Dental-Plaque Decontamination around Dental Brackets Using Antimicrobial Photodynamic Therapy: An In Vitro Study

Background: In orthodontic therapy, the enamel around brackets is very susceptible to bacterial-plaque retention, which represents a risk factor for dental tissues. The aim of this study was to evaluate the effect of methylene blue and a chlorophyllin–phycocyanin mixture, used with and without light activation, in contrast with a 2% chlorhexidine solution, on Streptococcus mutans colonies. Methods: Twenty caries-free human extracted teeth were randomized into five groups. A Streptococcus mutans suspension was inoculated on teeth in groups B, C, D, and E (A was the positive-control group). Bacterial colonies from groups C, D, and E (B was the negative-control group) were subjected to photosensitizers and 2% chlorhexidine solution. For groups C and D, a combined therapy consisting of photosensitizer and light activation was performed. The Streptococcus mutans colonies were counted, and smears were examined with an optical microscope. Two methods of statistical analysis, unidirectional analysis of variance and the Tukey–Kramer test, were used to evaluate the results. Results: A statistically significant reduction in bacterial colonies was detected after the combined therapy was applied for groups C and D, but the most marked bacterial reduction was observed for group D, where a laser-activated chlorophyll–phycocyanin mixture was used. Conclusions: Photodynamic therapy in combination with methylene blue or chlorophyllin–phycocyanin mixture sensitizers induces a statistically significant decrease in the number of bacterial colonies.

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Effect of antibacterial photodynamic therapy on Streptococcus mutans plaque biofilm in vitro

Journal of Innovative Optical Health Sciences ◽

10.1142/s1793545820500224 ◽

2020 ◽

Vol 13 (06) ◽

pp. 2050022

Author(s):

Xiaoyue Liang ◽

Zhaohui Zou ◽

Zheng Zou ◽

Changyi Li ◽

Xiaoxi Dong ◽

...

Keyword(s):

Photodynamic Therapy ◽

Lactic Acid ◽

Streptococcus Mutans ◽

Antibacterial Effect ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Saline Control ◽

Control Group ◽

Plaque Biofilm

The main objective of this study is to evaluate the antibacterial effect of antibacterial photodynamic therapy (aPDT) on Streptococcus mutans (S. mutans) biofilm model in vitro. The selection of photosensitizers is the key step for the efficacy of photodynamic therapy (PDT). However, no studies have been conducted in the oral field to compare the functional characteristics and application effects of PDT mediated by various photosensitizers. In this research, the antibacterial effect of Methylene blue (MB)/650[Formula: see text]nm laser and Hematoporphyrin monomethyl ether (HMME)/532[Formula: see text]nm laser on S. mutans biofilm was compared under different energy densities to provide experimental reference for the clinical application of the two PDT. The yield of lactic acid was analyzed by Colony forming unit (CFU) and spectrophotometry, and the complete biofilm activity was measured by Confocal Laser Scanning Microscopy (CLSM) to evaluate the bactericidal effect on each group. Based on the results of CFU, the bacterial colonies formed by 30.4[Formula: see text]J/cm2 532[Formula: see text]nm MB-aPDT group and 30.4[Formula: see text]J/cm2 532[Formula: see text]nm HMME-aPDT group were significantly less than those in other groups, and the bacterial colonies in HMME-aPDT group were less than those in HMME-aPDT group. Lactic acid production in all treatment groups except the photosensitizer group was statistically lower than that in the normal saline control group. The activity of bacterial plaque biofilm was significantly decreased in the two groups treated with 30.4[Formula: see text]J/cm2 aPDT. Therefore, aPDT suitable for energy measurement can kill S. mutans plaque biofilm, and MB-aPDT is better than HMME-aPDT.

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Antimicrobial Photodynamic Therapy in the Control of Pseudomonas syringae pv. actinidiae Transmission by Kiwifruit Pollen

Microorganisms ◽

10.3390/microorganisms8071022 ◽

2020 ◽

Vol 8 (7) ◽

pp. 1022

Author(s):

Margarida M. Lopes ◽

Maria Bartolomeu ◽

Ana T. P. C. Gomes ◽

Etelvina Figueira ◽

Ricardo Pinto ◽

...

Keyword(s):

Methylene Blue ◽

Photodynamic Therapy ◽

Pseudomonas Syringae ◽

Pollen Germination ◽

Ex Vivo ◽

Irradiation Time ◽

Antimicrobial Photodynamic Therapy ◽

Bacterial Reduction ◽

Promising Alternative

Pseudomonas syringae pv. actinidiae (Psa) is a phytopathogen responsible for bacterial canker in kiwifruit plants and can be disseminated through pollen. This study aimed to evaluate the effectiveness of antimicrobial photodynamic therapy (aPDT) in the inactivation of Psa on kiwifruit pollen using New Methylene Blue (NMB) and Methylene Blue (MB) in the presence/absence of potassium iodide (KI). Pollen germination assays were also performed to evaluate if it was affected by aPDT. Higher reduction of Psa was achieved using NMB (5.0 μM) combined with KI (100 mM) in vitro (ca. 8 log CFU mL−1 after 90 min of irradiation), while NMB alone promoted a lower reduction (3.7 log CFU mL−1). The most efficient NMB concentration with KI was used to study the photodynamic efficiency of MB (5.0 μM). MB with KI photo-inactivated Psa more efficiently than NMB, causing the same bacterial reduction (ca. 8 log CFU mL−1) in half the irradiation time (45 min). Therefore, MB was selected for the subsequent ex vivo aPDT assays in pollen. Almost all the Psa cells added artificially to the pollen (3.2 log CFU mL−1) were photo-inactivated (3.1 log CFU mL−1), whereas aPDT had a low effect on pollen natural microorganisms. When KI was added, a significant increase in aPDT effectiveness was observed (4.5 log CFU mL−1). No negative effects were observed in the pollen germination after aPDT. The results show aPDT is an effective and safe method to Psa inactivation on kiwifruit pollen, and MB use is a promising alternative in the control of Psa transmission.

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Comparative Effects of Photodynamic Therapy mediated by Curcumin on Standard and Clinical Isolate of Streptococcus mutans

The Journal of Contemporary Dental Practice ◽

10.5005/jp-journals-10024-1626 ◽

2015 ◽

Vol 16 (1) ◽

pp. 1-6 ◽

Cited By ~ 21

Author(s):

Marco Aurelio Paschoal ◽

Caroline C Tonon ◽

Marilia Correia ◽

Denise MP Spolidório ◽

Vanderlei S Bagnato ◽

...

Keyword(s):

Photodynamic Therapy ◽

Streptococcus Mutans ◽

Clinical Isolate ◽

Light Source ◽

Antimicrobial Effect ◽

Control Group ◽

Lower Sensitivity ◽

Bacterial Reduction ◽

Blue Wavelength ◽

Suspension Model

ABSTRACT Aim The aim of this study was investigate the effect of photodynamic therapy (PDT) using curcumin (C) as a photosensitizing agent irradiated with an LED (L) in the blue wavelength as a light source on a standard and clinical isolate of Streptococcus mutans (S. mutans) in a planktonic suspension model. Materials and methods Suspensions of both strains were divided into 4 groups as follows: absence of C and L (control group: C–L–), with C and without L (C group: C+L–), absence of C with L (L group: C–L+) and presence of C and L (PDT group: C+L+). Three different concentrations of curcumin (0.75 mg/ml, 1.5 mg/ml and 3 mg/ml) and three light fluences of studied light source (24, 48 and 72 J cm–2) were tested. Aliquots of each studied group was plated in BHI agar and submitted to colony forming units counting (CFU/ml) and the data transformed into logarithmical scale. Results A high photoinactivation rate of more than 70% was verified to standard S. mutans strain submitted to PDT whereas the clinical isolate showed a lower sensitivity to all the associations of curcumin and LED. A slight bacterial reduction was verified to C+L– and C–L+, demonstrating no toxic effects to the isolated application of light and photosensitizer to both S. mutans strains tested. Conclusion Photodynamic therapy using a combination of curcumin and blue LED presented a substantial antimicrobial effect on S. mutans standard strain in a planktonic suspension model with a less pronounced effect on its clinical isolate counterparts due to resistance to this alternative approach. Clinical significance Alternative antimicrobial approaches, as photodynamic therapy, should be encouraged due to optimal results against cariogenic bacteria aiming to prevent or treat dental caries. How to cite this article Tonon CC, Paschoal MA, Correia M, Spolidório DMP, Bagnato VS, Giusti JSM, Santos-Pinto L. Comparative Effects of Photodynamic Therapy mediated by Curcumin on Standard and Clinical Isolate of Streptococcus mutans. J Contemp Dent Pract 2015;16(1):1-6.

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Assessment of Photodynamic Therapy and Nanoparticles Effects on Caries Models

Open Access Macedonian Journal of Medical Sciences ◽

10.3889/oamjms.2018.241 ◽

2018 ◽

Vol 6 (7) ◽

pp. 1289-1295 ◽

Cited By ~ 11

Author(s):

Ali Saafan ◽

Mohamed H. Zaazou ◽

Marwa K. Sallam ◽

Osama Mosallam ◽

Heba A. El Danaf

Keyword(s):

Methylene Blue ◽

Photodynamic Therapy ◽

Diode Laser ◽

Streptococcus Mutans ◽

Treated Group ◽

Nano Particles ◽

Control Group ◽

P Value ◽

Ag Nps ◽

Colony Forming Units

AIM: To assess the antibacterial competence of 650 nm diode laser, Methylene Blue (MB) and Silver Nano-Particles (Ag NPs) on Streptococcus mutans in biofilm-induced caries models.MATERIAL AND METHODS: One hundred eighty specimens were prepared and equally divided into 6 groups. One group was untreated (control), and the others were subjected to either MB, laser, Ag NPs, the combination of MB and Laser or MB, laser and Ag NPs.RESULTS: Comparison of the log10 mean Colony Forming Units per millilitre (CFU/ml) values of each of the treated 5 groups and the control group was found statistically significant (P-value < 0.05).The combination of MB, laser and Ag NPs recorded the greatest reduction (95.28%). MB alone represented the least capable (74.09%). The efficiency differences among the Ag NPs treated group; the Laser treated group and the combined MB/Laser treated group were found statistically insignificant.CONCLUSION: The combination of MB, 650 nm diode laser and Ag NPs may be among the highly effective modern antimicrobial therapeutics in dentistry.

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Efficiency of Antimicrobial Photodynamic Therapy with Photodithazine® on MSSA and MRSA Strains

Antibiotics ◽

10.3390/antibiotics10070869 ◽

2021 ◽

Vol 10 (7) ◽

pp. 869

Author(s):

Beatriz Müller Nunes Souza ◽

Juliana Guerra Pinto ◽

André Henrique Correia Pereira ◽

Alejandro Guillermo Miñán ◽

Juliana Ferreira-Strixino

Keyword(s):

Staphylococcus Aureus ◽

Photodynamic Therapy ◽

Antimicrobial Photodynamic Therapy ◽

Bacterial Inactivation ◽

Bacterial Reduction ◽

Complete Inactivation ◽

Opportunistic Bacteria ◽

Significant Difference ◽

Mrsa Strains

Staphylococccus aureus is a ubiquitous and opportunistic bacteria associated with high mortality rates. Antimicrobial photodynamic therapy (aPDT) is based on the application of a light source and a photosensitizer that can interact with molecular oxygen, forming Reactive Oxygen Species (ROS) that result in bacterial inactivation. This study aimed to analyze, in vitro, the action of aPDT with Photodithazine® (PDZ) in methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) strains. The strains were incubated with PDZ at 25, 50, 75, and 100 mg/L for 15 min and irradiated with fluences of 25, 50, and 100 J/cm2. The internalization of PDZ was evaluated by confocal microscopy, the bacterial growth by counting the number of colony-forming units, as well as the bacterial metabolic activity post-aPDT and the production of ROS. In both strains, the photosensitizer was internalized; the production of ROS increased when the aPDT was applied; there was a bacterial reduction compared to the control at all the evaluated fluences and concentrations; and, in most parameters, it was obtained complete inactivation with significant difference (p < 0.05). The implementation of aPDT with PDZ in clinical strains of S. aureus has resulted in its complete inactivation, including the MRSA strains.

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Antimicrobial effect of methylene blue formulations with oxygen carrier at different pHs: preliminary study

Brazilian Dental Science ◽

10.14295/bds.2019.v22i1.1635 ◽

2019 ◽

Vol 22 (1) ◽

pp. Process

Author(s):

Jessica Klöckner Knorst ◽

Gabriela Scarton Barriquello ◽

Marcos Antônio Villetti ◽

Roberto Christ Vianna Santos ◽

Karla Zanini Kantorski

Keyword(s):

Methylene Blue ◽

Pseudomonas Aeruginosa ◽

Photodynamic Therapy ◽

Oxygen Carrier ◽

Statistical Significance ◽

Antimicrobial Effect ◽

Control Group ◽

Preliminary Study ◽

Post Hoc ◽

Multispecies Biofilms

Objective: Evaluate methylene blue (MB) formulations containing oxygen carrier at different pHs in antimicrobial photodynamic therapy (aPDT). Material and Methods: Biofilms of Pseudomonas aeruginosa PA01 formed over acrylics specimens during five days were treated with aPDT using different formulations: MB/pH 7.4; MB/pH 5.6; MB/carrier pH 7.4; MB/carrier pH 5.6. Biofilms not exposed to treatment were used as a control. Blind examiner for the experimental groups performed the counting of colonies per ml suspension (CFU/ml). Two-way ANOVA was used to determine the effect of factors solvent (carrier vs water) and pH (7.4 vs 5.6). One-way ANOVA and post-hoc Tukey’s test was used to evaluate differences among the five groups (control; MB/carrier pH 7.4; MB pH 7.4; MB/carrier pH 5.6; MB pH 5.6). The Statistics 8.0 software was used (P<0.05). Results: All of photodynamic therapy groups showed significant reduction in P. aeruginosa compared to the control group. The solvent factor was not significant (P=0.18), while the pH factor presented statistical significance (P=0.01). When the carrier was used, MB formulation at pH 7.4 presented a statistically greater reduction of P. aeruginosa than the formulation with pH 5.6. Conclusion: The PDT using methylene blue formulations with oxygen carrier demonstrated potential for the treatment of localized infections by P. aeruginosa. MB formulations with oxygen carrier and pH 7.4 resulted in higher antimicrobial effect and should be considered for future studies with multispecies biofilms. KeywordsAntimicrobial photodynamic therapy; biofilm; laser; Pseudomonas aeruginosa.

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