Effectiveness of 2% peracetic acid for the disinfection of gutta-percha cones

Effective of different industrial disinfection in subzero cold-chain environment

Effective disinfection methods are crucial in the cold chain transportation process of food due to the specificity of temperature and the diversity of contaminated flora. The objective of this study was to investigate the sanitizing effect of different disinfectants on various fungi at - 20 °C to achieve accurate disinfection of diverse bacterial populations. Peracetic acid, hydrogen peroxide, and potassium bisulfate were selected as low-temperature disinfectants and were combined with antifreeze. The sanitizing effect of these cryogenic disinfectants on pathogens such as Bacillus subtilis black variant spores (ATCC9372), Staphylococcus aureus (ATCC 6538), Candida albicans (ATCC 10231), Escherichia coli (8099), and poliovirus (PV-1) was sequentially verified by bactericidal and virus inactivation experiments. After a specified time of disinfection, a neutralizing agent was used to halt the sanitizing process. The study demonstrates that different disinfectants exhibit selective effects during the low-temperature disinfection process. Peracetic acid, hydrogen peroxide, and potassium monopersulfate are suitable for the low-temperature environmental disinfection of bacterial propagules, viruses, and fungal contaminants. However, for microorganisms with strong resistance to spores, a low-temperature disinfectant based on peracetic acid should be chosen for effective disinfection treatment. Our results provide a valuable reference for selecting appropriate disinfectants to sanitize various potential pathogens in the future.

Antifungal effect of tea extracts on Candida albicans

Determining whether tea extracts are effective in removing Candida albicans (C. albicans) from dentures is of interest. This study aimed to investigate the antifungal effect of tea extracts on C. albicans. One green tea (Anji white tea, AGW) and 2 oolong teas (Tie Guan Yin, TGY; Da Hong Pao, DHP) of different concentrations were tested. C. albicans suspensions were inoculated on the plates and the numbers of colony-forming units (CFU) in the culture medium were used to screen for the optimum tea extracts. Polymethyl methacrylate (PMMA) specimens that contained C. albicans biofilms were then treated with the tea extracts and the numbers of CFU were counted. The antifungal activities of the tea extracts were not significantly correlated with their catechin concentrations. Although AGW at 10.0 mg/mL and DHP at 2.5 mg/mL significantly inhibited C. albicans in the culture medium, the extracts failed to exert inhibitory effects against C. albicans biofilms on the PMMA surfaces.

Management of Instrument Sterilization Workflow in Endodontics: A Systematic Review and Meta-Analysis

Endodontic treatment consists of different working procedures, such as the isolation of the operating field, pulp chamber access, and cleaning and shaping phases with at last the need of a three-dimensional filling of the canals. Each step requires a series of single-use or sterilizable instruments. We have performed a systematic review of different sterilization and disinfection procedures aiming at drawing up a disinfection and sterilization procedure to be used on endodontic instruments. A search on PubMed and Scopus was carried out using the following keywords: “endodontic sterilization,” “endodontic autoclave,” “decontamination dental bur,” “sterilization dental burs,” and “gutta-percha points sterilization.” Eligible articles were included in the qualitative and quantitative analysis. Results of the meta-analysis showed that the most effective method in sterilization is autoclaving. The qualitative analysis showed that the use of single-use or first-use instruments requires presterilization or sterilization procedures, and for reusable tools, attention must be paid to the removal of debris deposited on the blades, not easy to remove manually.

Gutta-percha in endodontics - A comprehensive review of material science

The complete and three-dimensional fluid tight seal of the root canal system is the final component of the endodontic triad. The long-standing and closest material which has fulfilled this criterion is gutta-percha (GP). Several materials have been tried and tested as an endodontic filling material, of which GP has been most extensively used for years and has established itself as a gold standard. In addition, it has proved itself successful with different techniques of obturation while maintaining its basic requisites. This article deals briefly with the history and evolution of GP, source, chemical composition, manufacturing, disinfection, cross-reactivity, and advancements in the material.

Disinfection and surface changes of gutta-percha cones after immersion in sodium hypochlorite solution containing surfactant

In this study, we evaluated the effectiveness of 1 and 5.25% NaOCl solutions, with or without surfactant, in disinfecting gutta-percha cones. Surface changes of the gutta-percha cones after disinfection were also assessed under scanning electron microscopy (SEM). One-hundred and eight gutta-percha cones previously contaminated with Enterococcus faecalis were left in contact for 30 s or 1 min with the following solutions (n = 12): 1% NaOCl; 1% NaOCl + 2% cetrimide; 5.25% NaOCl; 5.25% NaOCl + 2% cetrimide. Positive control group was composed by the remaining contaminated cones (n = 12), and the negative control group by noncontaminated cones (n = 12). The cones were kept in Eppendorf tubes containing Trypticase Soy Broth at 37°C for 24 hr, and then, the presence of turbidity was analyzed. Ten additional cones (n = 2) were observed under SEM to evaluate surface changes after 1 min of disinfection. The data analysis (Kruskal-Wallis test, α = 5%) demonstrated that regardless the presence of surfactant, the NaOCl solutions used were effective in the disinfection when cones were immersed for 1 min. However, at the 30-s period, only the 5.25% NaOCl solution was effective. SEM analysis demonstrated that NaOCl solutions promoted the formation of sodium chloride crystals on cones surface, less visible when the 1% NaOCl associated to surfactant was used. The addition of surfactant did not affect the disinfection capacity of NaOCl solutions. However, the surfactant has apparently inhibited the sodium chloride crystals deposition on the cones surface when associated to 1% NaOCl solution.

Analysis of Demineralized Chemical Substances for Disinfecting Gutta-percha Cones

Introduction:

The aim of the present research was to evaluate the effectiveness of 5% malic acid, 17% EDTA and 10% citric acid solutions used to disinfect gutta-percha cones contaminated by Enterococcusfaecalis (ATCC 29212).

Methods and Materials:

Two hundred and ten previously sterilized gutta-percha cones were contaminated with E. faecalis at concentration of 1.5×10⁸ CFU/mL. The cones were immersed in 5% malic acid, 17% EDTA, 10% citric acid, 1% NaOCl and 2.5% NaOCl for 1, 5 and 10 min. Then each cone was kept in Eppendorf tubes containing BHI sterile solution at 37^°C for 48 h. The presence of turbidity in BHI solution was analyzed. The results were statistically analyzed by Kruskal-Wallis test and 5% Dunn comparisons. P-value was considered statistically significant when P<0.05.

Results:

Regardless of exposure time, 1% NaOCl and 2.5% NaOCl were the most effective agents for rapid disinfection of gutta-percha cones (P<0.001). All specimens immersed in experimental demineralized solutions presented bacterial growth (P>0.05).

Conclusion:

Demineralized solutions tested were not effective for elimination of Enterococcus faecalis on the surface of gutta-percha cones.

Efficacy testing of novel chemical disinfectants on clinically relevant microbial pathogens

BACKGROUND

There has been a dramatic increase in the number of hospital-acquired infections, which is linked to the pandemic of multidrug resistance. Clinical environments provide an ideal reservoir for the growth, proliferation, and transmission of pathogenic organisms, including bacterial and yeast species. Consequently, the need for improved, effective disinfectants is of paramount importance.

METHODS

Studies were conducted to assess the efficacy of chemical disinfectants-peracetic acid and triameen-on microbial strains. Testing included the assessment of antimicrobial and antisporicidal activity of disinfection solutions performed on a range of clinical isolates that pose a high risk for patient morbidity in clinical settings.

RESULTS

Both chemical disinfectants successfully inactivated all test strains, with peracetic acid showing a greater level of antimicrobial activity. Escherichia coli proved most susceptible when assessed by the Kirby disk diffusion, suspension, and medical suspension assays with the greatest reduction in cell viability achieved. Antibiotic-resistant Enterococcus and Staphylococcus aureus strains showed greatest resistance to both disinfectants.

DISCUSSION AND CONCLUSIONS

Test chemicals show potential to act as intermediate-level disinfectants inactivating vegetative microorganisms and bacterial spores on clinically relevant strains where they show potential as a preventative measure in relation to nosocomial infections.

Antimicrobial effect of three disinfecting agents on Resilon cones and their effect on surface topography: An in vitro study

Aim:

The objective of this study was to evaluate the effectiveness of 5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and 2% peracetic acid (PAA) in disinfecting Resilon cones and to evaluate topographical changes microscopically under scanning electron microscope (SEM) after rapid chemical disinfection.

Materials and Methods:

Resilon cones were disinfected in an ultraviolet (UV) light chamber for 20 min and contaminated by immersing in a microbial suspension of Enterococcus faecalis for 30 min. The contaminated cones were then immersed in the 5.25% NaOCl, 2% CHX, and 2% PAA for 1 min, 5 min, and 10 min, separately. The cones were then incubated at 37°C in thioglycollate broth for 7 days and examined for turbidity. The samples showing turbidity were subcultured on blood agar and incubated at 37°C for 48 h. Gram staining was done to confirm that the cultured bacteria were E. faecalis. Surface changes of disinfected Resilon cones were evaluated under SEM.

Statistical Analysis Used:

The data were analyzed statistically using Kruskal-Wallis, analysis of variance (ANOVA), and Mann–Whitney U-test.

Result:

In eliminating E. faecalis, 5.25% NaOCl was most effective followed by 2% PAA and 2% CHX. Topographic examination of tested Resilon cones revealed some surface deposits after disinfection with 5.25% NaOCl and 2% CHX, whereas 2% PAA caused surface erosion.

Conclusion:

In disinfecting Resilon cones, 5.25% NaOCl is most effective followed by 2% PAA and 2% CHX.

Correlation between Enterococcus faecalis and Persistent Intraradicular Infection Compared with Primary Intraradicular Infection: A Systematic Review

INTRODUCTION

The relationship between Enterococcus faecalis and pulpal or periradicular diseases has been studied for many years; however, whether E. faecalis is correlated with persistent intraradicular infections (teeth after failed endodontic treatments) compared with primary intraradicular infections remains controversial. The objective of this systematic review was to compare the prevalence of E. faecalis in primary and persistent intraradicular infections.

METHODS

An exhaustive literature search combined with specified inclusion criteria was performed to collect all studies comparing the prevalence of E. faecalis in root canals with primary and persistent intraradicular infections. Descriptive statistics were applied first because of the high heterogeneity among studies. Subgroup analysis according to different detecting methods (culture and polymerase chain reaction) and sensitivity analysis was then applied. Meta-analysis was conducted with the help of Stata/SE 12.0 (StataCorp, College Station, TX) after excluding studies with uncertain forms of pulpal and periradicular lesions in their primary infection groups.

RESULTS

The systematic review included 10 studies covering 972 teeth. Among them, 2 studies used the culture technique, 6 studies used polymerase chain reaction, and the other 2 used both techniques. The detection rate of E. faecalis by both methods was higher in persistent infections compared with untreated chronic periapical periodontitis as primary infections. The difference was statistically significant (odds ratio = 7.247; 95% confidence interval, 4.039-13.002).

CONCLUSIONS

E. faecalis is more highly correlated with persistent intraradicular infections compared with untreated chronic periapical periodontitis.

Effect of green tea extract and mouthwash without alcohol on Candida albicans biofilm on acrylic resin

OBJECTIVE

To evaluate the effect of aqueous extract of green tea and the oral antiseptic without alcohol, on Candida albicans biofilm formation to heat-curing acrylic resin plates.

BACKGROUND

Candida is associated with oral candidiasis in poorly cleaned dentures.

MATERIAL AND METHODS

Standardised specimens of heat-cured (Conv; n = 30) or microwave-cured acrylic resin (Mw; n = 30) were obtained and divided into six groups (n = 10): G1 = Conv resin and green tea aqueous extract, G2 = Conv resin and mouthwash, G3 = control of Conv resin, G4 = Mw resin and green tea aqueous extract, G5 = Mw resin and mouthwash and G6 = control of Mw-cured resin. The specimens were contaminated with 10 ml of Sabouraud dextrose broth inoculated with 0.1 ml of standard suspension containing 1 × 10(6) cells/ml of C. albicans and incubated for 24 h at 37°C. After this period, they were immersed in the aqueous extract or in mouthwash for 15 min. The control groups were treated with sterile distilled water. Aliquots of 0.1 ml were plated on Sabouraud dextrose agar and incubated at 37°C for 24 h. The numbers of colony-forming units per test specimen (CFU/TS) were calculated, and the results statistically analysed by two-way anova and Tukey's tests (5%).

RESULTS

Statistically significant difference was observed for the aqueous extract groups (G1; 33.65%) and mouthwash (G2; 17.06%), when compared to control (G3; 100%), for Conv resin. For the Mw resin, there was significant difference between mouthwash (G5; 43.16%) and control (G6; 100%).

CONCLUSION

The aqueous extract of green tea and mouthwash led to a reduction in the number of viable fungal cells in biofilm formed on acrylic resin.

Erratum to: the acaricidal efficacy of peracetic acid and deltamethrin against the fowl tick, Argas persicus, infesting laying hens

The fowl tick, Argas persicus (Oken), is of veterinary importance as a parasite of poultry and wild birds. The antitick efficacy, in vitro and in vivo, of peracetic acid (PAA) and deltamethrin (DMT) was tested separately against A. persicus through the dipping technique. PAA (0.5%) was highly efficient against soft tick larvae (A. persicus), resulting in 100 % mortality after 2 min. The lethal concentrations LC₅₀ and LC₉₅ were 0.310 and 0.503 %, respectively. The lethal time values LT₅₀ and LT₉₅ were 5.34 and 40.00 min, respectively, after treatment with PAA (0.25%). Two minutes after exposure to DMT, LC₅₀ and LC₉₅ values were 0.0033 and 0.0052% (33.204 and 51.527 mg/L), respectively. The LT₅₀ and LT₉₅ values were 27.03 and 305.46 min, respectively, after treatment with 0.0025% DMT (25 mg/L). After dipping in PAA (0.5%), the chickens did not show respiratory signs or inflammation on the eyes and/or skin. By contrast, temporary coughing, sneezing, and ocular inflammations without dermatitis were observed in chickens dipped in DMT (0.005 % or 50 mg /L). Seven days posttreatment (PT), the reduction in the percentages of A. persicus infesting laying hens were 99.15 and 63.42% after dipping in PAA and DMT, respectively. However, complete elimination of the number of ticks occurred after 28 days PT with DMT. PAA inhibits molting effectively (28%) when compared with that of DMT (52%). Results indicated that PAA is a more potent and promising acaricide against A. persicus (in vitro and in vivo) than DMT.