Photodynamic inactivation of planktonic cultures of Streptococcus mutans using erythrosine irradiated by LED / Inativação fotodinâmica de culturas planctônicas de Streptococcus mutans usando eritrosina irradiada por LED

Objective: The aim of this in vitro study was to evaluate the efficacy of photodynamic inactivation (PDI) with erythrosine (E), using a light-emitting diode (LED) on planktonic cultures of Streptococcus mutans. Material and Methods: A Streptococcus mutans strain (UA 159) was used to prepare the suspensions containing 107 cells/mL, which was tested under different experimental conditions: a) LED irradiation in the presence of erythrosine as a photosensitizer (E+L+); b) LED irradiation only (P-L+); c) treatment with erythrosine only (E+L-); and d) no LED irradiation or photosensitizer (P) treatment, which served as a control group (P-L-). After treatment, strains were seeded onto MSBS agar for determination of the number of colony-forming units (CFU/mL). Results: The results were submitted to analysis of variance and the Tukey test (p < 0.05). No reduction in the number of CFU/mL was observed in the treatment group with erythrosine (E+L+) when compared to the control (P-L-). Conclusion: PDI using erythrosine did not reduce the number of CFUs per millimeter within the parameters in this study. (AU)

Objetivo: o objetivo deste estudo in vitro foi avaliar a eficácia da inativação fotodinâmica (PDI) com a eritrosina (E), usando diodo de emissão de luz azul (LED) em culturas planctônicas de Streptococcus mutans. Material e métodos: a cepa de Streptococcus mutans (UA 159) foi usada para o preparo das suspensões padrões contendo 107 células/mL, as quais foram testadas em diferentes condições experimentais a) irradiação com LED em presença da eritrosina como fotossensibilizador (E+L+); b) irradiação com LED apenas (F-L+); c) tratamento com eritrosina apenas (E+L-); e d) tratamento sem irradiação com LED ou fotossensibilizador (F), que serviu como grupo controle (F-L-). Após o tratamento, as cepas foram semeadas em ágar MSBS para determinação do número de unidades formadoras de colônias (UFC/mL). Resultados: os resultados foram submetidos à análise de variância e teste de Tukey (p < 0.05). Não foi observada redução no número de UFC/mL no grupo de tratamento com eritrosina (E+L+) quando comparado ao grupo controle (F-L-). Conclusão: a PDI usando etritrosina e LED não reduziu o número de UFCs por milímetro com os parâmetros utilizados neste estudo.(AU)

Color stability of three dimensional-printed denture teeth exposed to various colorants / 대한치과보철학회지

PURPOSE: This study evaluated color stability of Dentca 3D-printed denture teeth, in comparison to color stabilities of four conventional types of denture teeth, upon being immersed in various colorants.MATERIALS AND METHODS: Four types of conventional prefabricated denture teeth (Surpass, GC, Artic 6, Heraeus Kulzer, Premium 6, Heraeus Kulzer, Preference, Candulor), 3D-printed denture teeth (Dentca); and Z250 (Filtek Z250, 3M ESPE) were prepared for testing. The samples were immersed in erythrosine 3%, coffee, cola, and distilled water (DW) at 37℃. Color change (ΔE) was measured by spectrophotometer before immersion and at 7, 14, and 21 days after immersion. One-way analysis of variance was performed along with Tukey's honestly significant difference multiple comparisons test (P<.05).RESULTS: No great difference was observed between the color change of Dentca denture teeth and that of conventional denture teeth in most cases (P>.05). The color change of Dentca denture teeth immersed in erythrosine 3% was greater than that of Surpass (ΔE = 0.67 ± 0.25) after 1 week; Artic 6 (ΔE = 1.44 ± 0.38) and Premium 6 (ΔE = 1.69 ± 0.35) after 2 weeks; and Surpass (ΔE = 1.79 ± 0.49), Artic 6 (ΔE = 2.07 ± 0.21), Premium 6 (ΔE = 2.03 ± 0.75), and Preference (ΔE = 2.01 ± 0.75) after 3 weeks (P<.05).CONCLUSION: A color change was observed in Dentca denture teeth when immersed in some colorants; however, the maximum value of ΔE for Dentca denture teeth was within the clinically acceptable range.

Susceptibility of Mutans streptococci in the Planktonic and Biofilm State to Erythrosine / 대한소아치과학회지

The aim of this study was to investigate the susceptibility of Mutans streptococci in both planktonic and biofilm states to erythrosine.S. mutans was cultured in brain-heart infusion (BHI) broth. Erythrosine was diluted in BHI broth and prepared at a concentration range of 0.02 – 10000 µg/L. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were measured using the microdilution method. After forming biofilms on 96-well plates, the minimum biofilm inhibitory concentration (MBIC) and minimum biofilm eradication concentration (MBEC) were measured.S. mutans was susceptible to erythrosine in both planktonic and biofilm states. MIC and MBC values were both 19.5 µg/L for the planktonic state, while MBIC and MBEC values were 313 µg/L and 2500 µg/L, respectively, for the biofilm state.Erythrosine (19.5 µg/L) exhibited a bactericidal effect on S. mutans (killing 99.9%) in the planktonic state. For biofilms, erythrosine inhibited biofilm growth and eradicated 99.9% of biofilm bacteria at higher concentrations than MIC and MBC. These MBIC and MBEC concentrations are much lower than known noxious doses, and the MIC, MBC, and MBIC values were even lower than clinical concentrations.

Antimicrobial effect of toothbrush with light emitting diode on dental biofilm attached to zirconia surface: an in vitro study

PURPOSE: The purpose of this study was to evaluate the antimicrobial effects of a toothbrush with light-emitting diodes (LEDs) on periodontitis-associated dental biofilm attached to a zirconia surface by static and dynamic methods. MATERIALS AND METHODS: Zirconia disks (12 mm diameter, 2.5 mm thickness) were inserted into a 24-well plate (static method) or inside a Center for Disease Control and Prevention (CDC) biofilm reactor (dynamic method) to form dental biofilms using Streptococcus gordonii and Fusobacterium nucleatum. The disks with biofilm were subdivided into five treatment groups-control, commercial photodynamic therapy (PDT), toothbrush alone (B), brush with LED (BL), and brush with LED+erythrosine (BLE). After treatment, the disks were agitated to detach the bacteria, and the resulting solutions were spread directly on selective agar. The number of viable bacteria and percentage of bacterial reduction were determined from colony counts. Scanning electron microscopy (SEM) was performed to visualize alterations in bacterial morphology. RESULTS: No significant difference in biofilm formation was observed between dynamic and static methods. A significant difference was observed in the number of viable bacteria between the control and all experimental groups (P < 0.05). The percentage of bacterial reduction in the BLE group was significantly higher than in the other treated groups (P < 0.05). SEM revealed damaged bacterial cell walls in the PDT, BL, and BLE groups, but intact cell walls in the control and B groups. CONCLUSION: The findings suggest that an LED toothbrush with erythrosine is more effective than other treatments in reducing the viability of periodontitis-associated bacteria attached to zirconia in vitro.

Efficacy of an LED toothbrush on a Porphyromonas gingivalis biofilm on a sandblasted and acid-etched titanium surface: an in vitro study

PURPOSE: The aim of this study was to evaluate the antimicrobial effect of a newly devised toothbrush with light-emitting diodes (LEDs) on Porphyromonas gingivalis attached to sandblasted and acid-etched titanium surfaces. METHODS: The study included a control group, a commercial photodynamic therapy (PDT) group, and 3 test groups (B, BL, and BLE). The disks in the PDT group were placed in methylene blue and then irradiated with a diode laser. The B disks were only brushed, the BL disks were brushed with an LED toothbrush, and the BLE disks were placed into erythrosine and then brushed with an LED toothbrush. After the different treatments, bacteria were detached from the disks and spread on selective agar. The number of viable bacteria and percentage of bacterial reduction were determined from colony counts. Scanning electron microscopy was performed to visualize bacterial alterations. RESULTS: The number of viable bacteria in the BLE group was significantly lower than that in the other groups (P < 0.05). Scanning electron microscopy showed that bacterial cell walls were intact in the control and B groups, but changed after commercial PDT and LED exposure. CONCLUSIONS: The findings suggest that an LED toothbrush with erythrosine treatment was more effective than a commercial PDT kit in reducing the number of P. gingivalis cells attached to surface-modified titanium in vitro.

Antimicrobial Effect on Streptococcus mutans in Photodynamic Therapy using Different Light Source / 대한소아치과학회지

In a photodynamic therapy, the difference of antibacterial capacity was compared according to the type of source of light when the same quantity of energy is irradiated.After S. mutans is formed in planktonic state and biofilm state, erythrosine diluted to 40 µM was treated for 3 minutes, and as the type of light source, Halogen, LED, and Plasma arc were used, which were irradiated for 30 seconds, 15 seconds and 9.5 seconds, respectively.After the completion of the experiment, CFU of each experiment arm was measured to compare the photodynamic therapeutic effects according to each condition.The CFU of each experiment arm had no statistically significant difference.Under the same quantity of energy, the photodynamic therapeutic effect can be said to be the same regardless of types of light source, which is a useful result in the clinical field with various light irradiators.

Inativação fotodinâmica em biofilme de Streptococcus mutans sobre bráquetes metálicos e cerâmicos: um estudo in vitro / Photodynamic inactivation of Streptococcus mutans biofilm on metal and ceramic brackets: a study in vitro

O trabalho in vitro avaliou a eficácia da inativação fotodinâmica (PDI) da eritrosina (E) e hematoporfirina IX (H), com 10 µM, utilizando LED azul, dose de 75 J/cm2 em células planctônicas e biofilme de S. mutans (UA 159). Suspensões padrões contendo107 células/mL foram preparadas e submetidas a diferentes condições experimentais: a) hematoporfirina IX e LED (H+L+); b) eritrosina eLED (E+L+); c) apenas LED (F-L+); d) tratamento somente com hematoporfirina IX (H+L-); e) somente com eritrosina (E+L-); e f) grupo controle, sem tratamento com fotossensibilizador (F) e sem a utilização de LED (F-L-). As cepas foram semeadas em ágar MSBS para contagem de unidades formadoras de colônias (UFC/mL). Na segunda parte do trabalho foi realizado a PDI em biofilme de S.mutans sobre bráquetes metálicos e cerâmicos, com H a 10 µM e LED azul. Os resultados foram submetidos à análise de variância e teste de Tukey (p<0,05) e demonstraram que a E sob efeito do LED(E+L+) não foi eficaz na PDI de células planctônicas, nos parâmetros usados (p=0,3644). No entanto, a H promoveu redução de 6,78 log10(p<0,0001), no grupo de tratamento (H+L+). A PDI com a associação da H e LED foi efetiva na redução de 100% de culturas planctônicas de S. mutans, porém o mesmo não foi observado na associação com a E, na dosimetria utilizada no experimento. A PDI no biofilme de S. mutans sobre bráquetes metálicos, com a H e LED não foi eficaz nos parâmetros utilizados (p=0,1023), no entanto, ocorreu diminuição significativa de 53% sobre bráquetes cerâmicos (p=0,004). A H IX modificada é promissora como agente fotossensibilizador a ser empregado na técnica de PDI em associação ao LED azul, sendo necessários outros ensaios, em novas concentrações e/ou dosimetrias para se conseguir a inativação bacteriana

The in vitro study evaluated the efficacy of photodynamic inactivation(PDI) with erythrosine (E) and hematoporphyrin (H) 10 µM, using ablue light-emitting diode (LED), a fluence of 75 J/cm2, on planktoniccultures and biofilm of S. mutans (UA 159). Suspensions containing107 cells/mL were prepared and were tested under differentexperimental conditions: a) hematoporphyrin IX and LED (H+L+); b)erythrosine and LED irradiation (E+L+); c) only LED (P-L+); d)only hematoporphyrin IX (H+L-); e) only erythrosine (E+L-); and f)control group, no LED irradiation or photosensitizer (P) treatment(P-L-). After treatment, the strains were seeded onto MSBS agar inorder to determine the number of colony-forming units (CFU/mL).The second part of this work consisted of the PDI of S. mutans biofilmon metal and ceramic brackets with the H 10 μM and blue LED. Theresults were submitted to analysis of variance and the Tukey test(p<0.05) and showed that E under the effect of LED proved to beineffective in the PDI of planktonic cultures with the parameters used(p=0.3644). H, however, caused a reduction of 6.78 log10 (p<0.0001)in the treatment group (H+L+). PDI with H and LED exertedantimicrobial effect of 100% of the S. mutans strain studied, whereasthe same was not observed in the association with E in the dosimetryused in this work. PDI on S. mutans biofilm on metal brackets, with Hand LED was not effective with the parameters used (p=0.1023), however on ceramic brackets caused a significant reduction of 53%(p=0,004). Modified H IX is a promising photosensitizer to be used inthe PDI technique in combination with blue LED. Therefore, new testswith new concentrations and/or dosimetry are needed to achievebacterial inactivation

Inativação fotodinâmica em biofilme de Streptococcus mutans sobre bráquetes metálicos e cerâmicos: um estudo in vitro / Photodynamic inactivation of Streptococcus mutans biofilm on metal and ceramic brackets: a study in vitro

O trabalho in vitro avaliou a eficácia da inativação fotodinâmica (PDI) da eritrosina (E) e hematoporfirina IX (H), com 10 µM, utilizando LED azul, dose de 75 J/cm2 em células planctônicas e biofilme de S. mutans (UA 159). Suspensões padrões contendo107 células/mL foram preparadas e submetidas a diferentes condições experimentais: a) hematoporfirina IX e LED (H+L+); b) eritrosina eLED (E+L+); c) apenas LED (F-L+); d) tratamento somente com hematoporfirina IX (H+L-); e) somente com eritrosina (E+L-); e f) grupo controle, sem tratamento com fotossensibilizador (F) e sem a utilização de LED (F-L-). As cepas foram semeadas em ágar MSBS para contagem de unidades formadoras de colônias (UFC/mL). Na segunda parte do trabalho foi realizado a PDI em biofilme de S.mutans sobre bráquetes metálicos e cerâmicos, com H a 10 µM e LED azul. Os resultados foram submetidos à análise de variância e teste de Tukey (p<0,05) e demonstraram que a E sob efeito do LED(E+L+) não foi eficaz na PDI de células planctônicas, nos parâmetros usados (p=0,3644). No entanto, a H promoveu redução de 6,78 log10(p<0,0001), no grupo de tratamento (H+L+). A PDI com a associação da H e LED foi efetiva na redução de 100% de culturas planctônicas de S. mutans, porém o mesmo não foi observado na associação com a E, na dosimetria utilizada no experimento. A PDI no biofilme de S. mutans sobre bráquetes metálicos, com a H e LED não foi eficaz nos parâmetros utilizados (p=0,1023), no entanto, ocorreu diminuição significativa de 53% sobre bráquetes cerâmicos (p=0,004). A H IX modificada é promissora como agente fotossensibilizador a ser empregado na técnica de PDI em associação ao LED azul, sendo necessários outros ensaios, em novas concentrações e/ou dosimetrias para se conseguir a inativação bacteriana.

The in vitro study evaluated the efficacy of photodynamic inactivation(PDI) with erythrosine (E) and hematoporphyrin (H) 10 µM, using ablue light-emitting diode (LED), a fluence of 75 J/cm2, on planktoniccultures and biofilm of S. mutans (UA 159). Suspensions containing107 cells/mL were prepared and were tested under differentexperimental conditions: a) hematoporphyrin IX and LED (H+L+); b)erythrosine and LED irradiation (E+L+); c) only LED (P-L+); d)only hematoporphyrin IX (H+L-); e) only erythrosine (E+L-); and f)control group, no LED irradiation or photosensitizer (P) treatment(P-L-). After treatment, the strains were seeded onto MSBS agar inorder to determine the number of colony-forming units (CFU/mL).The second part of this work consisted of the PDI of S. mutans biofilmon metal and ceramic brackets with the H 10 μM and blue LED. Theresults were submitted to analysis of variance and the Tukey test(p<0.05) and showed that E under the effect of LED proved to beineffective in the PDI of planktonic cultures with the parameters used(p=0.3644). H, however, caused a reduction of 6.78 log10 (p<0.0001)in the treatment group (H+L+). PDI with H and LED exertedantimicrobial effect of 100% of the S. mutans strain studied, whereasthe same was not observed in the association with E in the dosimetryused in this work. PDI on S. mutans biofilm on metal brackets, with Hand LED was not effective with the parameters used (p=0.1023), however on ceramic brackets caused a significant reduction of 53%(p=0,004). Modified H IX is a promising photosensitizer to be used inthe PDI technique in combination with blue LED. Therefore, new testswith new concentrations and/or dosimetry are needed to achievebacterial inactivation.

Correlation of Vascular Endothelial Growth Factor Production with Photochemical Reaction-induced Retinal Edema / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Retinal edema is the major complication of retinal vein occlusion and diabetic retinopathy; it can damage visual function by influencing macular region. This study was to establish a rat retinal edema model and explore the related VEGF expression and observe the responses to anti-VEGF drugs in this model.</p><p><b>METHODS</b>A rat retinal edema model was established by inducing photochemical reaction using a 532 nm laser after the intravenous injection of Erythrosin B. Immediately after the laser treatment, models were given intravitreal injections of Ranibizumab or Conbercept to inhibit VEGF expression, and the changes of retinal thickness were measured. Retinal edema was observed using fundus photography (FP), optical coherence tomography (OCT), and fluoresce in fundus angiography (FFA) at 0, 1, 2, 4, 7 and 14 days after intervention. The retinal VEGF expression was measured using enzyme-linked immunosorbent assay (ELISA) and western blotting at each time point. The rat retinal edema model was also used to verify the function of anti-VEGF polypeptide ZY1.</p><p><b>RESULTS</b>Both retinal edema and vascular leakage were clearly observed at 1, 2 and 4 days after photochemical induction and the retinal thickness increased notably over the same period. The retinal VEGF expression peaked at day 1 and retina became thickening simultaneously. After the interventions, the VEGF expression of the Ranibizumab and Conbercept groups decreased at each time point compared to the edema group (26.90 ± 3.57 vs. 40.29 ± 6.68, F = 31.269 on day 1 and 22.36 ± 1.12 vs. 29.92 ± 0.93 F = 163.789 on day 2, both P < 0.01); the mean RT (278 ± 4 vs. 288 ± 3, F = 134.190 on day 1 and 274 ± 7 vs. 284 ± 6, F = 64.367 on day 2, both P < 0.05) and vascular leakage in these groups also decreased. The same results were observed in the ZY1 group, particularly at day 2 (P < 0.05).</p><p><b>CONCLUSIONS</b>This retinal edema model induced by a photochemical reaction is reliable and repeatable. Induced edema increases expression of VEGF. This model can be used to test new drugs.</p>

Postantibiotic Effects of Photodynamic Therapy Using Erythrosine and Light Emitting Diode on Streptococcus mutans

Dental caries, the most common oral disease, is a multifactorial disease caused by interactions among bacteria within the dental plaque, food, and saliva, resulting in tooth destruction. Streptococcus mutans has been strongly implicated as the causative organism in dental caries and is frequently isolated from human dental plaque. Photodynamic therapy (PDT) is a technique that involves the activation of photosensitizer by light in the presence of tissue oxygen, resulting in the production of reactive radicals capable of inducing cell death. Postantibiotic effect (PAE) is defined as the duration of suppressed bacterial growth following brief exposure to an antibiotic. In this study, the in vitro PAE of PDT using erythrosine and light emitting diode on S. mutans ATCC 25175 was investigated. The PAE of PDT for 1 s irradiation and 3 s irradiation were 1.65 h and 2.1 h, respectively. The present study thus confirmed PAE of PDT using erythrosine on S. mutans.

The effect of photodynamic therapy on Aggregatibacter actinomycetemcomitans attached to surface-modified titanium

PURPOSE: The purpose of this study was to evaluate the effect of photodynamic therapy (PDT) using erythrosine and a green light emitting diode (LED) light source on biofilms of Aggregatibacter actinomycetemcomitans attached to resorbable blasted media (RBM) and sandblasted, large-grit, acid-etched (SLA) titanium surfaces in vitro. METHODS: RBM and SLA disks were subdivided into four groups, including one control group and three test groups (referred to as E0, E30, E60), in order to evaluate the effect of PDT on each surface. The E0 group was put into 500 microL of 20 microM erythrosine for 60 seconds without irradiation, the E30 group was put into erythrosine for 60 seconds and was then irradiated with a LED for 30 seconds, and the E60 group was put into erythrosine for 60 seconds and then irradiated with a LED for 60 seconds. After PDT, sonication was performed in order to detach the bacteria, the plates were incubated under anaerobic conditions on brucella blood agar plates for 72 hours at 37degrees C, and the number of colony-forming units (CFUs) was determined. RESULTS: Significant differences were found between the control group and the E30 and E60 groups (P<0.05). A significantly lower quantity of CFU/mL was found in the E30 and E60 groups on both titanium disk surfaces. In confocal scanning laser microscopy images, increased bacterial death was observed when disks were irradiated for a longer period of time. CONCLUSIONS: These findings suggest that PDT using erythrosine and a green LED is effective in reducing the viability of A. actinomycetemcomitans attached to surface-modified titanium in vitro.

Photodynamic bactericidal effect against Enterococcus faecalis by erythrosine concentration and LED irradiation times / 대한구강보건학회지

OBJECTIVES: The purpose of this study was to provide photodynamic bactericidal effect against Enterococcus faecalis by erythrosine concentrations and LED irradiation times. METHODS: Erythrosine was used as a photosensitizer and green LED (3 Watt, 520-530 nm) was used as light source. E. faecalis ATCC 1943 and E. faecalis ATCC 29212 were used in this study. Approximately 10(5) CFU of bacteria were added in wells of a 96-well microtitration plate. For examining the effects of concentrations of erythrosine, 0, 0.625, 1.25, 2.5, 5, and 10 microM of erythrosine were added in wells containing bacteria. The irradiation time with LED was 30 sec. In another set of experiment, the effect of irradiation time for killing of bacteria was investigated by increasing irradiation time from 0 to 30 s with 10 microM of erythrosine final concentration. After irradiation, each sample was serially diluted with PBS and 50 microl of diluents was spread on duplicate blood agar plates. The plates were incubated for 72 h at 37degrees C under aerobic conditions and the number of CFU was determined. The experiments were repeated four times. The results were analyzed using one-way ANOVA, and Tukey's multiple comparison at a significance level of 0.05. RESULTS: When the erythrosine concentrations were more than 2.5 microM, E. faecalis ATCC 29212 was significantly decreased (P<0.05). The more erythrosine concentrations increased, the more E. faecalis ATCC 1943 decreased statistically significantly (P<0.05). In another set of experiment, when LED irradiation time was more than 20 s, E. faecalis ATCC 1943 decreased significantly (P<0.05), and if the irradiation times was more than 5 s, E. faecalis ATCC 29212 decreased significantly (P<0.05). CONCLUSIONS: PDT using erythrosine and green LED was found to be an effective method in killing E. faecalis.

The Effect of Erythrosine-mediated Photodynamic Therapy on Intraorally Formed Biofilm on Titanium Surface

The purpose of this study was to assess the efficacy of photodynamic therapy (PDT) using erythrosine and a halogen light source to treat a biofilm formed on a machined surface titanium disk in vivo. Ten volunteers carried an acrylic appliance containing six machined surface titanium disks on the upper jaw over a period of five days. After the five days of biofilm formation period, the disks were removed. PDT using 20 microM erythrosine and halogen light was then applied to the biofilms formed on the disks. Experimental samples were divided into a negative control group (no erythrosine and no irradiation), E0 group (erythrosine 60s + no irradiation), E30 group (erythrosine 60s + halogen light 30s), and E60 group (erythrosine 60s + halogen light 60s). Following PDT, the bacteria in the biofilm were found to be detached from each disk. Each suspension with detached bacteria were diluted and cultivated on a blood-agar plate for five days under anaerobic conditions. The cultivated bacterial counts in the E60 group were significantly lower than the control group (86.4%) or E0 group (76.7%). In the experimental groups also, the light exposure time and bacterial counts showed a negative correlation. In conclusion, PDT using erythrosine and halogen light has bactericidal effects on biofilms formed on a titanium disk in vivo. Notably, applying 20 microM erythrosine and 60 seconds of halogen light irradiation had a significantly potent effect.

The photodynamic therapy on Streptococcus mutans biofilms using erythrosine and dental halogen curing unit / 国际口腔科学杂志·英文版

The purpose of our study was to evaluate the effect of photodynamic therapy (PDT), using erythrosine as a photosensitizing agent and a dental halogen curing unit as a light source, on Streptococcus mutans in a biofilm phase. The S. mutans biofilms were formed in a 24-well cell culture cluster. Test groups consisted of biofilms divided into four groups: group 1: no photosensitizer or light irradiation treatment (control group); group 2: photosensitizer treatment alone; group 3: light irradiation alone; group 4: photosensitizer treatment and light irradiation. After treatments, the numbers of colony-forming unit (CFU) were counted and samples were examined by confocal laser scanning fluorescence microscopy (CLSM). Only group 4 (combined treatment) resulted in significant increases in cell death, with rates of 75% and 55% after 8 h of incubation, and 74% and 42% at 12 h, for biofilms formed in brain-heart infusion (BHI) broth supplemented with 0% or 0.1% sucrose, respectively. Therefore, PDT of S. mutans biofilms using a combination of erythrosine and a dental halogen curing unit, both widely used in dental clinics, resulted in a significant increase in cell death. The PDT effects are decreased in biofilms that form in the presence of sucrose.

Comparison of photodynamic bactericidal effects of erythrosine against Streptococcus mutans and Streptococcus sobrinus by different wavelength of LED lights / 대한구강보건학회지

No abstract available.

Susceptibility of planktonic cultures of Streptococcus mutans to photodynamic therapy with a light-emitting diode

The objective of this study was to evaluate the effect of photodynamic therapy with erythrosine and rose bengal using a light-emitting diode (LED) on planktonic cultures of S. mutans. Ten S. mutans strains, including nine clinical strains and one reference strain (ATCC 35688), were used. Suspensions containing 10(6) cells/mL were prepared for each strain and were tested under different experimental conditions: a) LED irradiation in the presence of rose bengal as a photosensitizer (RB+L+); b) LED irradiation in the presence of erythrosine as a photosensitizer (E+L+); c) LED irradiation only (P-L+); d) treatment with rose bengal only (RB+L-); e) treatment with erythrosine only (E+L-); and f) no LED irradiation or photosensitizer treatment, which served as a control group (P-L-). After treatment, the strains were seeded onto BHI agar for determination of the number of colony-forming units (CFU/mL). The results were submitted to analysis of variance and the Tukey test (p < 0.05). The number of CFU/mL was significantly lower in the groups submitted to photodynamic therapy (RB+L+ and E+L+) compared to control (P-L-), with a reduction of 6.86 log10 in the RB+L+ group and of 5.16 log10 in the E+L+ group. Photodynamic therapy with rose bengal and erythrosine exerted an antimicrobial effect on all S. mutans strains studied.

Photoinactivation of escherichia coli using xanthene dyes andlight-emitting diodes / Fotoinativação de escherichia coli utilizando corantes xantenos e diodo emissor de luz

The development of antibiotic resistance by pathogenic bacteria is currently one of the major problems in medicine. There fore, the study of new treatment modalities such as photodynamic therapy is important. The aim was to evaluate the effects of the Rose Bengal and erythrosine dye combined with a light-emitting diode (LED) on Escherichia coli. An E. coli suspension was prepared from a clinical strain and subjected to the following treatments: LED and Rose Bengal, LED and erythrosin, LED and physiological solution, and physiological solution only as control, and exposure to light for 60, 120 and 180 seconds. After incubation at 37°C for 24 h, the number of colony-forming units (CFU) was calculated and submitted to analysis of variance (ANOVA). Photodynamic therapy using Rose Bengal resulted in a reduction of 5.58 log10 in the number of CFU/mL after light exposure for 60 s and complete elimination after 180 s. However, photodynamic therapy using erythrosin only caused a slight reduction in the number of CFU/ml (0.30 log10)compared to the control group. The use of the LED alone had no toxic effect on the strain tested. In conclusion, Rose Bengal was more effective than erythrosin in photodynamic therapy against E. coli.

O desenvolvimento de resistência aos antibióticos por bactérias patogênicas é um dos maiores problemas da medicina atual. Assim, torna-se importante o estudo de novas modalidades de tratamento, como a terapia fotodinâmica. O objetivo deste estudo foi avaliar os efeitos dos fotos sensibilizadores rosa bengal e eritrosina associados a um diodo emissor de luz (LED) sobre Escherichia coli. Foi preparada uma suspensão padronizada de E. coli (106 células/mL) a partir de uma cepa clínica isolada da cavidade bucal humana. Essa cepa foi submetida aos seguintes tratamentos: laser e rosa bengal (L+RB+), laser e eritrosina (L+E+), laser e solução fisiológica (L+F-) e apenas solução fisiológica como controle (LF-) nos tempos de 60, 120 e 180 segundos de exposição à luz. Foi utilizado LED emissor de luz azul (460 nm), rosabengal e eritrosina na concentração de 50 μM. A seguir, foram realizadas culturas em ágar Infuso Cérebro-Coração para a contagem de unidades formadoras de colônias (UFC/mL) e os dados submetidos à análise de variância. A terapia fotodinâmica utilizando rosa bengal foi capaz de reduzir o número de UFC/mL de 5,58 log10 no tempo de exposição do LED de 60 seg até eliminação completa do microrganismo no tempo de 180 seg. Entretanto, a terapia fotodinâmica com eritrosina apresentou discreta redução do número de UFC/mL (0,30 log10) quando comparada ao grupo controle.O uso isolado do LED não apresentou toxicidade para as cepas testadas. Concluiu-se que o Rosa Bengal foi mais eficaz do que a eritrosina como fotossensibilizador na terapia fotodinâmica sobre Escherichia coli.

Characterization of erythrosine B binding to bovine serum albumin and bilirubin displacement.

The interaction of erythrosine B (ErB), a commonly used dye for coloring foods and drinks, with bovine serum albumin (BSA) was investigated both in the absence and presence of bilirubin (BR) using absorption and absorption difference spectroscopy. ErB binding to BSA was reflected from a significant red shift of 11 nm in the absorption maximum of ErB (527 nm) with the change in absorbance at λmax. Analysis of absorption difference spectroscopic titration results of BSA with increasing concentrations of ErB using Benesi-Hildebrand equation gave the association constant, K as 6.9 104 M-1. BR displacing action of ErB was revealed by a significant blue shift in the absorption maximum, accompanied by a decrease in absorbance difference at λmax in the difference spectrum of BR-BSA complex upon addition of increasing concentrations of ErB. This was further substantiated by fluorescence spectroscopy, as addition of increasing concentrations of ErB to BR-BSA complex caused a significant decrease in fluorescence at 510 nm. The results suggest that ErB binds to a site in the vicinity of BR binding site on BSA. Therefore, intake of ErB may increase the risk of hyperbilirubinemia in the healthy subjects.

Comparison of two different cleansing solutions in surface bacterial plaque removal from removable orthodontic appliances

The presence of microbial plaque not only can cause unpleasant appearance but it can also cause oral tissue inflammation, malodor as well as digestive system and respiratory tract infection. The aim of this study was to evaluate the efficacy of lemon juice 10% and effervescent cleanser tablet, in removing microbial plaque from the surface of removable orthodontic appliances. This study was conducted by using interventional design. Total of 30 patients were randomly selected regardless of their gender status. They were between 9-14 years old [mean age 12] and had maxillary removable orthodontic appliances. Initially, all the removable appliances were cleaned thoroughly using ultrasonic device. Patients were instructed to come back in four days. During this period, patients were not allowed to use any kind of mouthwash or other oral hygiene products to clean their appliances. On the first recall appointment, the removable appliances were first placed in Erythrosine solution for 7 minutes and they were scored for the amount of microbial plaque present. These appliances were rescored after immersing into 10% lemon juice solution for 30 minutes. The ultrasonic device was used to clean appliances before returning them to patients. A 4 day recall visit was scheduled for patients. The same plaque scoring procedure was conducted in the second appointment. This time, the appliances were immersed in a solution containing effervescent tablet for 30 minutes.This process was repeated two times in order to increase data validity. After completion of data collection, analysis was conducted using Sign Rank test. The plaque scores were decreased in 33 percent of cases [n = 10] after using the first method [10% Lemon Juice]; but there was no change observed in 66 percent of cases [n = 20] [P = 0.002]. When using the second method [effervescent tablet], although plaque scores slightly decreased in all cases, the complete removal of plaque were observed in 36.6 percent of the patients [n = l1] only [P < 0.001]. The score comparison between the two methods revealed that 93.4 percent of the cases [n = 28] showed less plaque when using the second method [effervescent tablet] [P < 0.001]. The 10% Lemon Juice solution has little effect on reducing the microbial plaque. However, the solution made out of effervescent cleanser tablet is more effective than 10% Lemon Juice solution in removing microbial plaque from removable orthodontic appliances

The effect of ultrasonic cleaning on the elimination of postoperative residual protein from the proseal(TM) laryngeal mask airway / 대한마취과학회지

BACKGROUND: Reusable Proseal(TM) laryngeal mask airways (PLMAs) can act as a vector for the transmission of prion diseases such as variant Creutzfeldt-Jacob disease. This study tested the hypothesis that supplementary ultrasonic cleaning facilitates the removal of protein deposits on PLMAs after anesthesia. METHODS: After clinical use, 40 PLMAs were randomly allocated into two groups. In the first group, the PLMAs were washed by hand and were then subsequently placed in an autoclave at 134degrees C for 40 min (Group 1, n = 20). In the second group, the PLMAs were washed by hand and ultrasonic cleaning using an enzymatic solution for 5 min, and were then subsequently placed in an autoclave (Group 2, n = 20). In both groups, protein deposits were detected on PLMAs by erythrosin staining. A staining score designated as none (0%), mild (0-20%), moderate (20-80%) and severe (80-100%), was assigned to each site (outer surface, inner surface and edges of the cuff, airway and drain tube, finger strap) according to the percentage of the stained surface area. RESULTS: Despite the cleaning of the masks, residual protein was found on the outer surface, inner surface and edge of the cuff, airway and drain tube, and finger strap of the PLMAs in both groups. Similar scores were observed for each part of the cleaned PLMAs in both groups, except for the outer surface of the PLMAs in Group 2 (P < 0.05). CONCLUSIONS: We conclude that the use of an ultrasonic cleaner with an enzymatic solution may be effective to cleanse the outer surface of the PLMAs, but there were no differences in the total scores for both groups.