A series of structurally related BODIPY dyes were synthesised and characterised. Their photophysical properties were studied in order to determine whether they would be suitable candidates for use as photosensitisers in the photodynamic therapy (PDT) treatment of cancer. The synthesis of two highly fluorescent BODIPY cores was achieved via the acid-catalysed condensation of a pyrrole and a functionalised aldehyde. In order to promote intersystem crossing, and hence improve the singlet oxygen generation of these dyes, bromine atoms were added at the 2,6-positions of the BODIPY core. These dibrominated analogues showed good singlet oxygen quantum yields, and excellent photostability in ethanol. In order to red-shift the main spectral bands of the BODIPY dyes towards the therapeutic window, vinyl/ styryl groups were introduced at the 3-, 5-, and 7-positions via a modified Knoevengal condensation reaction. The addition of vinyl/ styryl groups to the BODIPY core caused an increase in fluorescence quantum yield as well as a decrease in singlet oxygen quantum yield with respect to the dibrominated analogues. However, two of the red-shifted BODIPY dyes still showed moderate singlet oxygen quantum yields. The use of BODIPY dyes in nonlinear optics (NLO) was explored. The nonlinear optical characterisations and optical limiting properties of a series of 3,5-dithienylenevinylene BODIPY dyes were studied, both in dimethylformamide (DMF) solution and when embedded in poly(bisphenol A carbonate) (PBC) as thin films. The 3,5-dithienylenevinylene BODIPY dyes showed typical nonlinear absorption behaviour, with reverse saturable absorption (RSA) profiles, indicating that they have potential as optical limiters. The second-order hyperpolarizability (Y), and third-order nonlinear susceptibility (/m[/(3)]) values are also reported for these dyes. The optical limiting values of one of the BODIPY dyes in solution, and two of the BODIPY-embedded PBC films, were below the maximum threshold of 0.95 J-cm-2. The effect of addition of substituents on the electronic structure of the BODIPY dyes was investigated using TD-DFT calculations. The calculated trends closely followed those determined experimentally.

M.Sc. / The ideal cancer treatment modality should not only cause tumour regression and eradication but also induce a systemic antitumour response, which is essential for the control of metastatic tumours and long-term tumour resistance. Photodynamic Therapy (PDT) is a current approach in the treatment of various cancers. It involves the administration of a tumour-localizing photoreactive compound, which is activated at a specific wavelength of light. This therapy results in a sequence of photochemical and photobiological processes that cause irreversible photodamage to tumour tissues. Eradication is achieved by anti-tumour effects induced in the parenchyma and tumour vascular network. PDT can lead to a rapid cell death response in malignant cells, which has provided insight into the mechanisms behind photokilling. Oesophageal cancer is the seventh leading cause of cancer death worldwide, and in South Africa remains a problem of epidemic proportions affecting predominantly black males. The appearance of a number of new photosensitizers being developed will not only extend the number of choices for treating specific cancers, but also aid in the effective destruction of various tumour tissues. PDT has been an experimental clinical modality for the past two xii decades and has been shown to be successful for the treatment of advanced oesophageal cancer where other options have failed. The full potential of PDT as a treatment modality has not been clearly evaluated, which is one of the objectives of this study. Overall, PDT has the potential of being a promising therapeutic option in the effective treatment of oesophageal cancer, and through this study and the elucidation of the mechanisms of PDT action, it will provide a better future for those suffering from oesophageal cancer. A new photosensitizer known as Zinc Sulphophthalo-cyanine (ZnPcSmix) was studied on an oesophageal SNO cancer cell line in order to determine treatment-induced cell viability, cytotoxicity and the pathway followed to cell death. The major observations of this study revealed that PDT using ZnPcSmix resulted in a decrease in cell viability and proliferation, resulting in a cytotoxic response experienced by the cell. The outcome of this study revealed that the SNO cells experience a necrotic mode of cell death after using ZnPcSmix to induce photodamage. This was examined by light microscopy and confirmed by the lack of DNA fragmentation and decreased caspase-3 and caspase-7 expression levels. Hsp70 levels decreased resulting in lowered cytokine TNF-α release from necrotic cells. Hoechst nuclear staining revealed a disorganized nuclear pattern characteristic of necrotic release of cellular contents. The major findings of this study revealed the efficacy of ZnPcSmix as a new photosensitizing drug used during PDT to treat oesophageal cancer resulting in a decrease in cell viability and proliferation. Necrosis was the primary mechanism by which cells pursued death, which was dependent on the photosensitizer dose, cell type and irradiation fluence. ZnPcSmix–induced photodamage seen during PDT offers a new treatment option for patients suffering from oesophageal cancer and shows great promise in effectively treating early-stage oesophageal cancer.

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Orientador: Daniela Leal Zandim-Barcelos / Resumo: A resistência bacteriana é uma ameaça real alertada pela OMS. A terapia fotodinâmica antimicrobiana (TFDA) pode ser uma das soluções para superar este desafio, uma vez que já demonstra ação antimicrobiana frente a inúmeros patógenos. A clorina-e6 (Ce6) provou ser um fotossensibilizador (FS) com potente efeito quando irradiada pela luz vermelha, contra diferentes biofilmes. No entanto, o principal pico de absorção deste FS está no espectro visível de luz azul, ainda insuficientemente investigado. Este estudo teve como objetivo avaliar o efeito da TFDA com utilização da Ce6 irradiada a 450 e 660 nm contra biofilmes relacionados à doença periodontal. Biofilmes monoespécie de Streptococcus oralis, Fusobacterium nucleatum, Porphyromonas gingivalis e Aggregatibacter actinomycetemcomitans foram desenvolvidos em condições adequadas por cinco dias. A TFDA foi realizada em diferentes concentrações de fotossensibilizador (100 e 200 µM) e comprimentos de onda de luz (450 e 660 nm), e comparada ao controle negativo (DMSO a 1%) e positivo (clorexidina a 0,2%) por análise de unidades formadoras de colônias (UFC) e microscopia confocal. O uso de luz e FS também foram testados individualmente. A maior redução bacteriana foi observada no grupo em que a TFDA foi realizada com utilização da Ce6 a 200 µM e aplicação de luz azul para todas as cepas (redução de 4,01 log10 para A. actinomycetemcomitans e redução total para P. gingivalis e S. oralis), exceto para F. nucleatum, onde o melhor resultado... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

Chan, Man Hung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 111-126). / Abstract also in Chinese. / Examination Committee List --- p.ii / Declaration --- p.iii / Acknowledgements --- p.iv / 摘要（Abstract in Chinese) --- p.vi / Abstract --- p.viii / List of Abbreviations --- p.x / List of Figures and Tables --- p.xii / Table of Content --- p.xiv / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background of photodynamic therapy (PDT) --- p.2 / Chapter 1.1.1 --- History of PDT --- p.2 / Chapter 1.1.2 --- Photochemistry --- p.3 / Chapter 1.1.3 --- Principal stages of PDT --- p.5 / Chapter 1.1.4 --- Light sources of PDT --- p.6 / Chapter 1.2 --- Anti-tumor effect of PDT --- p.8 / Chapter 1.2.1 --- Mode of cell death --- p.8 / Chapter 1.2.2 --- PDT-induced anti-tumor immunity --- p.9 / Chapter 1.3 --- Clinical applications of PDT --- p.11 / Chapter 1.3.1 --- Photofrin® --- p.11 / Chapter 1.3.2 --- Clinical applications of PDT --- p.13 / Chapter 1.3.3 --- Challenges of PDT for clinical applications --- p.15 / Chapter 1.4 --- The development of new photosensitizers --- p.16 / Chapter 1.4.1 --- Targeted PDT --- p.16 / Chapter 1.4.2 --- Phthalocyanine --- p.18 / Chapter 1.5 --- Objective of my study --- p.21 / Chapter Chapter 2 --- Materials and Methods --- p.23 / Chapter 2.1 --- Synthesis of glucosylated silicon(IV) phthalocyanine (SiPcGlu) --- p.24 / Chapter 2.2 --- In vitro studies --- p.24 / Chapter 2.2.1 --- Cell line and culture conditions --- p.24 / Chapter 2.2.2 --- Photodynamic treatment --- p.25 / Chapter 2.2.3 --- Cell viability assay --- p.27 / Chapter 2.2.4 --- Light dose effect on the photocytotoxicity of SiPcGlu-PDT --- p.27 / Chapter 2.2.5 --- Determination of reactive oxygen species (ROS) production by SiPcGlu-PDT --- p.29 / Chapter 2.2.6 --- Effect of antioxidants on the photocytotoxicity of SiPcGlu-PDT --- p.29 / Chapter 2.2.7 --- Determination of ROS production after SiPcGlu-PDT --- p.30 / Chapter 2.2.8 --- Glucose competitive assay --- p.30 / Chapter 2.2.9 --- Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay --- p.30 / Chapter 2.2.10 --- DNA fragmentation analysis by gel electrophoresis --- p.31 / Chapter 2.2.11 --- Annexin-V & propidium iodide staining assay --- p.32 / Chapter 2.2.12 --- Subcellular localization studies --- p.33 / Chapter 2.2.13 --- Detection of mitochondrial superoxide production --- p.34 / Chapter 2.2.14 --- Assessment of mitochondrial membrane potential --- p.34 / Chapter 2.2.15 --- Caspase-3 activity assay --- p.35 / Chapter 2.2.16 --- "Western blot analyses for cytochrome c, caspase-3, PARP and glucose-regulated protein 78 (GRP78)" --- p.36 / Chapter 2.2.17 --- Ca2+ release from endoplasmic reticulum (ER) --- p.37 / Chapter 2.3 --- In vivo studies --- p.37 / Chapter 2.3.1 --- HT29 tumor-bearing nude mice model --- p.37 / Chapter 2.3.2 --- In vivo photodynamic treatment --- p.39 / Chapter 2.3.3 --- Biodistribution of SiPcGlu --- p.39 / Chapter 2.3.4 --- Assay for plasma enzyme activities --- p.40 / Chapter 2.4 --- Statistical analysis --- p.41 / Chapter Chapter 3 --- Results --- p.42 / Chapter 3.1 --- In vitro studies --- p.43 / Chapter 3.1.1 --- SiPcGlu-PDT induced cytotoxicity on HT29 cells --- p.43 / Chapter 3.1.2 --- Light dose effect on cytotoxicity by SiPcGlu-PDT --- p.46 / Chapter 3.1.3 --- SiPcGlu-PDT induced ROS production --- p.48 / Chapter 3.1.4 --- SiPcGlu-PDT induced cell death through Type I and II photoreactions --- p.48 / Chapter 3.1.5 --- ROS production after SiPcGlu-PDT --- p.51 / Chapter 3.1.6 --- Glucose competitive Assay --- p.55 / Chapter 3.1.7 --- SiPcGlu-PDT induced apoptosis in HT29 cells --- p.57 / Chapter 3.1.8 --- Subcellular localization of SiPcGlu --- p.61 / Chapter 3.1.9 --- SiPcGlu-PDT induced mitochondrial changes --- p.66 / Chapter 3.1.10 --- SiPcGlu-PDT induced caspase activation --- p.68 / Chapter 3.1.11 --- SiPcGlu-PDT increased expression of ER chaperone GRP78 --- p.72 / Chapter 3.1.12 --- SiPcGlu-PDT induced release of Ca2+ from ER --- p.72 / Chapter 3.2 --- In vivo studies --- p.75 / Chapter 3.2.1 --- In vivo photodynamic activities --- p.75 / Chapter 3.2.2 --- Tissue distribution of SiPcGlu --- p.77 / Chapter 3.2.3 --- Analysis of intrinsic toxicity --- p.77 / Chapter Chapter 4 --- Discussion --- p.80 / Chapter 4.1 --- Physical Properties of SiPcGlu --- p.81 / Chapter 4.2 --- In vitro studies --- p.82 / Chapter 4.2.1 --- SiPcGlu-PDT exhibits a high potency in killing HT29 cells --- p.82 / Chapter 4.2.2 --- ROS production is responsible for the cytotoxic effect of SiPcGlu-PDT --- p.83 / Chapter 4.2.3 --- SiPcGlu-PDT induced apoptosis in HT29 cells --- p.85 / Chapter 4.2.4 --- SiPcGlu is localized in various membranous organelles --- p.87 / Chapter 4.2.5 --- SiPcGlu-PDT induced mitochondria-mediated apoptosis --- p.89 / Chapter 4.2.6 --- SiPcGlu-PDT induced ER stress --- p.93 / Chapter 4.3 --- In vivo studies --- p.96 / Chapter 4.3.1 --- SiPcGlu failed to target to tumor tissues --- p.96 / Chapter 4.3.2 --- SiPcGlu-PDT induced retardation in tumor growth --- p.99 / Chapter 4.3.3 --- SiPcGlu is a safe photosensitizer for PDT --- p.101 / Chapter Chapter 5 --- Conclusion and Future Perspectives --- p.103 / Chapter 5.1 --- Conclusion --- p.104 / Chapter 5.2 --- Future Perspectives --- p.106 / Chapter 5.2.1 --- In vitro studies --- p.106 / Chapter 5.2.1.1 --- Lysosomal pathway to cell death --- p.106 / Chapter 5.2.2 --- In vivo studies --- p.107 / Chapter 5.2.2.1 --- Pharmacokinetic studies --- p.107 / Chapter 5.2.2.2 --- Eradication of HT29 tumor by repeated dose of SiPcGlu --- p.108 / Chapter 5.2.2.3 --- SiPcGlu-PDT-induced anti-tumor immunity --- p.108 / Chapter 5.2.2.4 --- Enhancement of tumor selectivity by conjugating with biomolecules --- p.109 / References --- p.110

O objetivo do estudo foi avaliar o efeito de repetidas aplicações da Terapia Fotodinâmica antimicrobiana (TFDa) adjuvante ao tratamento periodontal não cirúrgico em pacientes fumantes. Foram selecionados 20 indivíduos fumantes com diagnóstico clínico de periodontite crônica. O estudo foi do tipo boca dividida, sendo um lado utilizado a TFDa associada à raspagem e alisamento radicular (RAR) e no outro apenas RAR. Foi utilizado laser com 660nm de comprimento de onda associada ao fotosensibilizador fenotiazida e as aplicações foram realizadas em 4 episódios (dias 0, 2, 7 e 14). Todos os pacientes foram acompanhados por 90 dias. As avaliações clínicas de índice de placa (IP), profundidade de sondagem (PS), nível clínico de inserção (NCI), sangramento à sondagem (SS) e sangramento marginal (SM) foram realizadas no baseline, 0, 30 e 90 dias após a execução do tratamento. Foi realizada análise microbiológica para contagem de 40 espécies bacterianas da amostra subgengival da placa bacteriana (Checkerboard DNA-DNA hybridization). Níveis das citocinas do fluido crevicular gengival foram avaliados (Interleucina-1β, Interleucina-10 e Fator de Necrose Tumoral Alpha). Os dados obtidos foram analisados estatisticamente. Em geral não foram observadas diferenças estatisticamente significantes entre os grupos (p &lt0,05) nos parâmetros clínicos, microbiológicos e imunológicos 90 dias após o tratamento. O tratamento periodontal com RAR + TFDa em múltiplos episódios não promoveu benefícios adicionais à RAR no tratamento não cirúrgico da periodontite crônica em fumantes sem o uso de antibióticos sistêmicos / The aim of this study was to investigate the additional influence of multiple applications of antimicrobial Photodynamic Therapy (aPDT) in smokers without use of systemic antibiotics. Twenty smokers with chronic periodontitis were treated in a split-mouth design study with aPDT adjunct to Scaling and Root Planing (SRP) or SRP only. aPDT was performed by using a laser light source with 660 nm wavelength associated with a photosensitizer. The applications were performed in four episodes (at days 0, 2, 7 and 14). All patients were monitored for 90 days. Plaque index, probing depth, clinical attachment level, bleeding on probing and marginal bleeding were performed at baseline, 0, 30 and 90 days after the SRP. Counts of 40 subgingival species in plaque samples were monitored (Checkerboard DNA-DNA hybridization). Gingival crevicular fluid and subgingival plaque samples were collected (Interleukin 1β, Interleukin 10 e Tumor necrosis factor. Data obtained were statistically analyzed. aPDT as an adjunct to SRP did not demonstrate statistically significant advantages on clinical parameters when compared with SRP alone. In general no statistic significant differences between groups were observed (p &lt0.05). Levels of anti-inflammatory cytokines and bacterial species were comparable in both groups at day 90 after treatment. Periodontal treatment with SRP + aPDT in multiples episodes was not able to improve results in the non-surgical treatment of chronic periodontitis in smokers when compared SRP alone, without the use of systemic antibiotics

At the end of this thesis, the 1H and 13C {1H} NMR spectra of all the new compounds are listed in the Appendix. / Chapter 1 presents an overview of BODIPYs, including their general synthesis, properties, reactivities, and applications. The use of these compounds as photosensitizers for photodynamic therapy and fluorescent sensors for metal ions is highlighted. / Chapter 2 reports the synthesis, spectroscopic characterization, photophysical propreties, and in vitro photodynamic activities of a series of symmetrical distyryl BODIPYs substituted with one to five hydrophilic oligoethylene glycol monomethyl ether chain(s). In general, these compounds are essentially non-aggregated in DMF, resulting in a strong fluorescence emission and relatively high efficiency in generating singlet oxygen. Being formulated with 0.05% Tween 80, these compounds act as efficient photosensitizers. The compound which contains five triethylene glycol monomethyl ether chains exhibits the highest photocytotoxicity with an IC50 value as low as 7 nM toward HT29 human colorectal carcinoma cells. The high photodynamic activity of this compound can be attributed to its high efficiency in generating singlet oxygen, low aggregation tendency, and high cellular uptake. In addition, this compound also has a strong and selective affinity to the endoplasmic reticulum of the cells, causing cell death mainly through apoptosis. / Chapter 3 reports a related study on a series of unsymmetrical distyryl BODIPYs. These compounds possess three triethylene glycol monomethyl ether chains and another substituent at the other styryl group. The effects of this substituent on the photophysical properties, aggregation behavior, cellular uptake, and subcellular localization have been explored. Furthermore, their in vitro photodynamic activities have also been evaluated and compared with those of symmetrical analogues reported in Chapter 2. / Chapter 4 describes a novel ratiometric near-infrared fluorescent dye based on distyryl BODIPY with a 4-dimethylaminophenylethynyl group at the 2- and 6-positions. This compound exhibits a remarkable blue-shift in its absorption and fluorescence emission positions upon protonation with trifluoroacetic acid in organic solvents or HC1 in water in the presence of 0.05% Tween 80. These changes can be made reversible upon addition of a base. / Chapter 5 describes two monostyryl BODIPYs which contain two or four water-soluble amide chains as the metal chelators. The photophysical properties of these compounds and their spectral response to various metal ions have been investigated. The results show that the compound with two amide chains can detect Zn2+ ion in MeCN. They bind in a 1:1 stoichiometry with a binding constant of 2.2 x 104 M-1 . The fluorescence emission increases remarkably in intensity and shifts substantially to the blue from 620 to 572 nm due to the inhibition of the intramolecular charge transfer. The compound which contains four amide chains can detect Cd2+ ion with a high selectivity in phosphate buffered saline. / Chapter 6 reports the synthesis and spectral properties of a silicon(IV) phthalocyanine with two axial bis(2-picolyl)amine moieties which act as the binding sites for metal ions. The effects of various metal ions on its absorption and fluorescence spectra have been examined. The results indicate that this compound shows a relatively high sensitivity to Zn 2+ ion. Moreover, the proposed binding mode and the sensing mechanism are also discussed. / This thesis describes the synthesis and characterization of several series of functional boron dipyrromethenes (BODIPYs) and a silicon(IV) phthalocyanine. Their applications as efficient photosensitizers in photodynamic therapy and selective fluorescent sensors for metal ions are also reported herein. / He, Hui. / Adviser: Dennis Kee Pui Ng. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A periodontite agressiva é um processo inflamatório de origem bacteriana mediado pelo sistema imunológico do hospedeiro e é provavelmente a forma mais grave de doença periodontal, apresentando destruição das estruturas tanto de proteção quanto de suporte dentário, num período relativamente rápido, normalmente levando a perda prematura dos elementos dentários e, em alguns casos, terapia antimicrobiana adjunta é necessária em adição à terapia mecânica. O objetivo do presente ensaio clínico randomizado controlado foi avaliar o efeito clínico da terapia fotodinâmica como adjunto ao tratamento periodontal não cirúrgico no tratamento da periodontite agressiva Os seguintes parâmetros clínicos foram avaliados: índice de placa visível, sangramento à sondagem, profundidade de bolsa à sondagem, nível de inserção clínica relativo, envolvimento de furca e mobilidade. Foram selecionados dez pacientes com periodontite agressiva, os quais foram examinados no dia zero e após três meses.O desenho do estudo consistiu em um modelo de boca dividida, onde um hemiarco foi tratado com raspagem e alisamento radicular e terapia fotodinâmica (laser diodo) e o outro apenas com raspagem e alisamento radicular. Três meses após o término do tratamento, os grupos terapêuticos apresentaram resultados semelhantes para todos os parâmetros clínicos avaliados: ambas as terapias tiveram sucesso, como redução de profundidade de bolsa, ganho de nível de inserção clínica relativo, redução de índice de placa visível, redução de sangramento à sondagem, diminuição de envolvimento de furca e diminuição de mobilidade, porém sem diferenças estatisticamente significantes entre elas. Dentro das limitações do presente estudo, os resultados sugerem que a terapia fotodinâmica adjuntamente ao tratamento periodontal não cirúrgico mecânico foi tão eficaz quanto o tratamento periodontal não cirúrgico mecânico sozinho. / Aggressive periodontitis is an inflammatory process of bacterial origin mediated by host immune response and is probably the most serious form of periodontal disease, with destruction of the structures of protection and support, with fast course, often leading to premature loss of the teeth and, in some cases, adjunct antimicrobial therapy is need in addition to mechanical therapy. The aim of this randomized controlled trial was to investigate the clinical effect of photodynamic therapy as an adjunct to nonsurgical periodontal treatment in patients with aggressive periodontitis. The following clinical parameters were evaluated: visible plaque index, bleeding on probing, probing pocket depth, relative attachment level, furcation involvement and mobility. We selected ten patients with aggressive periodontitis, which were examined in the baseline to three months. The study design consisted of a split mouth model, where a quadrant was treated with scaling and root planing and photodynamic therapy (diode laser) and the other only with scaling and root planing. Three months after the end of the treatment, the treatment groups showed similar results for all clinical parameters evaluated: both therapies have been successful and showed reduction of pocket depth, gain of relative attachment level, reduction of visible plaque index, reduction of bleeding on probing, decreased furcation involvement and decreased mobility, but without statistically significant differences between them. Within the limitations of the present study the results suggest that photodynamic therapy adjunct to non-surgical periodontal mechanic treatment was as effective as the non-surgical periodontal mechanic treatment alone.

Made available in DSpace on 2017-03-14T14:10:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-03-05 / O objetivo deste trabalho, dividido em dois estudos, foi avaliar: (1) a influência da terapia fotodinâmica antimicrobiana na alteração de cor da dentina utilizando azul de metileno e curcumina como fotossensibilizadores nas concentrações de 20, 40 e 60 µM e nos tempos de pré-irradiação de 2 e 5 minutos, irradiados com fonte de luz LED; e (2) a influência do mesmo tratamento antimicrobiano com os mesmos fotossensibilizadores, concentrações e tempos de pré-irradiação utilizados no estudo anterior, porém sobre alteração de cor em uma resina composta microhíbrida. No primeiro estudo foram confeccionados 130 espécimes a partir de dentes humanos extraídos, os quais foram seccionados em máquina de cortes Isomet. Após a imersão nos fotossensibilizadores, avaliou-se as alterações de cor através de um espectrofotômetro de colorimetria em quatro momentos: antes do início da imersão nas soluções dos fotossensibilizadores (L0), após imersão nos fotossensibilizadores (L1), após irradiação (L2), após 10 dias (L3), após 30 dias (L4) e após 60 dias (L5). Observou-se uma variação alta das médias de ∆E nos grupos com azul de metileno independentemente da concentração e do tempo de exposição, diminuindo a partir da leitura de 10 dias. Com os grupos com curcumina, houve uma variação inicial sem diferença significativa do controle, mantendo-se próxima a ele nas leituras seguintes. Ambos fotossensibilizadores apresentaram alterações significantes clinicamente em dentina segundo a classificação da ―National Bureau of Standards‖ (NBS), sendo a alteração com a curcumina menor que do azul de metileno. No segundo estudo foram confeccionados 130 espécimes de resina composta microhíbrida (Filtek Z250XT) utilizando uma matriz de aço (10x2mm). Após a confecção dos espécimes, estes foram imersos...(Resumo completo, clicar acesso eletrônico abaixo) / This study, divided in two studies, was to evaluate: (1) the influence of antimicrobial photodynamic therapy in color change dentin using methylene blue and curcumin as photosensitizers in concentrations of 20, 40 and 60 uM and pre irradiation times 2 to 5 minutes, irradiated with a LED light source; and (2) the effect of the same antimicrobial treatment with the same photosensitizers, concentrations and pre-irradiation times used in the previous study, but on color change in a microhybrid composite. In the first study were produced 130 specimens from extracted human teeth, which were cut in Isomet cuts machine. After immersion in the photosensitizers, the color changes were evaluated using a spectrophotometer colorimeter in four stages: before the immersion in solutions of photosensitizers (L0) after immersion in photosensitizers (L1) after irradiation (L2), after 10 days (L3) after 30 days (L4) and 60 days (L5). There was a high variation of ΔE averages of the methylene blue groups independently of the concentration and exposure time, decreasing from a reading of 10 days. With curcumin groups, there was no significant difference initial variation control, remaining next to it in the subsequent readings. Both photosensitizers showed clinically significant changes in dentin according to the classification of ―National Bureau of Standards‖ (NBS), with a lowest change to curcumin that of methylene blue. In the second study were made 130 specimens microhybrid composite resin (Filtek Z250XT) using a steel matrix (10x2mm). After preparation of the specimens, they were immersed in solutions of photosensitizers and subsequently evaluated with a spectrophotometer Colorimetry in the same color reading moments performed in the previous study (initial, after immersion, after light irradiation, after 10, 30 and 60 days). In methylene blue groups was no statistically significant difference... (Complete abstract access below)

Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes bibliographical references (p. 268-291).