Bactericidal Effect of 2780 nm Er,Cr:YSGG Laser Combined with 940 nm Diode Laser in Enterococcus faecalis Elimination: A Comparative Study

Abstract Background/Aims Today, the using of diode lasers in dentistry has made a significant progress; it increased the speed of treatment, decreased the time of healing, and showed a bactericidal effect. The thermal effects should be considered in root canal treatment by laser, as the temperature rises to critical levels, causing tissues damage and any thermal change occurs after laser irradiation. The temperature can rise up to 10 °C above the body temperature for less than 2–3 min without damaging the periodontal tissue or burring the tooth structure by using cooling. Antibacterial properties of silver nanoparticles (Ag-NPs) were reducing Gram-positive and Gram-negative bacterial growth, due to a larger surface to volume ratio of nanoparticles. The goal of this study is to evaluate the bactericidal effect of diode laser irradiation (970 nm), the silver nanoparticles in root canals infected by Enterococcus faecalis bacteria, and the thermal change that occurs after laser application. Materials and methods Forty-five extracted single-rooted human maxillary anterior teeth were collected and used as a container for the test. The samples are inoculated by Enterococcus faecalis bacterial strain and randomly divided into three groups: group I (control) (n = 15), group II (Enterococcus faecalis bacteria and silver nanoparticles) (n = 15), and group III (Enterococcus faecalis bacteria and diode laser) (n = 15). The laser group was divided into subgroups according to the time of laser irradiation (20 s, 30 s, and 40 s). Results There was a significant difference between the treated groups, in which the laser group showed a high bactericidal effect than the other groups at the time of radiation 40 s, without damaging the tooth structure or periodontal ligament. Conclusion Diode laser with proper parameters is used as an adjunctive endodontic disinfection modality due to its antibacterial effect with a temperature tolerated by periodontal tissues with safety limit.

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Effectiveness of Diode Laser versus Intense Pulsed Light in Hirsutism: A Prospective and Comparative Study in Samawa City

International Journal of Psychosocial Rehabilitation ◽

10.37200/ijpr/v24i2/pr200511 ◽

2020 ◽

Vol 24 (02) ◽

pp. 2111-2117

Author(s):

Arwaa A. Abdul-hussein ◽

Safa Azhar Razzaq ◽

Haidar Hamid Shak

Keyword(s):

Comparative Study ◽

Diode Laser ◽

Intense Pulsed Light ◽

Pulsed Light

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PSIX-18 Laurate and its glycerol monoester, monolaurin, as potential additives to control Listeria monocytogenes and tetracycline resistant Enterococcus faecalis in air-exposed silage

Journal of Animal Science ◽

10.1093/jas/skaa278.724 ◽

2020 ◽

Vol 98 (Supplement_4) ◽

pp. 414-415

Author(s):

Yamicela Castillo-Castillo ◽

Marina Ontiveros ◽

Eric J Scholljegerdes ◽

Robin Anderson ◽

Claudio Arzola-Alvarez ◽

...

Keyword(s):

Listeria Monocytogenes ◽

Enterococcus Faecalis ◽

Brain Heart Infusion ◽

Bactericidal Effect ◽

Complete Elimination ◽

Gram Positive Bacteria ◽

Viable Cells ◽

Colony Forming Units ◽

Feed Value ◽

Risk Infection

Abstract Silages can harbor pathogenic and antimicrobial resistant microbes which risk infection of food-producing animals. Livestock producers need effective yet environmentally friendly interventions to preserve the feed value of these fermented materials. Medium chain fatty acids such as laurate and its glycerol monoester, monolaurin, are potent inhibitors of many Gram-positive bacteria and when tested at 5 mg/mL in anaerobic cultures (n = 3/treatment) inoculated with 105 colony forming units (CFU) of Listeria monocytogenes and grown at 37oC in ½ strength Brain Heart infusion broth achieved near complete elimination of viable cells after 6 h compared to a 2.2 ± 0.1 log10 CFU/mL increase observed in controls. Culture of a tetracycline-resistant Enterococcus faecalis with 5 mg laurate/mL likewise achieved near complete elimination of viable cells (5 log10 CFU/mL) by 6 h incubation. The bactericidal effect of 5 mg monolaurin was less against E. faecalis, achieving a decrease of 1.8 ± 0.2 log10 CFU/mL and not decreased further after 24 h. When tested against air-exposed silage, pH 7.53 (4 g), mixed with 4 mL water, 5 mg laurate or monolaurin decreased viability of experimentally-inoculated L. monocytogenes (105 CFU/g silage) more (P < 0.05) than untreated controls after 24 h aerobic incubation (22oC), with viable counts being decreased 6.3 ± 0.1, 5.9 ± 0.8 and 4.5 ± 0.1 log10 CFU/g, respectively. In contrast, viable recovery of the experimentally-inoculated (105 CFU/g) tetracycline-resistant E. faecalis was reduced more (P < 0.05) than controls (decreased 0.7 ± 0.1 log10 CFU/g) after 6 h incubation when similarly tested with laurate and monolaurin (1.7 ± 0.5 and 3.0 ± 0.9 log10 CFU/g, respectively) but counts after 24 h were similar, decreasing on average 2.0 ± 0.5 log10 CFU/g). Results indicate laurate and monolaurin may be useful in killing L. monocytogenes and tetracycline-resistant E. faecalis during silage feed-out.

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The Effect of Antimicrobial Photodynamic Therapy Using Chlorophyllin–Phycocyanin Mixture on Enterococcus faecalis: The Influence of Different Light Sources

Applied Sciences ◽

10.3390/app10124290 ◽

2020 ◽

Vol 10 (12) ◽

pp. 4290 ◽

Cited By ~ 4

Author(s):

Nasim Chiniforush ◽

Maryam Pourhajibagher ◽

Steven Parker ◽

Stefano Benedicenti ◽

Abbas Bahador ◽

...

Keyword(s):

Photodynamic Therapy ◽

Diode Laser ◽

Enterococcus Faecalis ◽

Control Group ◽

Human Gingival Fibroblast ◽

Light Sources ◽

Gingival Fibroblast ◽

Antimicrobial Photodynamic Therapy ◽

Cell Viability Assay ◽

Vitro Effect

The purpose of this study was to evaluate the in vitro effect of the chlorophyllin–phycocyanin mixture (Photoactive+) as a photosensitizer (PS) during antimicrobial photodynamic therapy (aPDT) on the count of Enterococcus faecalis (E. faecalis) using different light sources. The antimicrobial effect of aPDT with chlorophyllin–phycocyanin mixture using different light sources including diode laser (λ = 660 nm), diode laser (λ = 635 nm), LED (λ = 450 ± 30 nm) alone or in combination was assessed using microbial cell viability assay against E. faecalis. In addition, the cell cytotoxicity of Photoactive+ was assessed on human gingival fibroblast (HuGu) cells by MTT assay; E. faecalis growth when treated by both red wavelengths (635 nm, 660 nm) and combination of LED (420–480 nm) and red wavelengths (635 nm, 660 nm), significantly reduced compared to the control group (p < 0.05). There was no significant reduction in the number of viable cells exposed to Photoactive+ compared to the control group (p < 0.05). This study shows that the application of chlorophyllin–phycocyanin mixture and irradiation with emission of red light achieved a better result for bacterial count reduction, compared to a control. This component can be applied safely due to very negligible cytotoxicity.

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Bactericidal Effects of Diode Laser Irradiation on Enterococcus faecalis Using Periapical Lesion Defect Model

ISRN Dentistry ◽

10.5402/2011/870364 ◽

2011 ◽

Vol 2011 ◽

pp. 1-6 ◽

Cited By ~ 11

Author(s):

Masato Nagayoshi ◽

Tatsuji Nishihara ◽

Keisuke Nakashima ◽

Shigetsugu Iwaki ◽

Ker-Kong Chen ◽

...

Keyword(s):

Laser Irradiation ◽

Diode Laser ◽

Enterococcus Faecalis ◽

Periapical Lesion ◽

Lesion Area ◽

Defect Model ◽

Cytotoxic Effects ◽

Periapical Lesions ◽

Bactericidal Effects

Objective. Photodynamic therapy has been expanded for use in endodontic treatment. The aim of this study was to investigate the antimicrobial effects of diode laser irradiation on endodontic pathogens in periapical lesions using an in vitro apical lesion model. Study Design. Enterococcus faecalis in 0.5% semisolid agar with a photosensitizer was injected into apical lesion area of in vitro apical lesion model. The direct effects of irradiation with a diode laser as well as heat produced by irradiation on the viability of microorganisms in the lesions were analyzed. Results. The viability of E. faecalis was significantly reduced by the combination of a photosensitizer and laser irradiation. The temperature caused by irradiation rose, however, there were no cytotoxic effects of heat on the viability of E. faecalis. Conclusion. Our results suggest that utilization of a diode laser in combination with a photosensitizer may be useful for clinical treatment of periapical lesions.

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