Antimicrobial Effects of Photodynamic Therapy on Patients With Necrotic Pulps and Periapical Lesion

Abstract

This study analyzed the antimicrobial effect of photodynamic therapy (PDT) in association with endodontic treatment. Twenty patients were selected. Microbiological samples were taken after accessing the canal, endodontic therapy, and PDT. At the end of the first session, the root canal was filled with Ca(OH)2, and after 1 week, a second session of the therapies was performed. Endodontic therapy gave a mean reduction of 1.08 log. The combination with PDT significantly enhanced the reduction (1.83 log, p ! 0.00002). The second endodontic session gave a similar diminution to the first (1.14 log), and the second PDT was significantly more effective than the first (p ! 0.002). The second total reduction was significantly higher than the second endodontic therapy (p ! 0.0000005). The total first " second reduction (3.19 log) was significantly different from the first combination (p ! 0.00006). Results suggest that the use of PDT added to endodontic treatment leads to an enhanced decrease of bacterial load and may be an appropriate approach for the treatment of oral infections. (J Endod 2007;xx:xxx)


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Antimicrobial Photodynamic Therapy Combined With Conventional Endodontic Treatment to Eliminate Root Canal Biofilm Infection

Background and Objective: To compare the effectiveness of antimicrobial photodynamic therapy (PDT), standard
endodontic treatment and the combined treatment to eliminate bacterial biofilms present in infected root canals. Study Design/Materials and Methods: Ten singlerooted freshly extracted human teeth were inoculated with stable bioluminescent Gram-negative bacteria, Proteus mirabilis and Pseudomonas aeruginosa to form 3-day biofilms in prepared root canals. Bioluminescence imaging was used to serially quantify bacterial burdens. PDT employed a conjugate between polyethylenimine and chlorin(e6) as the photosensitizer (PS) and 660-nm diode laser light delivered into the root canal via a 200-m fiber, and this was compared and combined with standard endodontic treatment using mechanical debridement and antiseptic irrigation.

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Aplicação da Terapia Fotodinâmica e Laserterapia em Implantodontia

INTRODUÇÃO
As lesões da periimplantite são caracterizadas por inflamação da gengiva, migração apical do epitélio juncional e exposição das roscas do implante ao ambiente oral, gerando bolsas periimplantares. Se não tratada propriamente, pode levar à reabsorção óssea e conseqüente perda do implante. Ainda não há relato na literatura de um tratamento efetivo para a periimplantite.
O laser de baixa potência surge como um coadjuvante objetivando-se acelerar o processo de reparação, diminuir os sinais da inflamação e viabilizar a neoformação óssea.
A terapia fotodinâmica, por meio da associação da luz vermelha do laser com o corante azul de metileno, irá promover a redução bacteriana, sendo uma importante ferramenta, aliada a terapia convencional, no tratamento da periimplantite.

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Comparative study among three different phototherapy protocols to treat chemotherapy-induced oral mucositis in hamsters

In this study, clinical, biochemical and histological analysis were used to compare different phototherapies, including LED, low and high-power laser (HPL) for the treatment of chemotherapy (CT)-induced oral mucositis (OM). One-hundred-fifty hamsters were divided into five groups: C: control; CH: CT/OM induction; L: CT/OM induction and treatment with LED (635 nm, 1.2 J), HL: CT/ OM induction and treatment with HPL (808 nm, 10 J), LL: CT/OM induction and treatment with low-level laser therapy (LLLT) (660 nm, 1.2 J). OM was induced by scratches performed on check pouch mucosa after two injections of 5-Fluorouracil. The experiment lasted 10 days and OM was analyzed by specific clinical scales on days 5, 7 and 10. The animals were euthanized and the cheek pouch mucosa removed for biochemical (TNF-α concentration) and histological (light microscopy) analysis. After statistical analysis, the authors’ results showed LED and LLLT therapies were efficient treatments for OM, decreasing TNF-α concentration on day 7 (p < 0.05) and completely healing the mucosa on day 10. HPL showed no interference in final healing of OM. According to the methodology used and the results obtained in the present study, LLLT and LED therapies were the best choices to decrease the severity of OM, accelerating tissue repair and decreasing the inflammatory process.

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Uso da LEDTERAPIA na Mucosite Oral: Avanços na Prevenção e Tratamento.

De acordo com o Instituto Nacional do Câncer (INCA), estima-se para o Brasil no biênio 2018-2019, a ocorrência de 600 mil novos casos de câncer. Os principais tratamentos para esta condição consistem em Cirurgia, Quimioterapia e Radioterapia, que podem ser de forma combinada ou não.
O tratamento antineoplásico promove uma série de efeitos colaterais, pois não existe uma seletividade apenas pelas células neoplásicas. Esses efeitos adversos diminuem muito a qualidade de vida dos pacientes.
Neste contexto, a Mucosite Oral (MO) representa uma reação adversa nos protocolos de Radioterapia (RT) e Quimioterapia (QT) na Oncologia, representando a maior complicação nos pacientes que fazem RT em neoplasias na região da cabeça e pescoço, e em associação com a QT pode ser um sério problema dose-limitante, tendo muitas vezes que se realizar a interrupção do tratamento de base, em virtude do surgimento e agravamento de tais lesões e consequentemente sobrevida do paciente. A ruptura da integridade da mucosa resulta nesta condição, produto dos efeitos citotóxicos da terapia oncológica.

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Photodiagnosis and Photodynamic Therapy

Abstract
Background: Photobiomodulation (PBM) therapy is a rapidly growing approach to stimulate healing, reduce pain, increase athletic performance, and improve general wellness. Objective: Applying PBM therapy over the site of a tumor has been considered to be a contraindication. However, since another growing use of PBM therapy is to mitigate the side effects of cancer therapy, this short review seeks to critically examine the evidence of whether PBM therapy is beneficial or harmful in cancer patients. Materials and methods: PubMed and Google Scholar were searched. Results: Although there are a few articles suggesting that PBM therapy can be detrimental in animal models of tumors, there are also many articles that suggest the opposite and that light can directly damage the tumor, can potentiate other cancer therapies, and can stimulate the host immune system. Moreover, there are two clinical trials showing increased survival in cancer patients who received PBM therapy. Conclusions: PBM therapy may have benefits in cancer patients and should be further investigated.

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Tratamento do herpes labial pela terapia fotodinâmica​​

Descrição de Casos – MM Optics

Caso 1

Paciente do gênero feminino, 25 anos, apresentou-se no LELO-FOUSP com queixa de herpes labial na fase de vesícula no lábio superior esquerdo (A) devido a intenso estresse no dia anterior. Foi proposto tratamento por meio da terapia fotodinâmica para a fase de vesícula e laserterapia para a fase de crosta. A Figura 1 mostra os passos utilizados durante o tratamento: drenagem das vesículas com agulha estéril (B), aplicação do corante azul de metileno 0,01% m/V por 5 minutos (C) e irradiação com laser de baixa potência (Twin Flex Laser – MM Optics) pela técnica pontual em contato, modo contínuo, comprimento de onda de 660nm, 120J/cm² de densidade de energia, 40mW de potência, 2min por ponto, 4 pontos na lesão. A paciente retornou após 24h, 72h (D) e 1 semana para a laserterapia objetivando-se aceleração do processo de reparação tecidual (E): Twin Flex Laser, técnica pontual em contato, modo contínuo, comprimento de onda de 660nm, 3,8J/cm² de densidade de energia, 15mW de potência, 10s por ponto, 4 pontos na lesão. Observou-se reparação completa das lesões após 1 semana (F).

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Tratamento do herpes labial pela terapia fotodinâmica​​

Resumo
O sucesso do PDT e seu estabelecimento no hall das modalidades da terapêuticas existentes depende da coleção de experiências relatadas ao redor o mundo. Nesse sentido, é importante relatar abordagens adotadas por diferentes países e quais são seus pontos de vista sobre o futuro do PDT. Seguindo esta idéia, nós apresentar nossa experiência clínica em Terapia fotodinâmica (PDT) no Brasil, bem como os avanços experimentais chegando em paralelo com aplicação clínica. Esse relatório é uma consequência de trabalhos pioneiros em um programa de colaboração envolvendo o Instituto de Física em São Carlos, SP, Brasil, a Faculdade de Medicina a Paulo, da Universidade de São Paulo, Ribeirão Preto, SP, Brasil e o Hospital de Câncer
Amaral Carvalho, Jaú, SP, Brasil. Este programa colaborativo, iniciado em 1997, com o primeiro paciente tratado em 1999, tratou mais de 400 pacientes até o final de 2004. Cerca de 80% dos lesões foram localizadas na cabeça e pescoço ou pele, mas experiência está sendo incorporada ao esôfago, bexiga, ginecologia e recorrência cutânea do cancro da mama, entre outros. Os resultados mostraram serem compatíveis com os dados anteriormente relatados. Modificações, cujo objetivo é melhorar o benefício dos doentes e otimizar resultados, estão sendo implementadas como podemos ganhar experiência. Em paralelo com o desenvolvimento clínico, vários laboratórios começaram estudo experimental, cujo objetivo é analisar os resultados clínicos e contribuir para o esforço mundial para colocar o PDT em primeiro plano das terapias oferecidas aos pacientes. Apresentamos os resultados globais da nossos 5 anos de experiência, bem como todo o processo de implementação.

© 2005 Elsevier B.V. All rights reserved.


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Antimicrobial comparison on effectiveness of endodontic therapy and endodontic therapy combined to photo-disinfection on patients with periapical lesion. A 6-month follows up.

ABSTRACT
This study compares the antimicrobial effect of photodynamic therapy (PDT) combined to endodontic treatment with conventional endodontic treatment alone in patients with necrotic pulp and has a 6-month radiographic follow up comparing the healing of periapical lesions. Fifteen patients with periapical lesion and requiring root canal treatment were selected. Microbiological samples were taken after accessing the root canal, conventional manual endodontic therapy (group 1 n=5) and after accessing the canal, endodontic therapy and PDT (group 2 n=10). All the root canals were filled with a calcium hydroxide paste for 1 week. Radiographs were taken after obturation and following 6 months. Endodontic therapy alone presented an 87% reduction in microorganisms while the combination with PDT had a 95% reduction. Radiographic follow up showed 32% higher reduction in the lesion area in PDT group. Results suggest that the use of PDT added to conventional endodontic treatment leads to a further major reduction of microbial load. PDT is an efficient alternative to chemical antimicrobial agents. It is a non-cumulative local treatment, which may be an appropriate approach for the treatment of infections in the oral cavity.

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Antimicrobial Photodynamic Therapy Combined With Conventional Endodontic Treatment to Eliminate Root Canal Biofilm Infection

Background and Objective: To compare the effectiveness of antimicrobial photodynamic therapy (PDT), standard endodontic treatment and the combined treatment to eliminate bacterial biofilms present in infected root canals. Study Design/Materials and Methods: Ten singlerooted freshly extracted human teeth were inoculated with stable bioluminescent Gram-negative bacteria, Proteus mirabilis and Pseudomonas aeruginosa to form 3-day biofilms in prepared root canals. Bioluminescence imaging was used to serially quantify bacterial burdens. PDT employed a conjugate between polyethylenimine and chlorin(e6) as the photosensitizer (PS) and 660-nm diode laser light delivered into the root canal via a 200-m fiber, and this was compared and combined with standard endodontic treatment using mechanical debridement and antiseptic irrigation.

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Antimicrobial mechanisms behind photodynamic effect in the presence of hydrogen peroxide

This study describes the use of methylene blue (MB) plus light (photodynamic inactivation, PDI) in the presence of hydrogen peroxide (H2O2) to kill Staphylococcus aureus, Escherichia coli, and Candida albicans. When H2O2 was added to MB plus light there was an increased antimicrobial effect, which could be due to a change in the type of ROS generated or increased microbial uptake of MB. To clarify the mechanism, the production of ROS was investigated in the presence and absence of H2O2. It was observed that ROS production was almost inhibited by the presence of H2O2 when cells were not present. In addition, experiments using different sequence combinations of MB and H2O2 were performed and MB optical properties inside the cell were analyzed. Spectroscopy experiments suggested that the amount of MB was higher inside the cells when H2O2 was used before or simultaneously with PDI, and ROS formation inside C. albicans cells confirmed that ROS production is higher in the presence of H2O2. Moreover enzymatic reduction of MB by E. coli during photosensitizer uptake to the photochemically inactive leucoMB could be reversed by the oxidative effects of hydrogen peroxide, increasing ROS formation inside the microorganism. Therefore, the combination of a photosensitizer such as MB and H2O2 is an interesting approach to improve PDI efficiency.

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