The results showed that letheen broth without sodium thiosulfate neutralizes chlorine concentrations up to 60 ppm, and that 200 μg sodium thiosulfate are required to neutralize a 72 ppm concentrated chlorine solution in letheen broth.

Topics: Anti-Infective Agents; Benzalkonium Compounds; Biphenyl Compounds; Chromatography, Ion Exchange; Culture Media; Dichlorophen; Lipids; Phenols; Sodium Hypochlorite; Tandem Mass Spectrometry; Thiosulfates

The aim of this study was to evaluate the efficacy of sodium thiosulfate (Na2S2O3) for restoring adhesion to pulp chamber dentin treated with sodium hypochlorite (NaOCl) and EDTA.. Sixty-three crowns of bovine incisors were cut to expose the dentin pulp chamber. The specimens were polished and randomly distributed into 9 groups (n = 7) according to the following protocols used: 0.9% sodium chloride for 30 minutes (negative control), 5.25% NaOCl for 30 minutes, 17% EDTA for 3 minutes, and 5.25% NaOCl for 1 minute (positive control). The other groups, after treatments with NaOCl and EDTA, were immersed in 0.5% or 5% Na2S2O3 for 1, 5, and 10 minutes or just immersed in an inert solution for 10 minutes (0.9% sodium chloride). After drying the specimens, Scotchbond Multi-Purpose (3M ESPE, St Paul, MN) was applied to the pulp chamber dentin followed by Filtek Z250 composite (3M ESPE). Six rectangular slabs were obtained from each specimen, and the dentin/resin interface was tested by using a universal testing machine. The resulting data were submitted to 1-way analysis of variance and the Duncan test (P = .05).. There was a significant decrease in bond strength regarding NaOCl and EDTA (P < .05). When 5% Na2S2O3 was used for 10 minutes, the bond strength was found to be statistically equal to the negative control and higher than the positive control (P < .05).. The use of Na2S2O3 can significantly increase the bond strength of composite resin to NaOCl/EDTA-treated dentin, allowing adhesive restorations to be immediately applied after endodontic treatment.

Topics: Acid Etching, Dental; Adhesives; Animals; Antioxidants; Cattle; Composite Resins; Dental Bonding; Dental Pulp Cavity; Dental Stress Analysis; Dentin; Dentin-Bonding Agents; Edetic Acid; Incisor; Root Canal Irrigants; Sodium Hypochlorite; Thiosulfates

Studies for decontamination of antineoplastic compounds have been conducted for decades. Nevertheless, recent studies indicate the contamination of work place in hospitals, and the exposure of workers. In this study, to develop an effective cleaning method for contaminated environments, the degradation efficacies of antineoplastic compounds by reagents were evaluated.. The degradation efficacies of various combinations of three reagents (sodium hypochlorite, sodium thiosulfate, and sodium hydroxide) were evaluated with four antineoplastic compounds (cyclophosphamide, epirubicin, cisplatin, and carboplatin). The residues of antineoplastic compounds were measured with high-performance liquid chromatography.. Of the three reagents, sodium hypochlorite was the most effective to all antineoplastic compounds used in this study. Although sodium hypochlorite degraded 86.6% of cyclophosphamide, it degraded other three antineoplastic compounds completely. The combination with sodium hypochlorite and sodium thiosulfate degraded only 3.3% of cyclophosphamide, since sodium thiosulfate inhibited the degradation ability of sodium hypochlorite. Similarly, the combinations used in all three reagents failed to degrade cyclophosphamide.. Although three of four antineoplastic compounds were degraded successfully, any combinations of three reagents could not degrade cyclophosphamide completely. However, the addition of sodium thiosulfate which inhibits the corrosion of metal by sodium hypochlorite is essential for daily cleaning. Therefore, the evaluation of reaction time before the addition of sodium thiosulfate may be required. We will continue to investigate the reagents for degradation.

Topics: Antineoplastic Agents; Chemistry, Pharmaceutical; Chromatography, High Pressure Liquid; Drug Contamination; Humans; Indicators and Reagents; Sodium Hydroxide; Sodium Hypochlorite; Thiosulfates

To establish a refined model of artificially infected root canals and confirm its suitability as a sensitive ex vivo method to assess the efficacy of disinfecting agents. Disinfection was evaluated using sodium hypochlorite (NaOCl), either blocked or unblocked by sodium thiosulphate, and a recently promoted method of disinfection, the antibacterial photodynamic therapy (PDT).. The roots of bovine incisors were sectioned into three parts, the canals of coronal and middle regions were filled with a suspension of Enterococcus faecalis and the apical region with culture medium. After 7 days, coronal sections were disinfected using NaOCl (0.5%, 1.0% and 3.0% for 30, 60 and 600 s) or a system for photoactivated chemotherapy (PACT; Cumdente, Tübingen, Germany) for antibacterial PDT. Apical sections served as sterile controls and middle sections as bacterial growth controls. In half of the NaOCl-treated specimens, disinfection was arrested. Dentine chips from biopsies at different depths from the central canal towards the periphery were plated and assessed for colony-forming units (CFU). Disinfection was considered biologically relevant if the reduction of CFU was at least three log10 orders of magnitude.. Colony-forming units of 10³ - 10⁴ in growth controls indicated effective artificial infection. A biologically relevant reduction of CFU was accomplished with unblocked NaOCl, but not after blocking with NaOCl nor with PDT.. The system reliably detected disinfection of the root canal and dentinal tubules and proved suitable for ex vivo testing of root canal disinfection. The effect of NaOCl depended on the duration of impact. Under the present experimental conditions, the antibacterial PDT system did not achieve sufficient disinfection.

Topics: Animals; Bacterial Load; Cattle; Chelating Agents; Dental Disinfectants; Dental Pulp Cavity; Dentin; Disinfection; Dose-Response Relationship, Drug; Enterococcus faecalis; Gram-Positive Bacterial Infections; Low-Level Light Therapy; Microscopy, Electron, Scanning; Photochemotherapy; Photosensitizing Agents; Root Canal Irrigants; Sodium Hypochlorite; Thiosulfates; Tissue Culture Techniques; Tolonium Chloride

Compare the efficacy of the cleaning technique usually employed in our healthcare facility to eliminate environmental contamination with cyclophosphamide with that of the Surface Safe commercial kit.. This is a three-step evaluative and comparative study involving: (i) the voluntary contamination of the surface of a hood with a pre-established quantity of cyclophosphamide (20,000,000 ng), (ii) the cleaning of the work surface of the hood using a cleaning technique usually employed in our healthcare facility or that of the product Surface Safe, and (iii) the quantification of cyclophosphamide detected on the work surface. The usual cleaning technique involves the use of a mixture of 0.05% chlorhexidine and 70% ethyl alcohol to clean surfaces, whereas the product Surface Safe involves a combined two-step sodium hypochlorite and sodium thiosulfate wash.. The median concentrations of cyclophosphamide detected after the use of the usual technique and the product Surface Safe came to 165 ng cm(-2) (40-570) and 65 ng cm(-2) (57-110), respectively. The results obtained showed an average 99.5% efficacy in reducing the quantity of cyclophosphamide (ng) detected on the work surface for each of the two techniques that were evaluated.. The study demonstrates that reducing the residual concentration of cyclophosphamide on work surfaces to levels lower than 1 ng cm(-2) remains difficult despite the use of cleaning techniques with a high percentage of efficacy. It stressed the importance of combining two successive cleaning techniques to maximally restrict the residual concentration of hazardous drugs and suggests the use of a combination of sodium hypochlorite and sodium thiosulfate to best reduce environmental contamination levels.

Topics: Chlorhexidine; Cyclophosphamide; Decontamination; Environmental Monitoring; Environmental Pollution; Equipment Contamination; Ethanol; Hazardous Substances; Humans; Mutagens; Occupational Exposure; Pharmacy Service, Hospital; Pilot Projects; Sodium Hypochlorite; Thiosulfates; Workplace

The effect of pulsed low-direct-current (DC) electric treatment on the viability of Vibrio parahaemolyticus in artificial seawater and 3.0% (w/v) NaCl solution was studied as a function of available chlorine (AC) concentration. The amount of AC generated during the DC electric treatment increased in proportion to the amount of passed DC. The survival fraction of V. parahaemolyticus cells decreased depending on AC concentration. When the generated AC components were completely reduced in the presence of sufficient sodium thiosulfate, no inactivation of V. parahaemolyticus in the NaCl solution was observed during the DC electric treatment. Based on the AC concentration, the inactivation efficacies of the DC electric treatment of the seawater and NaCl solution were approximately 4-fold and 30-fold that of the exogenous addition of sodium hypochlorite, respectively. Fluorometric analysis using 2-[6-(4'-hydroxy)phenoxy-3H-xanthen-3-on-9-yl]benzoic acid showed that the generation of highly reactive radical species such as hydroxyl radical in the seawater and NaCl solution occurred during the DC electric treatment. The amount of generated radical species depended on the amount of passed DC. It is concluded that pulsed low-DC electric treatment of saline solutions exerts superior inactivation efficacy against V. parahaemolyticus to sodium hypochlorite owing to the generation of radical species.

Topics: Electricity; Food Handling; Hydroxyl Radical; Reactive Oxygen Species; Seafood; Seawater; Sodium Chloride; Sodium Hypochlorite; Thiosulfates; Vibrio parahaemolyticus

In this paper, the quenching of hydrogen peroxide by catalase, sodium hypochlorite, sodium thiosulfate and sodium sulfite, prior to UFC testing, was investigated. Sodium hypochlorite, sodium thiosulfate and sodium sulfite were found to be unsuitable for quenching H2O2 residuals because the procedures are time-consuming and complicated in that they require potentially multiple measurements of the peroxide and chlorine residuals. In contrast, quenching of peroxide with catalase is a simple procedure. Catalase doses of less than 0.2 mg/L were found to have no impact on DBP (TTHM, HAA and aldehyde) formation in the UFC test, and the time that was needed to quench 100 mg/L peroxide (room temperature, pH 8.3) was less than 10 min. In addition, peroxide was found to react with DPD reagents that are used to measure chlorine residuals, a phenomenon that may lead to falsely high chlorine residuals in the UFC test.

Topics: Catalase; Chlorine Compounds; Hydrogen Peroxide; Oxidants; Sodium Hypochlorite; Sulfites; Thiosulfates; Waste Disposal, Fluid; Water Pollution; Water Purification

The effects of chlorine at varying pH, culture media and incubation temperatures on one type and two wild type strains of Yersinia enterocolitica were studied. Exposure to 1 and 5 mg 1(-1) did not diminish viability, even after prolonged exposure. A level of 10 mg 1(-1) was required to achieve a 5-log reduction in 120 s for the type strain and 80 s for the wild strains. There was an increase of more than 30% in the rate of disinfection with a 10 degrees C rise, a remarkable increase in antimicrobial activity at pH 5-log reduction in 20 s, as well as marked neutralization of the effect in the presence of 0.1% peptone. Younger cells were more susceptible than older ones, and those from liquid medium more resistant than those from solid medium. Incubation temperature of a 24-h inoculum failed to show any influence. Lastly, there was a noteworthy demand for free chlorine by bacterial biomass, with agreement of the curve depicting the drop in free chlorine in the presence of inoculum with biphasic kinetics of survival curves.

Topics: Cell Survival; Hydrogen-Ion Concentration; Osmolar Concentration; Peptones; Sodium Hypochlorite; Species Specificity; Temperature; Thiosulfates; Yersinia enterocolitica