The effects of antimicrobial photodynamic therapy (aPDT) with nanotechnology-applied curcumin and 450nm blue led irradiation on multi-species biofilms in root canals.

This study aimed to evaluate the effectiveness of antimicrobial photodynamic therapy (aPDT) utilizing nanotechnology-applied curcumin activated by blue LED (450 nm) on the elimination of microorganisms arranged in multispecies biofilms inside the root canals of extracted human teeth. Forty single-rooted human teeth were used; these were randomized into four experimental groups, each comprising 10 teeth: control group, no treatment; photosensitizer (PS) group, nanotechnology-applied curcumin alone; light group, blue LED used separately; and aPDT group, nanotechnology-applied curcumin activated by blue LED. To carry out the tests, the interiors of the root canals were inoculated with species of Candida albicans (ATCC 90029), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 25922), and methicillin-resistant Staphylococcus aureus (MRSA) (ATCC 43300), using a multispecies biofilm. After the incubation period, the canals were treated according to the experimental groups, with no treatment given in the control group. Studied inasmuch as the antimicrobial effectiveness of aPDT was concerned, it was observed that the greatest reduction in microbial counts using aPDTs was achieved against MRSA (mean reduction = 2.48 Log10 CFU/mL), followed by Escherichia coli (mean reduction = 1.72), and Enterococcus faecalis (mean reduction = 1.65); a reduction greater than 1.5 Log10 CFU/mL showed relevant effectiveness of aPDT against these microorganisms. Of note, aPDT has also shown considerable effectiveness against Candida albicans (mean reduction = 0.71), with a statistical difference in the reduction between the groups. aPDT was effective in reducing all microorganisms examined. The average reduction was greater than 1.5 Log10 in all microorganisms except for Candida albicans. HIGHLIGHTS: • aPDT was a viable treatment for root canals; • Nanotechnological curcumin aPDT was effective in reducing multispecies biofilm microorganisms; • aPDT technique showed efficacy under the worst microbiological conditions , such as mature multispecies biofilm; • Nanotechnological curcumin aPDT was able to reduce Gram positive, negative bacterial and yeasts in root canals.

Characterization of Brazilian green propolis as a photosensitizer for LED light-induced antimicrobial photodynamic therapy (aPDT) against methicillin-resistant Staphylococcus aureus (MRSA) and Vancomycin-intermediate Staphylococcus aureus (VISA).

Staphylococcus aureus is the primary cause of skin and soft tissue infections. Its significant adaptability and the development of resistance are the main factors linked to its spread and the challenges in its treatment. Antimicrobial photodynamic therapy emerges as a promising alternative. This work aimed to characterize the antimicrobial photodynamic activity of Brazilian green propolis, along with the key bioactive compounds associated with this activity. Initially, a scanning spectrometry was conducted to assess the wavelengths with the potential to activate green propolis. Subsequently, reference strains of methicillin-resistant Staphylococcus aureus (MRSA ATCC 43300) and vancomycin-intermediate Staphylococcus aureus (VISA ATCC 700699) were exposed to varying concentrations of green propolis: 1 µg/mL, 5 µg/mL, 10 µg/mL, 50 µg /mL and 100 µg/mL and were stimulated by blue, green or red LED light. Finally, high-performance liquid chromatography coupled with a diode array detector and tandem mass spectrometry techniques, along with classic molecular networking analysis, was performed to identify potential bioactive molecules with photodynamic activity. Brazilian green propolis exhibits a pronounced absorption peak and heightened photo-responsiveness when exposed to blue light within the range of 400 nm and 450 nm. This characteristic reveals noteworthy significant photodynamic activity against MRSA and VISA at concentrations from 5 µg/mL. Furthermore, the propolis comprises compounds like curcumin and other flavonoids sourced from flavone, which possess the potential for photodynamic activity and other antimicrobial functions. Consequently, Brazilian green propolis holds promise as an excellent bactericidal agent, displaying a synergistic antibacterial property enhanced by light-induced photodynamic effects.

Porphyrin-associated fluorescence spectroscopy (Photogen®) for the optical diagnosis of dental biofilm in orthodontic treatment: An observational clinical trial.

OBJECTIVE: This study assessed the presence of dental biofilm with fluorescence spectroscopy associated with porphyrin (Photogen®) in users of orthodontic appliances. METHODS: This cross-sectional observational clinical trial included 21 patients with metallic orthodontic fixed appliances. The presence of biofilm was evaluated by fluorescence spectroscopy (Evince-MMÓptics. São Carlos-SP, Brazil) with a porphyrin photo-evidence device (Photogen®). Digital images of the buccal surface of the upper anterior teeth (central and lateral incisors and canines) without and with porphyrin were analyzed using the histogram R (red) function in ImageJ software. The results were analyzed using the maximum and mode values of the red pixels from the histograms. The statistical analysis considered the significance level of 5%. RESULTS: The maximum values and modes of the red pixels were significantly higher in biofilms analyzed by porphyrin-associated optical spectroscopy compared to optical spectroscopy alone. CONCLUSIONS: Porphyrin-associated fluorescence spectroscopy was able to detect dental biofilm in the oral environment of patients with orthodontic treatment. This method better evidenced the presence of biofilm on the buccal surfaces of the upper teeth compared to that observed with fluorescence spectroscopy without porphyrin.

Comparative randomized trial study about the efficacy of photobiomodulation and curcumin antimicrobial photodynamic therapy as a coadjuvant treatment of oral mucositis in oncologic patients: antimicrobial, analgesic, and degree alteration effect.

INTRODUCTION: As conventional treatments currently available for mucositis are not considerably effective, there is a need to implement an adjuvant protocol for the treatment of oral mucositis in patients undergoing radiotherapy and chemotherapy. PURPOSE: To evaluate the effect of photobiomodulation (PBM) and antimicrobial photodynamic therapy (aPDT) mediated by curcumin and blue LED as an adjunct treatment of oral mucositis for oncology patients using chemotherapy and/or radiotherapy. METHODS: Clinical, randomized study, in a single location, in an oncology service of a general hospital, with a total of 30 patients (over 18 years old) with stable oral mucosa lesions in the process of chemotherapy and/or radiotherapy. The patients were divided into 3 groups: control group (treated with nystatin), PBM group (treated with low-level laser therapy), and the aPDT group (treated with 450-nm blue LED and curcumin photosensitizer). RESULTS: The results showed, by means of intra-group comparisons, that the two experimental treatments promoted yeast reduction of the genus Candida in the last two evaluations (21 days and 30 days), but not in the first two evaluations (7 days and 14 days). The intra-group comparisons showed that the control and aPDT group showed a significant difference in the degree of mucositis over the four evaluations performed, with the results pointing out that the mucositis worsened in the control group from the 14th day, while reduced in the aPDT group from the 21st day of treatment. CONCLUSION: A reduction in the degree of mucositis and pain score was observed in the PBM and aPDT groups, with the aPDT group standing out when presenting early clinical improvement in relation to the PBM group and the control group, thus emphasizing its effectiveness within the desired aspects. Regarding the antimicrobial effect, aPDT showed a greater reduction of yeasts of the genus Candida in the tested parameters.

Total mouth photodynamic therapy mediated by red LED and porphyrin in individuals with AIDS.

Due to the immune changes resulting from HIV/AIDS infection, systemic and local infections throughout the body are common. The use of high activity antiretroviral therapy has been widely used during treatment, which, added to the use of antibiotics, antifungals, and the patients' own immunocompromised state, cause important changes in the oral microbiota. The emergence of pathological microorganisms and with high resistance to drug therapies are frequent and cause serious damage to the oral health of these patients. In this sense, antimicrobial photodynamic therapy (aPDT) appears as a promising alternative in the control of these oral infections. The aim of the study was to test the effectiveness of a therapeutic protocol for total oral aPDT mediated by a 660-nm red LED (light-emitting diode) associated with porphyrin in individuals with AIDS. Patients were selected by exclusion criteria and randomly distributed into groups to test the effectiveness of antimicrobial aPDT with 50 µg/ml porphyrin associated with the red LED. Before and after the treatments, saliva samples were collected and processed in duplicate in selective culture media. Colonies were counted and the results obtained in Log10 CFU/ml and tested statistically. It was concluded that aPDT was effective in reducing oral enterobacteria, in addition to reducing Streptococcus spp. and general count of microorganisms, when considering the numbers of TCD4 and TCD8 lymphocytes.

Follow-up of pressure ulcer treatment with photodynamic therapy, low level laser therapy and cellulose membrane.

OBJECTIVE: A pressure ulcer (PU) is an area of tissue trauma caused by continuous and prolonged pressure, often associated with hospitalised patients immobilised due to neurological problems, negatively affecting their quality of life, and burdening the public budget. The aim of this study was to report the follow-up, for 45 weeks, of three patients with neurological lesions due to trauma who subsequently developed PUs, and who were treated with a combination of photodynamic therapy (PDT), low level laser therapy (LLLT) and cellulose membrane (CM). METHOD: PDT was mediated by the photosensitiser curcumin on a 1.5% emulsion base. Blue LED light at 450 nm was delivered continuously for 12 minutes at an irradiance of 30mW/cm2 and total energy delivered to the tissue was 22J/cm2. LLLT was performed with 660 nm laser, punctuated and continuous, twice a week with parameters: spot size 0.04cm2, power of 40mW, 10 seconds per point, fluence of 10J/cm2 and irradiance of 1000mW/cm2. RESULTS: All PUs had a significant reduction (range: 95.2-100%) of their area after 45 weeks of follow-up and two PUs had complete healing at 20 weeks and 30 weeks. All of the PUs showed a reduction in contamination with the PDT treatments in different proportions. CONCLUSION: From the results obtained, we conclude that the combination of PDT, LLLT and CM is a promising treatment for PU healing.

Photodynamic therapry with curcumin in the reduction of enterococcus faecalis biofilm in bone cavity: rMicrobiological and spectral fluorescense analysis.

BACKGROUND: Antimicrobial photodynamic therapy (PDT) has emerged as a therapeutic strategy to conventional procedures using antibiotics. OBJECTIVE: To evaluate the antimicrobial effectiveness of PDT using blue light emitting diode (LED) associated with curcumin on biofilms of Enterococcus faecalis in bovine bone cavities and also to analyze the presence of these biofilms through spectral fluorescence. MATERIALS AND METHODS: Standardized suspensions of E. faecalis (ATCC 29212) were incubated in artificial bone cavities for 14 days at 36 °C ± 1 °C for biofilm formation. The test specimens were distributed among the four experimental groups (n = 10): L-C- (control), L + C- (LED for 5 min), L-C+ (curcumin for 5 min) and L + C+ (PDT). Aliquots were collected from the bone cavities after treatments and seeded on BHI agar for 24 h at 36 °C ± 1 °C for CFU count. Before and after each treatment the specimens were submitted to spectral fluorescence, whose images were compared in the Image J program. The log10 CFU/mL results were submitted to the Kruskal-Wallis test (5%) and the biofilm fluorescence spectroscopy results were submitted to the Wilcoxon test (5%). RESULTS: All treatments presented statistical difference when compared to the control, and PDT was responsible for the largest reduction (1.92 log10 CFU/mL). There was a reduction in the fluorescence emitted after the treatments, with greater statistical difference in the PDT group. CONCLUSION: PDT was efficient in the reduction of E. faecalis biofilms. In all groups post treatment there was a significant reduction of biofilms in the fluorescence spectroscopy images with greater reduction in the PDT group.

Total mouth photodynamic therapy mediated by blue led and curcumin in individuals with AIDS.

OBJECTIVES: To test the effectiveness of an efficient therapeutic protocol for the total mouth antimicrobial photodynamic therapy (aPDT) mediated by 450 nm blue LED associated with curcumin in individuals with AIDS. METHODS: Patients were selected by exclusion criteria and randomly distributed in groups to test the effectiveness of antimicrobial aPDT with curcumin 0.75 mg/mL associated with the blue LED (67 mW/cm2, 20.1 J/cm2). Before and after the treatments, samples were collected from the saliva being processed in duplicate in selective culture media. The colonies were counted and the results obtained in log10 CFU/mL were statistically tested (T-paired statistical test, 5%). RESULTS: The log10 CFU/mL of Streptococcus spp., Staphylococcus spp., and total count of microorganisms showed statistically significant (p = 0.023; p = 0.001 and p = 0.017, respectively) reduction after treatment in patients with aPDT. CONCLUSION: aPDT was effective in reducing Streptococcusspp. in addition to reducing Staphylococcusspp., enterobacteria and the total count of microorganisms when considering the numbers of TCD4 and TCD8 lymphocytes. The aPDT in the studied protocol was able to control clinically important intraoral microorganisms for AIDS patients, both those with TCD4 lymphocytes above or below 25% of normal and those with TCD8 lymphocytes above 25% of normal.

Reduced methicillin-resistant Staphylococcus aureus biofilm formation in bone cavities by photodynamic therapy.

Photodynamic Therapy (PDT) is a promising alternative for the treatment of infectious bone lesions in the oral cavity. The objective of this study was to evaluate the antimicrobial effectiveness of PDT using blue LED associated with curcumin in methicillin-resistant Staphylococcus aureus biofilms (MRSA) in bovine bone cavities by fluorescence spectroscopy. Standardized suspensions of MRSA culture were inoculated into bone lesions to form biofilm. Forty bone species were distributed in three distinct groups: L-C- (control); L + C- (LED for 5 min); L-C+ (curcumin incubation for 5 min) and L + C+ (PDT). Aliquots of 100 µL were collected from the bone cavities after the treatments and were cultived in BHI for 24 h at 36 °C ±â€¯1 and bacterial colonies counting were performed. Statistical analysis were performed using the paired t-test and analysis of variance (ANOVA) for the variables studied. RESULTS: The control and PDT groups presented statistically significant differences (p < 0.001). It was possible to reduce 3.666 log10 CFU/mL of MRSA and a reduction in the fluorescence emitted after the treatments was observed. The MRSA reduction in biofilms by PDT was the most efficient treatmnent. There was a significant reduction of biofilms in the L + C- and non-PDT groups by fluorescence spectroscopy images.

Application of photodynamic therapy, laser therapy, and a cellulose membrane for calcaneal pressure ulcer treatment in a diabetic patient: A case report.

Diabetes mellitus is a metabolic disorder in which a person has high blood glucose levels due to inadequate insulin production by the pancreas. Wounds in these individuals cannot heal properly over time due to circulatory changes that hinder and stagnate the healing process. We report the case of an 82-year-old female type 2 diabetes mellitus carrier, presenting to clinical-dermatological examination pressure ulcer (PU) in the right calcaneus region. The patient was treated with photodynamic therapy using curcumin and blue light-emitting diodes (LEDs), laser therapy, and the application of a cellulose membrane in order to promote ulcer decontamination by local action, accelerate wound healing, and maintain favorable conditions of asepsis and moisture, respectively. The ulcer healing occurred after 30days of treatment and total epithelialization was observed. From the results obtained in this case report, we conclude that the combination of photodynamic therapy, laser therapy, and coating with a cellulose membrane is a promising treatment for the healing of PU in diabetic patients.

Photodynamic therapy controls of Staphylococcus aureus intradermal infection in mice.

Infections caused by Staphylococcus aureus lead to skin infections, as well as soft tissues and bone infections. Given the communal resistance to antibiotics developed by strains of this bacterium, photodynamic therapy emerges as a promising alternative treatment to control and cure infections. Females of the Balb/C mice were infected with 108 CFU of methicillin-resistant S. aureus (MRSA) and divided into four distinct groups: P-L- (negative control group), P+L- (group exposed only to curcumin), P-L+ (group exposed only to LED incidence of 450 nm, 75 mW/cm2, and 54 J/cm2 for 10 min), and P+L+ (group exposed to curcumin followed by 10 min of LED irradiation) (n = 24). The mice were euthanized 48 and 72 h after infection, and biologic materials were collected for analysis of the bacterial load, peripheral blood leukocyte counts, and draining lymph nodes cell counts. The normalization of data was checked and the ANOVA test was applied. The bacterial load in the draining lymph node of P+L+ group was lower when compared to the control groups 72 h post infection (p < 0.0001), indicating that the LED incidence associated with curcumin controls of the staphylococci intradermal infection. The number of the total lymph node cells shows to be lower than control groups in the two availed times (p < 0.01). The histological analysis and the counting of white blood cells did not show differences among cells in the blood and in the tissue of infection. This is the first report showing that photodynamic therapy may be effective against MRSA infection in a murine model of intradermal infection.

Effectiveness of photodynamic therapy on Candida species isolated from oral samples of children exposed and not exposed to HIV / Efetividade da terapia fotodinâmica sobre espécies de Candida isoladas de amostras bucais de crianças expostas e não expostas ao HIV

ABSTRACT Objective: Identify yeast species isolated from unexposed, exposed and HIV-carrier children, and verify the effectiveness of low power laser photodynamic therapy (PDT) on the yeasts species belonging to the Candida genus. Methods: Fifty children assisted by the Public Health Program of the city of Vitória da Conquista, Bahia, were selected and divided into three groups: unexposed to HIV, exposed to HIV during pregnancy, and HIV-carrier. Saliva samples were collected in a disposable sterile universal container and were plated to Sabouraud dextrose agar supplemented with 0.1 mg/mL chloramphenicol. The plates were incubated at 37°C for 48 h. Three strains of each patient were identified by using an API 20 C AUX system. The strains were submitted to photodynamic therapy (PDT) with a 660 nm low power laser and methylene blue dye at different times of irradiation (90, 180 and 282 sec.). Results: The results showed that the most prevalent species was Candida albicans followed by Candida famata (second most prevalent in unexposed to HIV and HIV carriers)) and Candida parapsilosis (second most prevalent in exposed to HIV group). The CFU/mL of Candida spp. decreased significantly (p<0,05) in all groups treated with PDT compared to the controls. Photodynamic therapy treatments at different exposure times (e.g., PS+L90+, PS+L180+, PS+L282+) revealed that the exposure time of 282 sec. gave the highest reduction of the mean logarithmic CFU/mL. Conclusion: Candida albicans was the most prevalent Candida species in these three groups and Candida non-albicans species, when combined, amounted to a significant percentage of Candida isolates. Photodynamic therapy was effective in inactivating the Candida spp. isolated from the oral cavity of children not exposed to HIV, exposed to HIV and HIV-carriers, with the best photodynamic therapy irradiation time being 282 sec.

RESUMO Objetivo: Identificar espécies de leveduras isoladas de crianças não expostas, expostas ao HIV e portadoras de AIDS, e verificar a eficácia da terapia fotodinâmica com laser de baixa potência sobre as espécies de leveduras pertencentes ao gênero Candida. Métodos: Cinquenta crianças atendidas pelo Programa de Saúde Pública da cidade de Vitória da Conquista, Bahia, foram selecionadas e divididas em três grupos: não expostas ao HIV, expostas ao HIV durante a gravidez e portadoras da AIDS. Amostras de saliva foram coletadas em um recipiente universal descartável estéril e foram semeadas em ágar Sabouraud dextrose suplementado com 0,1 mg / mL de cloranfenicol. As placas foram incubadas a 37°C durante 48h. Três cepas de cada paciente foram identificadas utilizando o sistema API 20 C AUX. As cepas foram submetidas à Terapia Fotodinâmica com laser de baixa potência de 660 nm e corante azul de metileno em diferentes tempos de irradiação (90, 180 e 282 segundos). Resultados: Os resultados mostraram que a espécie isolada mais prevalente nos grupos estuddos foi Candida albicans, seguida de Candida famata (segunda mais prevalene nos grupos não expostos ao HIV e com AIDS) e Candida parapsilosis (segunda mais prevalente no grupo exposto ao HIV). Houve diminuição significante de CFU/ml de Candida spp. (p <0,05) em todos os grupos tratados com terapia fotodinâmica, em comparação com os controles. A terapia fotodinâmica, nos diferentes tempos (e.g., PS+L90+, PS+L180+, PS+L282+) mostrou que o tempo de 282 seg. apresentou a maior redução em media de logarítmo de UFC/mL. Conclusão: Candida albicans foi a espécie de Candida mais prevalente isolada nos três grupos e as espécies de Candida não-albicans, quando combinadas, contribuíram com porcentagem significativa dos isolados de Candida. A PDT foi eficaz na inativação de Candida spp. isoladas a partir da cavidade oral de crianças não expostas, expostas ao HIV e portadoras da AIDS, com o melhor tempo de irradiação sendo o de 282 seg.

In vitro effectiveness of 455-nm blue LED to reduce the load of Staphylococcus aureus and Candida albicans biofilms in compact bone tissue.

The aim of this study was to evaluate the effectiveness of a 455-nm blue light-emitting diode (LED), at different application times, to reduce the load of Staphylococcus aureus and Candida albicans biofilms applied to compact bone tissue. The microorganisms S. aureus (ATCC 25923) and C. albicans (ATCC 18804) were used to form biofilms on 160 specimens of compact bones that had been divided into eight experimental groups (n = 10) for each microorganism, according to the times of application of the 455-nm blue LED (1, 2, 3, 4, 5, 7, and 10 min) with an irradiance of 75 mW/cm2. After LED application, decimal dilutions of microorganisms were performed, plated on BHI or Sabouraud agar and incubated for 24 h/35 °C to obtain CFU/mL counts. The findings were statistically analyzed using a ANOVA 5 %. For the group of S. aureus biofilms, all groups of 455-nm LED application differ compared with the control group (p < 0.05), in which no treatment was given. The largest reduction was obtained in the group receiving LED for 10 min (p = 0.00); within this group, a 3.2 log reduction was observed. For the C. albicans biofilms, only those samples receiving 3, 7, and 10 min of LED application presented a significant difference compared with the control group (p < 0.00), indicating that longer application times are required to achieve efficacy. The results of this study show that 455-nm LED light was effective to reduce the load of S. aureus and C. albicans biofilms, especially during 10 min of application.

Isolamento de leveduras do gênero Candida em amostras da cavidade bucal de crianças com paralisia cerebral / Isolation of Candida yeast in samples obtained from the oral cavity of children with cerebral palsy

Este trabalho teve como objetivo isolar e identificar leveduras do gêneroCandida isoladas de amostras bucais de crianças na faixa etária de 2 a 8 anos com paralisia cerebral, atendidas na associação de pais e amigos dos excepcionais (APAE) em um município do interior da Bahia e atendidas em unidade de saúde da família do mesmo município. Amostras de saliva de 20 crianças (2-8 anos) foram coletadas com auxílio de swabe encaminhadas para processamento no laboratório de Microbiologia onde foram semeadas em Agar Sabouraud Dextrose com cloranfenicol em duplicata e, em seguida, foram incubadas a 35°C±2/ 24h e mais 5 dias à temperatura ambiente para verificação de crescimento de unidades formadoras de colônia por mililitro (UFC.mL-1). Os dados obtidos em UFC.mL-1 foram transformados em logaritmo (Log) e submetidos tanto à análise descritiva quanto ao teste estatístico ANOVA (5%) para observação de diferenças de relevância estatística. Todos os isolados de amostra bucal de crianças do grupo com paralisia cerebral apresentaram positividade para espécies de leveduras do gênero Candida. No grupo de crianças com paralisia cerebral houve um maior isolamento de leveduras de gênero Candida (médialog = 1,8 UFC.mL-1) nas amostras bucais em relação ao grupo de crianças controle (médialog = 0,6 UFC.mL-1). Crianças portadoras de paralisia cerebral apresentam um índice aumentado de espécies de Candida na cavidade bucal que, juntamente com outras condições odontológicas peculiares, predispõem ao aparecimento de candidíases e requerem preparo da equipe de saúde bucal para obtenção de melhores resultados no tratamento direcionado a essa população...

This study aimed to isolate and identify Candida species from oral samples of 2-8 years children with cerebral palsy from the Association of Parents and Friends of Exceptional (APAE) and assisted at the family health unit at a town in the interior of Bahia. Saliva samples from 19 children were collected with a swab and sent for processing in the microbiology laboratory where they were plated on Sabouraud Dextrose Agar with chloramphenicol in duplicate and then incubated at 35°C±2 for 24h and then 5 days at room temperature to check the growth of colony-forming units per milliliter (UFC.mL-1). Data from UFC.mL-1 were transformed into logarithm (Log) and submitted to descriptive analysis and ANOVA (5%) to observe statistic differences. All oral isolates of children with cerebral palsy were positive for Candida yeast species. Greater isolation of Candida yeasts (medialog = 1.8 UFC.mL-1) was observed in the group of children with cerebral palsy when compared to control group (medialog = 0.6 UFC. mL-1). Children with cerebral palsy have an increased rate of Candida species in the oral cavity, along with other peculiar dental conditions that predispose to candidiasis. Thus proper training of the oral health team is required in order to achieve better results in the treatment of this population...

Sterilizing elastomeric chains without losing mechanical properties. Is it possible?

OBJECTIVE: To investigate the effects of different sterilization/disinfection methods on the mechanical properties of orthodontic elastomeric chains. METHODS: Segments of elastomeric chains with 5 links each were sent for sterilization by cobalt 60 (Co60) (20 KGy) gamma ray technology. After the procedure, the elastomeric chains were contaminated with clinical samples of Streptococcus mutans. Subsequently, the elastomeric chains were submitted to sterilization/disinfection tests carried out by means of different methods, forming six study groups, as follows: Group 1 (control - without contamination), Group 2 (70°GL alcohol), Group 3 (autoclave), Group 4 (ultraviolet), Group 5 (peracetic acid) and Group 6 (glutaraldehyde). After sterilization/disinfection, the effectiveness of these methods, by Colony forming units per mL (CFU/mL), and the mechanical properties of the material were assessed. Student's t-test was used to assess the number of CFUs while ANOVA and Tukey's test were used to assess elastic strength. RESULTS: Ultraviolet treatment was not completely effective for sterilization. No loss of mechanical properties occurred with the use of the different sterilization methods (p > 0.05). CONCLUSION: Biological control of elastomeric chains does not affect their mechanical properties.

Sterilizing elastomeric chains without losing mechanical properties. Is it possible?

OBJECTIVE: To investigate the effects of different sterilization/disinfection methods on the mechanical properties of orthodontic elastomeric chains. METHODS: Segments of elastomeric chains with 5 links each were sent for sterilization by cobalt 60 (Co60) (20 KGy) gamma ray technology. After the procedure, the elastomeric chains were contaminated with clinical samples of Streptococcus mutans. Subsequently, the elastomeric chains were submitted to sterilization/disinfection tests carried out by means of different methods, forming six study groups, as follows: Group 1 (control - without contamination), Group 2 (70°GL alcohol), Group 3 (autoclave), Group 4 (ultraviolet), Group 5 (peracetic acid) and Group 6 (glutaraldehyde). After sterilization/disinfection, the effectiveness of these methods, by Colony forming units per mL (CFU/mL), and the mechanical properties of the material were assessed. Student's t-test was used to assess the number of CFUs while ANOVA and Tukey's test were used to assess elastic strength. RESULTS: Ultraviolet treatment was not completely effective for sterilization. No loss of mechanical properties occurred with the use of the different sterilization methods (p > 0.05). CONCLUSION: Biological control of elastomeric chains does not affect their mechanical properties. .

OBJETIVO: verificar os efeitos de diferentes métodos de esterilização/desinfecção nas propriedades mecânicas de elásticos ortodônticos em cadeia. MÉTODOS: segmentos de elástico em cadeia com 5 elos cada foram enviados para esterilização em radiação gama com cobalto 60 (20 KGy). Após esterilização, esses foram contaminados com amostras clínicas de Streptococcus mutans. Passado esse período, foram submetidos aos testes de esterilização/desinfecção por diferentes métodos, formando seis grupos de estudo, assim denominados: Grupo 1 (controle - sem ter sido contaminado), Grupo 2 (álcool 70°GL), Grupo 3 (autoclave), Grupo 4 (ultravioleta), Grupo 5 (ácido peracético) e Grupo 6 (glutaraldeído). Após esterilização/desinfecção, avaliou-se a efetividade desses métodos, por meio de contagem de unidades formadoras de colônias por mL (UFC/mL), e as propriedades mecânicas desses materiais. Utilizou-se o teste t de Student para avaliar o número de UFC, além do ANOVA e, posteriormente, do teste de Tukey para avaliação da força. RESULTADOS: verificou-se que o ultravioleta não obteve eficácia total quanto à esterilização. E não ocorreu perda das propriedades mecânicas dos elásticos, com os diferentes métodos de esterilização utilizados (p > 0,05). CONCLUSÃO: o controle biológico de elásticos em cadeia não interfere nas suas propriedades mecânicas. .

Antimicrobial photodynamic inactivation of Staphylococcus aureus biofilms in bone specimens using methylene blue, toluidine blue ortho and malachite green: An in vitro study.

OBJECTIVE: To evaluate the in vitro effectiveness of APDI with a 660 nm laser combined with methylene blue (MB), toluidine blue ortho (TBO) and malachite green (MG) dyes to inactivate Staphylococcus aureus (ATCC 25923) biofilms in compact and cancellous bone specimens. METHODS: Eighty specimens of compact and 80 of cancellous bone were contaminated with a standard suspension of the microorganism and incubated for 14 days at 37°C to form biofilms. After this period, the specimens were divided into groups (n=10) according to established treatment: PS-L- (control - no treatment); PSmb+L-, PStbo+L-, PSmg+L- (only MB, TBO or MG for 5 min in the dark); PS-L+ (only laser irradiation for 180 s); and APDImb, APDItbo and APDImg (APDI with MB, TBO or MG for 180 s). The findings were statistically analyzed by ANOVA at 5% significance levels. RESULTS: All experimental treatments showed significant reduction of log CFU/mL S. aureus biofilms when compared with the control group for compact and cancellous bones specimens; the APDI group's treatment was more effective. The APDI carried out for the compact specimens showed better results when compared with cancellous specimens at all times of application. For the group of compact bone, APDImg showed greater reductions in CFU/mL (4.46 log 10). In the group of cancellous bone, the greatest reductions were found in the APDImb group (3.06 log 10). CONCLUSION: APDI with methylene blue, toluidine blue ortho and malachite green dyes and a 660 nm laser proved to be effective in the inactivation of S. aureus biofilms formed in compact and cancellous bone.

Prevalence of Candida yeasts in oral samples from children with AIDS and children exposed and not exposed to HIV served by SUS in the state of Bahia, Brazil / Prevalência de leveduras do gênero Candida em amostras bucais de crianças com AIDS, expostas e não-expostas ao HIV atendidas pelo SUS no interior da Bahia-Brasil

OBJECTIVE: This study aimed to determine the prevalence of Candida albicans and non-albicans yeast species isolated from oral samples of children with AIDS and of children exposed and not exposed to HIVduring pregnancy and served by the public health system in a county located in the interior of the state of Bahia, Brazil. METHODS: Saliva samples from 50 children aged between 2 and 12 years treated by SUS (group I = control group, group II = group exposed to HIV without seroconversion, and group III = AIDS carriers) were collected, seeded in Sabouraud dextrose agar with chloramphenicol, and fungal cultures were grown at 35 ± 2° C for 24 hours. Three isolated colonies were randomly selected from each individual plaque for identification using the API20 AUX Biomerieux® method. RESULTS: The most frequent fungal species in samples from children not exposed to HIV, exposed to HIV, and AIDS carriers was Candida albicans (48.80%, 25.64%, and 58.13%, respectively). Species of Candida non-albicans were also isolated from all groups studied. CONCLUSIONS: Despite the higher prevalence of Candida albicans in these groups, non-albicans species represented a significant percentage of Candida isolates. .

OBJETIVO: Verificar a prevalência de leveduras do gênero Candida albicans e não-albicans isoladas de amostras bucais de crianças com AIDS, expostas ao HIV durante o período gestacional e não-expostas ao HIV atendidas pelo sistema único de saúde em um município do interior da Bahia- Brasil. MÉTODOS: Para a realização do estudo foram coletadas amostras de saliva de 50 crianças entre 2 e 12 anos atendidas pelo SUS (grupo I = controle; grupo II = expostas ao HIV, sem soroconversão e grupo III = portadoras da AIDS),que após semeadas em ágar Sabouraud dextrose com cloranfenicol, foram incubadas a 35°C±2/ 24h para verificação de crescimento de colônias. Dessas foram selecionadas aleatoriamente 3 cepas, de cada indivíduo, para identificação pelo método API 20 AUX da Biomerieux®. RESULTADOS: A espécie mais isolada nas amostras coletadas para os grupos de crianças não expostas ao HIV, expostas ao HIV e portadoras da AIDS foi a Candida albicans (48,8%; 25,64% e 58,13% respectivamente). Foram também isoladas espécies de Candida não-albicans em todos os grupos estudados. CONCLUSÕES: Observou-se que apesar de haver uma prevalência de espécies de Candida albicans isoladas, as espécies não-albicans perfizeram um percentual significativo dos isolados dessa espécie. .

Effectiveness of antimicrobial photodynamic therapy using a 660 nm laser and methyline blue dye for inactivating Staphylococcus aureus biofilms in compact and cancellous bones: An in vitro study.

BACKGROUND: New therapeutic modalities such as antimicrobial photodynamic therapy (APDT) has been investigated in order to be a valid alternative to the treatment of infections caused by different microorganisms. This work evaluated the in vitro effectiveness of Antimicrobial Photodynamic Therapy (APDT) using 660 nm laser combined with methylene blue dye to inactivate Staphylococcus aureus (ATCC 25923) biofilms in compact and cancellous bones specimens. METHODS: Eighty specimens of compact bone and 80 specimens of cancellous bone were contaminated with a standard suspension of S. aureus and incubated for 14 days at 37°C to induce the formation of biofilms. The specimens were then divided into groups (n = 10) according to the established treatment: PS-L- (control--no treatment), PS+L- (only AM for 5 min in the dark), PS-L+90 (only laser irradiation for 90 s), PS-L+180 (only laser irradiation for 180 s), PS-L+300 (only laser irradiation for 300 s), APDT90 (APDT for 90 s), APDT180 (APDT for 180 s), and APDT300 (APDT for 300 s). The findings were statistically analyzed by ANOVA 5%. RESULTS: All of the experimental treatments showed a significant reduction (log 10 CFU/mL) of S. aureus biofilms in compact and cancellous bones specimens compared with the control group, and the APDT group was the most effective. Compact specimens treated with APDT showed the greatest reduction in biofilms compared with cancellous specimens, regardless of length of treatment. CONCLUSION: APDT with methylene blue dye and a 660 nm laser proved to be effective in inactivating S. aureus biofilms formed in compact and cancellous bone.

In vitro effectiveness of antimicrobial photodynamic therapy (APDT) using a 660 nm laser and malachite green dye in Staphylococcus aureus biofilms arranged on compact and cancellous bone specimens.

The aim of this study was to evaluate the in vitro effectiveness of antimicrobial photodynamic therapy (APDT) using a 660 nm visible laser combined with malachite green (MG) dye in the inactivation of Staphylococcus aureus (ATCC 25923) biofilms formed within compact and cancellous bone specimens. Specimens of 80 compact bones and 80 cancellous bones were contaminated with a standard suspension of S. aureus and incubated for 14 days at 37 °C to allow for the formation of biofilms. The specimens were divided into the following groups (n = 10) according to the treatment conditions: PS-L - (control - no treatment), PS+L - (only MG for 5 min), PS-L + 90 (only laser irradiation for 90 s), PS-L + 180 (only laser irradiation for 180 s), PS-L + 300 (only laser irradiation for 300 s), APDT90 (APDT for 90 s), APDT180 (APDT for 180 s), and APDT300 (APDT for 300 s). The findings were statistically analyzed using an ANOVA 5%. All of the experimental groups were significantly different from the control group for both the compact and cancellous bone specimens. The compact bone specimens that received APDT treatment (for either 90, 180, or 300 s) showed reductions in the log10 CFU/ml of S. aureus by a magnitude of 4 log10. Cancellous bone specimens treated with 300 s of APDT showed the highest efficacy, and these specimens had a reduction in S. aureus CFU/ml by a factor of 3 log10. APDT treatment using these proposed parameters in combination with MG was effective at inactivating S. aureus biofilms in compact and cancellous bone specimens.