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Julio Almeida Silva - One of the best experts on this subject based on the ideXlab platform.
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Antimicrobial Efficacy of ozonated water gaseous ozone sodium hypochlorite and chlorhexidine in infected human root canals
International Endodontic Journal, 2007Co-Authors: C Estrela, Cyntia Rodrigues De Araujo Estrela, Daniel De Almeida Decurcio, Augusto Cesar Braz Hollanda, Julio Almeida SilvaAbstract:AIM: To determine the Antimicrobial Efficacy of ozonated water, gaseous ozone, sodium hypochlorite and chlorhexidine in human root canals infected by Enterococcus faecalis. METHODOLOGY: Thirty human maxillary anterior teeth were prepared and inoculated with E. faecalis for 60 days. Eppendorf tubes were connected to the coronal portion of the teeth. Urethane hoses were attached to the tubes and to the entrance of a peristaltic pump. The exit of the apparatus corresponded to the apical portion of the root canals. The test irrigating solutions were ozonated water, gaseous ozone, 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine that circulated at a constant flow of 50 mL min(-1) for 20 min. Samples from the root canals were collected and immersed in 7 mL Letheen Broth (LB), followed by incubation at 37 degrees C for 48 h. Bacterial growth was analysed by turbidity of the culture medium and subculture on a specific nutrient broth. A 0.1 mL inoculum obtained from LB was transferred to 7 mL of brain heart infusion and incubated at 37 degrees C for 48 h. Bacterial growth was checked by turbidity of the culture medium carried out in triplicate. RESULTS: No solution used as an irrigant over a 20-min contact time demonstrated an Antimicrobial effect against E. faecalis. CONCLUSION: The irrigation of infected human root canals with ozonated water, 2.5% NaOCl, 2% chlorhexidine and the application of gaseous ozone for 20 min was not sufficient to inactivate E. faecalis.
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Antimicrobial Efficacy of ozonated water gaseous ozone sodium hypochlorite and chlorhexidine in infected human root canals
International Endodontic Journal, 2007Co-Authors: C Estrela, Cyntia Rodrigues De Araujo Estrela, Daniel De Almeida Decurcio, Augusto Cesar Braz Hollanda, Julio Almeida SilvaAbstract:Aim To determine the Antimicrobial Efficacy of ozonated water, gaseous ozone, sodium hypochlorite and chlorhexidine in human root canals infected by Enterococcus faecalis. Methodology Thirty human maxillary anterior teeth were prepared and inoculated with E. faecalis for 60 days. Eppendorf tubes were connected to the coronal portion of the teeth. Urethane hoses were attached to the tubes and to the entrance of a peristaltic pump. The exit of the apparatus corresponded to the apical portion of the root canals. The test irrigating solutions were ozonated water, gaseous ozone, 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine that circulated at a constant flow of 50 mL min−1 for 20 min. Samples from the root canals were collected and immersed in 7 mL Letheen Broth (LB), followed by incubation at 37 °C for 48 h. Bacterial growth was analysed by turbidity of the culture medium and subculture on a specific nutrient broth. A 0.1 mL inoculum obtained from LB was transferred to 7 mL of brain heart infusion and incubated at 37 °C for 48 h. Bacterial growth was checked by turbidity of the culture medium carried out in triplicate. Results No solution used as an irrigant over a 20-min contact time demonstrated an Antimicrobial effect against E. faecalis. Conclusion The irrigation of infected human root canals with ozonated water, 2.5% NaOCl, 2% chlorhexidine and the application of gaseous ozone for 20 min was not sufficient to inactivate E. faecalis.
David Julian Mcclements - One of the best experts on this subject based on the ideXlab platform.
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fabrication stability and Efficacy of dual component Antimicrobial nanoemulsions essential oil thyme oil and cationic surfactant lauric arginate
Food Chemistry, 2015Co-Authors: Yuhua Chang, David Julian Mcclements, Lynne MclandsboroughAbstract:The influence of a cationic surfactant (lauric arginate, LAE) on the physical properties and Antimicrobial Efficacy of thyme oil nanoemulsions was investigated. Nanoemulsions prepared from pure thyme oil were highly unstable due to Ostwald ripening, but they could be stabilized by adding a ripening inhibitor (corn oil) to the oil phase prior to homogenisation. The loading capacity and Antimicrobial Efficacy of thyme oil nanoemulsions were significantly increased by adding LAE. In the absence of LAE, at least 60 wt% corn oil had to be added to the lipid phase to inhibit Ostwald ripening; but in the presence of 0.1 wt% LAE, only 30 wt% corn oil was needed. LAE addition substantially increased the Antimicrobial Efficacy of the thyme oil nanoemulsions: 200 μg/ml thyme oil was needed to inhibit growth of a spoilage yeast (Zygosaccharomyces bailii) if LAE was added, whereas ⩾ 400 μg/ml was needed in the absence of LAE.
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physicochemical properties and Antimicrobial Efficacy of carvacrol nanoemulsions formed by spontaneous emulsification
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Yuhua Chang, Lynne Mclandsborough, David Julian McclementsAbstract:A simple cost-effective method (spontaneous emulsification) for fabricating physically stable Antimicrobial nanoemulsions from essential oils is described. These nanoemulsions (10 wt % total oil phase) were formed by titration of a mixture of essential oil (carvacrol), carrier oil (medium chain triglyceride, MCT), and nonionic surfactant (Tween) into an aqueous solution with continuous stirring. Oil phase composition (carvacrol-to-MCT mass ratio) had a major impact on initial droplet diameter, with the smallest droplets (d ≈ 55 nm) being formed at 2.5 wt % carvacrol and 7.5 wt % MCT. Surfactant type also had an appreciable impact on mean droplet diameter, with Tween 80 giving the smallest droplets (d ≈ 55 nm) from a group of food-grade nonionic surfactants (Tween 20, 40, 60, 80, and 85). The droplet size also decreased (from >5000 to <25 nm) as the total surfactant concentration was increased (from 5 to 20 wt %). The long-term stability and Antimicrobial Efficacy of selected nanoemulsions was examined at ...
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physical properties and Antimicrobial Efficacy of thyme oil nanoemulsions influence of ripening inhibitors
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Yuhua Chang, Lynne Mclandsborough, David Julian McclementsAbstract:Thyme oil-in-water nanoemulsions (pH 3.5) were prepared as potential Antimicrobial delivery systems. The nanoemulsions were highly unstable to droplet growth and phase separation, which was attributed to Ostwald ripening due to the relatively high water solubility of thyme oil. Ostwald ripening could be inhibited by mixing thyme oil with a water-insoluble ripening inhibitor (≥60 wt % corn oil or ≥50 wt % MCT in the lipid phase) before homogenization, yielding nanoemulsions with good physical stability. Physically stable thyme oil nanoemulsions were examined for their Antimicrobial activities against an acid-resistant spoilage yeast, Zygosaccharomyces bailii (ZB). Oil phase composition (ripening inhibitor type and concentration) had an appreciable influence on the Antimicrobial activity of the thyme oil nanoemulsions. In general, increasing the ripening inhibitor levels in the lipid phase reduced the Antimicrobial Efficacy of nanoemulsions. For example, for nanoemulsions containing 60 wt % corn oil in the ...
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physical properties and Antimicrobial Efficacy of thyme oil nanoemulsions influence of ripening inhibitors
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Yuhua Chang, Lynne Mclandsborough, David Julian McclementsAbstract:Thyme oil-in-water nanoemulsions (pH 3.5) were prepared as potential Antimicrobial delivery systems. The nanoemulsions were highly unstable to droplet growth and phase separation, which was attributed to Ostwald ripening due to the relatively high water solubility of thyme oil. Ostwald ripening could be inhibited by mixing thyme oil with a water-insoluble ripening inhibitor (≥60 wt % corn oil or ≥50 wt % MCT in the lipid phase) before homogenization, yielding nanoemulsions with good physical stability. Physically stable thyme oil nanoemulsions were examined for their Antimicrobial activities against an acid-resistant spoilage yeast, Zygosaccharomyces bailii (ZB). Oil phase composition (ripening inhibitor type and concentration) had an appreciable influence on the Antimicrobial activity of the thyme oil nanoemulsions. In general, increasing the ripening inhibitor levels in the lipid phase reduced the Antimicrobial Efficacy of nanoemulsions. For example, for nanoemulsions containing 60 wt % corn oil in the lipid phase, the minimum inhibitory concentration (MIC) of thyme oil to inhibit ZB growth was 375 μg/mL, while for nanoemulsions containing 90 wt % corn oil in the lipid phase, even 6000 μg/mL thyme oil could not inhibit ZB growth. This effect is also dependent on ripening inhibitor types: at the same concentration in the lipid phase, MCT decreased the Antimicrobial Efficacy of thyme oil more than corn oil. For instance, when the level of ripening inhibitor in the lipid phase was 70 wt %, the MICs of thyme oil for nanoemulsions containing corn oil and MCT were 750 and 3000 μg/mL, respectively. The results of this study have important implications for the design and utilization of nanoemulsions as Antimicrobial delivery systems in the food and other industries.
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cationic Antimicrobial e polylysine anionic polysaccharide pectin interactions influence of polymer charge on physical stability and Antimicrobial Efficacy
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Yuhua Chang, Lynne Mclandsborough, David Julian McclementsAbstract:The cationic biopolymer e-polylysine (e-PL) is a potent food-grade Antimicrobial that is highly effective against a range of food pathogens and spoilage organisms. In compositionally complex systems such as foods and beverages, cationic e-PL molecules may associate with anionic substances, leading to increased turbidity, sediment formation, and reduced Antimicrobial activity. This study therefore characterized the interactions between cationic e-PL and anionic pectins with different degrees of esterification (DE) and then investigated the influence of these interactions on the Antimicrobial Efficacy of e-PL. The nature of the interactions was characterized using isothermal titration calorimetry (ITC), microelectrophoresis (ME), and turbidity measurements. High (DE 61%), medium (DE 51%), and low (DE 42%) methoxyl pectins interacted with e-PL molecules through electrostatic forces, forming either soluble or insoluble complexes with various electrical charges, depending on the relative mass ratio of pectin and e-PL. The interaction of pectin with e-PL increased as the negative charge density on the pectin molecules increased, that is, with decreasing DE. The Antimicrobial Efficacy of e-PL against two acid-resistant spoilage yeasts (Zygosaccharomyces bailii and Saccharomyces cerevisiae) decreased progressively in the presence of increasing levels of all three pectins. Nevertheless, the low DE pectin decreased the Antimicrobial Efficacy of e-PL much more dramatically, likely due to strong electrostatic binding of e-PL onto low DE pectin molecules reducing its interaction with anionic microbe surfaces. This study provides knowledge that will facilitate the rational application of e-PL as an Antimicrobial in complex food systems.
C Estrela - One of the best experts on this subject based on the ideXlab platform.
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Antimicrobial Efficacy of ozonated water gaseous ozone sodium hypochlorite and chlorhexidine in infected human root canals
International Endodontic Journal, 2007Co-Authors: C Estrela, Cyntia Rodrigues De Araujo Estrela, Daniel De Almeida Decurcio, Augusto Cesar Braz Hollanda, Julio Almeida SilvaAbstract:AIM: To determine the Antimicrobial Efficacy of ozonated water, gaseous ozone, sodium hypochlorite and chlorhexidine in human root canals infected by Enterococcus faecalis. METHODOLOGY: Thirty human maxillary anterior teeth were prepared and inoculated with E. faecalis for 60 days. Eppendorf tubes were connected to the coronal portion of the teeth. Urethane hoses were attached to the tubes and to the entrance of a peristaltic pump. The exit of the apparatus corresponded to the apical portion of the root canals. The test irrigating solutions were ozonated water, gaseous ozone, 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine that circulated at a constant flow of 50 mL min(-1) for 20 min. Samples from the root canals were collected and immersed in 7 mL Letheen Broth (LB), followed by incubation at 37 degrees C for 48 h. Bacterial growth was analysed by turbidity of the culture medium and subculture on a specific nutrient broth. A 0.1 mL inoculum obtained from LB was transferred to 7 mL of brain heart infusion and incubated at 37 degrees C for 48 h. Bacterial growth was checked by turbidity of the culture medium carried out in triplicate. RESULTS: No solution used as an irrigant over a 20-min contact time demonstrated an Antimicrobial effect against E. faecalis. CONCLUSION: The irrigation of infected human root canals with ozonated water, 2.5% NaOCl, 2% chlorhexidine and the application of gaseous ozone for 20 min was not sufficient to inactivate E. faecalis.
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Antimicrobial Efficacy of ozonated water gaseous ozone sodium hypochlorite and chlorhexidine in infected human root canals
International Endodontic Journal, 2007Co-Authors: C Estrela, Cyntia Rodrigues De Araujo Estrela, Daniel De Almeida Decurcio, Augusto Cesar Braz Hollanda, Julio Almeida SilvaAbstract:Aim To determine the Antimicrobial Efficacy of ozonated water, gaseous ozone, sodium hypochlorite and chlorhexidine in human root canals infected by Enterococcus faecalis. Methodology Thirty human maxillary anterior teeth were prepared and inoculated with E. faecalis for 60 days. Eppendorf tubes were connected to the coronal portion of the teeth. Urethane hoses were attached to the tubes and to the entrance of a peristaltic pump. The exit of the apparatus corresponded to the apical portion of the root canals. The test irrigating solutions were ozonated water, gaseous ozone, 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine that circulated at a constant flow of 50 mL min−1 for 20 min. Samples from the root canals were collected and immersed in 7 mL Letheen Broth (LB), followed by incubation at 37 °C for 48 h. Bacterial growth was analysed by turbidity of the culture medium and subculture on a specific nutrient broth. A 0.1 mL inoculum obtained from LB was transferred to 7 mL of brain heart infusion and incubated at 37 °C for 48 h. Bacterial growth was checked by turbidity of the culture medium carried out in triplicate. Results No solution used as an irrigant over a 20-min contact time demonstrated an Antimicrobial effect against E. faecalis. Conclusion The irrigation of infected human root canals with ozonated water, 2.5% NaOCl, 2% chlorhexidine and the application of gaseous ozone for 20 min was not sufficient to inactivate E. faecalis.
Hemanshi Kumar - One of the best experts on this subject based on the ideXlab platform.
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an in vitro evaluation of the Antimicrobial Efficacy of curcuma longa tachyspermum ammi chlorhexidine gluconate and calcium hydroxide on enterococcus faecalis
Journal of Conservative Dentistry, 2013Co-Authors: Hemanshi KumarAbstract:Aim and Objectives: This in vitro study was designed to comparatively evaluate the Antimicrobial Efficacy of Curcuma longa (turmeric - T 1 -10%, T 2 -20%); Tachyspermum ammi (ajwain - A 1 -10%, A 2 -20%); chlorhexidine (CHX) gluconate gel (hexigel - 1%); and calcium hydroxide (10%) as intracanal medicaments against Enterococcus faecalis . Materials and Methods: Agar plates were prepared using brain-heart infusion (BHI) agar. Cultures of E. faecalis were grown in BHI broth at 37°C. Well diffusion method was used to derive results. Plates were inoculated for 72 h at 37°C and microbial zones of inhibition were recorded. Statistical analysis was performed with repeated measures analysis of variance. Results: C. longa (T 2 -20%) and CHX gluconate gel (hexigel - CHX-1%) showed larger zones of microbial inhibition than C. longa (T 1 -10%) that were statistically significant ( P (ajwain - A 1 and A 2 ) and calcium hydroxide. Conclusion: C. longa can be used as intracanal medicament in endodontic failure cases.
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an in vitro evaluation of the Antimicrobial Efficacy of curcuma longa tachyspermum ammi chlorhexidine gluconate and calcium hydroxide on enterococcus faecalis
Journal of Conservative Dentistry, 2013Co-Authors: Hemanshi KumarAbstract:Aim and Objectives: This in vitro study was designed to comparatively evaluate the Antimicrobial Efficacy of Curcuma longa (turmeric - T 1 -10%, T 2 -20%); Tachyspermum ammi (ajwain - A 1 -10%, A 2 -20%); chlorhexidine (CHX) gluconate gel (hexigel - 1%); and calcium hydroxide (10%) as intracanal medicaments against Enterococcus faecalis. Materials and Methods: Agar plates were prepared using brain-heart infusion (BHI) agar. Cultures of E. faecalis were grown in BHI broth at 37°C. Well diffusion method was used to derive results. Plates were inoculated for 72 h at 37°C and microbial zones of inhibition were recorded. Statistical analysis was performed with repeated measures analysis of variance. Results: C. longa (T 2 -20%) and CHX gluconate gel (hexigel - CHX-1%) showed larger zones of microbial inhibition than C. longa (T 1 -10%) that were statistically significant (P Conclusion: C. longa can be used as intracanal medicament in endodontic failure cases.
Yuhua Chang - One of the best experts on this subject based on the ideXlab platform.
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fabrication stability and Efficacy of dual component Antimicrobial nanoemulsions essential oil thyme oil and cationic surfactant lauric arginate
Food Chemistry, 2015Co-Authors: Yuhua Chang, David Julian Mcclements, Lynne MclandsboroughAbstract:The influence of a cationic surfactant (lauric arginate, LAE) on the physical properties and Antimicrobial Efficacy of thyme oil nanoemulsions was investigated. Nanoemulsions prepared from pure thyme oil were highly unstable due to Ostwald ripening, but they could be stabilized by adding a ripening inhibitor (corn oil) to the oil phase prior to homogenisation. The loading capacity and Antimicrobial Efficacy of thyme oil nanoemulsions were significantly increased by adding LAE. In the absence of LAE, at least 60 wt% corn oil had to be added to the lipid phase to inhibit Ostwald ripening; but in the presence of 0.1 wt% LAE, only 30 wt% corn oil was needed. LAE addition substantially increased the Antimicrobial Efficacy of the thyme oil nanoemulsions: 200 μg/ml thyme oil was needed to inhibit growth of a spoilage yeast (Zygosaccharomyces bailii) if LAE was added, whereas ⩾ 400 μg/ml was needed in the absence of LAE.
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physicochemical properties and Antimicrobial Efficacy of carvacrol nanoemulsions formed by spontaneous emulsification
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Yuhua Chang, Lynne Mclandsborough, David Julian McclementsAbstract:A simple cost-effective method (spontaneous emulsification) for fabricating physically stable Antimicrobial nanoemulsions from essential oils is described. These nanoemulsions (10 wt % total oil phase) were formed by titration of a mixture of essential oil (carvacrol), carrier oil (medium chain triglyceride, MCT), and nonionic surfactant (Tween) into an aqueous solution with continuous stirring. Oil phase composition (carvacrol-to-MCT mass ratio) had a major impact on initial droplet diameter, with the smallest droplets (d ≈ 55 nm) being formed at 2.5 wt % carvacrol and 7.5 wt % MCT. Surfactant type also had an appreciable impact on mean droplet diameter, with Tween 80 giving the smallest droplets (d ≈ 55 nm) from a group of food-grade nonionic surfactants (Tween 20, 40, 60, 80, and 85). The droplet size also decreased (from >5000 to <25 nm) as the total surfactant concentration was increased (from 5 to 20 wt %). The long-term stability and Antimicrobial Efficacy of selected nanoemulsions was examined at ...
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physical properties and Antimicrobial Efficacy of thyme oil nanoemulsions influence of ripening inhibitors
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Yuhua Chang, Lynne Mclandsborough, David Julian McclementsAbstract:Thyme oil-in-water nanoemulsions (pH 3.5) were prepared as potential Antimicrobial delivery systems. The nanoemulsions were highly unstable to droplet growth and phase separation, which was attributed to Ostwald ripening due to the relatively high water solubility of thyme oil. Ostwald ripening could be inhibited by mixing thyme oil with a water-insoluble ripening inhibitor (≥60 wt % corn oil or ≥50 wt % MCT in the lipid phase) before homogenization, yielding nanoemulsions with good physical stability. Physically stable thyme oil nanoemulsions were examined for their Antimicrobial activities against an acid-resistant spoilage yeast, Zygosaccharomyces bailii (ZB). Oil phase composition (ripening inhibitor type and concentration) had an appreciable influence on the Antimicrobial activity of the thyme oil nanoemulsions. In general, increasing the ripening inhibitor levels in the lipid phase reduced the Antimicrobial Efficacy of nanoemulsions. For example, for nanoemulsions containing 60 wt % corn oil in the ...
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physical properties and Antimicrobial Efficacy of thyme oil nanoemulsions influence of ripening inhibitors
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Yuhua Chang, Lynne Mclandsborough, David Julian McclementsAbstract:Thyme oil-in-water nanoemulsions (pH 3.5) were prepared as potential Antimicrobial delivery systems. The nanoemulsions were highly unstable to droplet growth and phase separation, which was attributed to Ostwald ripening due to the relatively high water solubility of thyme oil. Ostwald ripening could be inhibited by mixing thyme oil with a water-insoluble ripening inhibitor (≥60 wt % corn oil or ≥50 wt % MCT in the lipid phase) before homogenization, yielding nanoemulsions with good physical stability. Physically stable thyme oil nanoemulsions were examined for their Antimicrobial activities against an acid-resistant spoilage yeast, Zygosaccharomyces bailii (ZB). Oil phase composition (ripening inhibitor type and concentration) had an appreciable influence on the Antimicrobial activity of the thyme oil nanoemulsions. In general, increasing the ripening inhibitor levels in the lipid phase reduced the Antimicrobial Efficacy of nanoemulsions. For example, for nanoemulsions containing 60 wt % corn oil in the lipid phase, the minimum inhibitory concentration (MIC) of thyme oil to inhibit ZB growth was 375 μg/mL, while for nanoemulsions containing 90 wt % corn oil in the lipid phase, even 6000 μg/mL thyme oil could not inhibit ZB growth. This effect is also dependent on ripening inhibitor types: at the same concentration in the lipid phase, MCT decreased the Antimicrobial Efficacy of thyme oil more than corn oil. For instance, when the level of ripening inhibitor in the lipid phase was 70 wt %, the MICs of thyme oil for nanoemulsions containing corn oil and MCT were 750 and 3000 μg/mL, respectively. The results of this study have important implications for the design and utilization of nanoemulsions as Antimicrobial delivery systems in the food and other industries.
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cationic Antimicrobial e polylysine anionic polysaccharide pectin interactions influence of polymer charge on physical stability and Antimicrobial Efficacy
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Yuhua Chang, Lynne Mclandsborough, David Julian McclementsAbstract:The cationic biopolymer e-polylysine (e-PL) is a potent food-grade Antimicrobial that is highly effective against a range of food pathogens and spoilage organisms. In compositionally complex systems such as foods and beverages, cationic e-PL molecules may associate with anionic substances, leading to increased turbidity, sediment formation, and reduced Antimicrobial activity. This study therefore characterized the interactions between cationic e-PL and anionic pectins with different degrees of esterification (DE) and then investigated the influence of these interactions on the Antimicrobial Efficacy of e-PL. The nature of the interactions was characterized using isothermal titration calorimetry (ITC), microelectrophoresis (ME), and turbidity measurements. High (DE 61%), medium (DE 51%), and low (DE 42%) methoxyl pectins interacted with e-PL molecules through electrostatic forces, forming either soluble or insoluble complexes with various electrical charges, depending on the relative mass ratio of pectin and e-PL. The interaction of pectin with e-PL increased as the negative charge density on the pectin molecules increased, that is, with decreasing DE. The Antimicrobial Efficacy of e-PL against two acid-resistant spoilage yeasts (Zygosaccharomyces bailii and Saccharomyces cerevisiae) decreased progressively in the presence of increasing levels of all three pectins. Nevertheless, the low DE pectin decreased the Antimicrobial Efficacy of e-PL much more dramatically, likely due to strong electrostatic binding of e-PL onto low DE pectin molecules reducing its interaction with anionic microbe surfaces. This study provides knowledge that will facilitate the rational application of e-PL as an Antimicrobial in complex food systems.