In vitro evaluation of physical and chemical parameters involved in aPDT of Aggregatibacter actinomycetemcomitans.

Periodontitis is an infectious disease characterized by the destruction of supporting tissues. Antimicrobial photodynamic therapy (aPDT) has been proposed as an improved method for eliminating microorganisms. Its efficiency depends on the correct use of physical and chemical parameters. Thus, these parameters and their relations were evaluated in this study with the purpose of establishing lethal conditions for combating bacterial agents. Diode lasers and light-emitting diodes (LEDs) were characterized to evaluate the absorption profile and resonance of methylene blue (MB) and toluidine blue O (TBO). The relations between light energy density and photosensitizer absorption were determined. Two methodologies were used to evaluate the effects of aPDT against Aggregatibacter actinomycetemcomitans. LED light exhibited a broad emission spectrum with a peak light wavelength of 637 nm and 99% purity. The resonance intensity of MB was higher with diode laser irradiation, and TBO showed higher resonance intensity with LED irradiation. There was no difference in the absorption profile of photosensitizers using diode lasers or LEDs, and variations in power density did not result in an increasing or decrease in light absorption. A. actinomycetemcomitans was susceptible to photodynamic processes. Emission spectra and peak light wavelengths of light sources combined with the absorption profiles of photosensitizers were the main parameters involved in determining the efficiency of photodynamic effects. Power density did not alter the light absorption of photosensitizers. The association between adequate irradiation characteristics and photosensitizer absorption results in complete inactivation of A. actinomycetemcomitans. In addition, the bactericidal effect was not altered by an increase in energy densities.

In vitro photodynamic inactivation of Candida spp. growth and adhesion to buccal epithelial cells.

In this study, photodynamic inactivation (PDI) was used to inhibit in vitro growth and adhesion of different Candida isolates to buccal epithelial cells (BEC). Experimental conditions were optimized and 25muM toluidine blue O (TBO) and 15min of irradiation time by light emitting diode (LED) (energy density of 180J/cm(2)) were selected due to higher reductions in cellular viability obtained after treatment. Reduction media of Log(10) 3.41 in viable cellular growth and media of 55% in the inhibition of adhesion to buccal epithelial cells were obtained. Two fluconazole resistant isolates were susceptible to PDI (Log(10) 3.54 in IB05 and Log(10) 1.95 in CG09) and a second session of this treatment for CG09 isolate inhibited cellular viability in 100%, without producing heat. The results permit to conclude that photodynamic inactivation under these experimental conditions would be a possible alternative approach to inhibit Candida spp. cellular growth and adhesion to buccal epithelial cells.

Use of Surgical Laser for Excision of a Neurofibroma Associated With Neurofibromatosis Type-1.

Introduction: Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder that affects approximately 1/3500 individuals. Various bone manifestations and peripheral nerves neoplastic lesions associated with NF1 are seen in the jaws. Several oral manifestations may occur in this disorder; therefore the dentist's knowledge and multidisciplinary management of these patients are extremely important. Case Presentation: In the present article, we present the use of a high-power surgical laser to excise a neurofibroma in a patient with several intraoral manifestations associated with NF1. Conclusion: The use of diode laser (808 nm) for excision biopsy of tongue nodules showed no thermal damage to the tissue, allowing an adequate histopathological analysis of the neurofibroma.

Clinical study of the gingiva healing after gingivectomy and low-level laser therapy.

OBJECTIVE: The purpose of this study was to investigate gingival healing after gingivectomy and adjunctive use of low-level laser therapy (LLLT). BACKGROUND DATA: LLLT has been used in animal experiments to examine the influence of laser radiation on the wound healing process since the 1960s. However, clinical trials in dentistry are scarce, and most of them refer to treatment after extraction of the third molars, with only a few reports in the area of periodontics. METHODS: Twenty patients with periodontal disease were selected, and treatment was planned for gingivectomy to bilateral maxillary and mandibular premolar teeth. After surgery, one side was submitted to LLLT using a 685-nm wavelength, output power of 50 mW, and energy density of 4 J/cm(2). The other side was used as the control and did not receive laser irradiation. Healing was evaluated, clinically and biometrically, immediately post-surgery and at days 3, 7, 14, 21, 28, and 35. Results were submitted to statistical analysis. RESULTS: Biometrical evaluation indicated a significant improvement in healing for the laser group at 21 and 28 days. Clinical evaluation showed better repair for the laser group, mainly after the third day. CONCLUSION: LLLT was an effective adjunctive treatment that appeared to promote healing following gingivectomy.

Monitoring the effectiveness of photodynamic therapy with periodic renewal of the photosensitizer on intracanal Enterococcus faecalis biofilms.

BACKGROUND AND OBJECTIVE: Photodynamic therapy (PDT) can eliminate microorganisms in a root canal. However, the parameters for disinfection remain undefined. This study assessed the effectiveness of a PDT protocol against intracanal Enterococcus faecalis biofilms. MATERIALS AND METHODS: Root canals were contaminated with E. faecalis for 21 days. The instrumentation was associated to irrigation with 0.85% saline or an alternate irrigation (AI) with 5.25% NaOCl and 17% EDTA. Complementary treatments included saline/PDT and AI/PDT. Four PDT cycles were performed using a diode laser (660nm, 40mW) delivered through a tapered optical fiber. In each cycle, the root canal was filled with 1.56µM/mL methylene blue and irradiated for 150s. Microbiological samples were collected before (S1) and after (S2) instrumentation; after PDT (S3); and daily over the course of 14 days (S4-S17). Colony-forming units (CFUs) were counted, positive cultures verified, and data subjected to parametric and proportion's tests. RESULTS: The highest bacterial load reduction was observed in S2. In regard to S3, Saline/PDT reduced 1.3 log(10) CFU counts (p=0.000 for S2) and no CFUs were recovered after AI/PDT treatment. All canals were CFU-free on the 14th day for saline/PDT, AI and AI/PDT. Positive cultures were observed in 60% of saline-irrigated canals on the 14th day, whereas the saline/PDT, AI and AI/PDT treatments resulted in germ-free canals after 10, 5 and 2 days, respectively. CONCLUSION: Our findings suggest immediate and delayed antibacterial effects using the PDT protocol tested.

Phototoxic action of light emitting diode in the in vitro viability of Trichophyton rubrum.

BACKGROUND: Trichophyton rubrum is the most common agent of superficial mycosis of the skin and nails causing long lasting infections and high recurrence rates. Current treatment drawbacks involve topical medications not being able to reach the nail bed at therapeutic concentrations, systemic antifungal drugs failing to eradicate the fungus before the nails are renewed, severe side effects and selection of resistant fungal isolates. Photodynamic therapy (PDT) has been a promising alternative to conventional treatments. OBJECTIVES: This study evaluated the in vitro effectiveness of toluidine blue O (TBO) irradiated by Light emitting diode (LED) in the reduction of T. rubrum viability. METHODS: The fungal inoculums' was prepared and exposed to different TBO concentrations and energy densities of Light emitting diode for evaluate the T. rubrum sensibility to PDT and production effect fungicidal after photodynamic treatment. In addition, the profiles of the area and volume of the irradiated fungal suspensions were also investigated. RESULTS: A small reduction, in vitro, of fungal cells was observed after exposition to 100 µM toluidine blue O irradiated by 18 J/cm² Light emitting diode. Fungicidal effect occurred after 25 µM toluidine blue O irradiation by Light emitting diode with energy density of 72 J/cm². The analysis showed that the area and volume irradiated by the Light emitting diode were 52.2 mm² and 413.70 mm³, respectively. CONCLUSION: The results allowed to conclude that Photodynamic therapy using Light emitting diode under these experimental conditions is a possible alternative approach to inhibit in vitro T. rubrum and may be a promising new treatment for dermatophytosis caused by this fungus.

Evaluation of polymeric PLGA nanoparticles conjugated to curcumin for use in aPDT

ABSTRACT Antimicrobial photodynamic therapy (aPDT) involves the association of a photosensitizing agent with a light source with the goal of causing apoptosis or microbial lysing. The use of compounds with natural active principles is gaining prominence throughout the world. Several studies from groups that are linked to the development of innovations in the pharmaceutical market have used natural dyes, such as curcumin, the efficacy of which has been demonstrated in aPDT trials. Difficulties related to physicochemical stability, solubility and cell penetration are some of the challenges associated with this field. The present work aimed to prepare, investigate the characteristics and improve the photodynamic activity of PLGA-based nanoparticles loaded with curcumin for use in aPDT therapy. Using the simple technique of emulsion during the evaporation of a solvent, the particles were built, characterized and tested against microorganisms with importance for medicine and dentistry. The results revealed that the particles were able to protect the curcumin against degradation and eliminate some microorganism species at nanomolar concentrations.

Cryptococcus gattii: in vitro susceptibility to photodynamic inactivation.

Cryptococus gattii is an emergent primary human pathogen that causes meningismus, papilledema, high intracranial pressure and focal involvement of the central nervous system in immunocompetent hosts. Prolonged antifungal therapy is the conventional treatment, but it is highly toxic, selects for resistant strains, contributes to therapy failure and has a poor prognosis. Photodynamic inactivation (PDI) offers a promising possibility for the alternative treatment of cryptococcosis. The aim of this study was to test the effectiveness of toluidine blue O (TBO) and light-emitting diode (LED) against C. gattii strains with distinct susceptibility profile to antifungal drugs (amphotericin B: 0.015-1.0 µg mL(-1); itraconazole: 0.015-2 µg mL(-1); fluconazole: 4-64 µg mL(-1)). Using 25 µM (6.76 µg mL(-1)) TBO and LED energy density of 54 J cm(-2) these fungal isolates presented variable susceptibility to PDI. The production of reactive oxygen species (ROS)/peroxynitrite was determined, and the catalase and peroxidase activities were measured. After PDI, high amounts of ROS/peroxynitrite are produced and higher catalase and peroxidase activities could be correlated with a lower susceptibility of C. gattii isolates to PDI. These results indicate that PDI could be an alternative to C. gattii growth inhibition, even of isolates less susceptible to classical antifungal drugs, also pointing to mechanisms related to their variable susceptibility behavior.

Phototoxic action of light emitting diode in the in vitro viability of Trichophyton rubrum / Ação fototóxica do diodo emissor de luz na viabilidade de Trichophyton rubrum in vitro

BACKGROUND: Trichophyton rubrum is the most common agent of superficial mycosis of the skin and nails causing long lasting infections and high recurrence rates. Current treatment drawbacks involve topical medications not being able to reach the nail bed at therapeutic concentrations, systemic antifungal drugs failing to eradicate the fungus before the nails are renewed, severe side effects and selection of resistant fungal isolates. Photodynamic therapy (PDT) has been a promising alternative to conventional treatments. OBJECTIVES: This study evaluated the in vitro effectiveness of toluidine blue O (TBO) irradiated by Light emitting diode (LED) in the reduction of T. rubrum viability. METHODS: The fungal inoculums' was prepared and exposed to different TBO concentrations and energy densities of Light emitting diode for evaluate the T. rubrum sensibility to PDT and production effect fungicidal after photodynamic treatment. In addition, the profiles of the area and volume of the irradiated fungal suspensions were also investigated. RESULTS: A small reduction, in vitro, of fungal cells was observed after exposition to 100 µM toluidine blue O irradiated by 18 J/cm² Light emitting diode. Fungicidal effect occurred after 25 µM toluidine blue O irradiation by Light emitting diode with energy density of 72 J/cm². The analysis showed that the area and volume irradiated by the Light emitting diode were 52.2 mm² and 413.70 mm³, respectively. CONCLUSION: The results allowed to conclude that Photodynamic therapy using Light emitting diode under these experimental conditions is a possible alternative approach to inhibit in vitro T. rubrum and may be a promising new treatment for dermatophytosis caused by this fungus.

FUNDAMENTOS: Trichophyton rubrum é o agente mais comum das micoses superficiais de pele e unhas causando infecções de longa duração e altas taxas de recidiva. As desvantagens do tratamento atual envolvem medicações tópicas as quais não são capazes de alcançar o leito ungueal em concentrações terapêuticas, antifúngicos sistêmicos que não erradicam o fungo antes das unhas serem renovadas, efeitos colaterais graves e seleção de isolados fúngicos resistentes. A terapia fotodinâmica tem sido uma alternativa promissora aos tratamentos convencionais. OBJETIVOS: Este estudo avaliou a eficácia, in vitro, de azul de orto-toluidina irradiado por diodo emissor de luz na redução da viabilidade de T. rubrum. MÉTODOS: O inóculo fúngico foi preparado e exposto a diferentes concentrações de azul de orto-toluidina e densidades de energia do diodo emissor de luz, para avaliar a sensibilidade de T. rubrum e o efeito fungicida, após terapia fotodinâmica. Além disso, os perfis da área e volume das suspensões fúngicas irradiados também foram investigados. RESULTADOS: Uma pequena redução, in vitro, de células fúngicas foi observada após a exposição a 100 mM azul de orto-toluidina irradiados por diodo emissor de luz a 18 J/cm². Efeito fungicida ocorreu após irradiação 25 µM orto-toluidina por diodo emissor de luz com densidade de energia de 72 J/cm². A análise mostrou que a área e o volume irradiados pelo diodo emissor de luz foram 52,2 mm² e 413,70 mm³, respectivamente. CONCLUSÕES: Os resultados permitiram concluir que a terapia fotodinâmica com diodo emissor de luz, nas condições experimentais é uma abordagem alternativa para inibir, in vitro, T. rubrum e pode ser um tratamento promissor para as dermatofitoses causadas por este fungo.

Avaliação das superfícies de implantes dentários com tratamento a laser / Evaluation of dental implant surfaces with laser treatment

O objetivo deste trabalho foi apresentar uma revisão da literatura sobre superfícies de implantes dentários com tratamento a laser. O laser é uma amplificação da luz que, dependendo de sua intensidade e interação com a matéria, é capaz de gerar mudanças morfológicas e químicas em ligas de metais, como as de titânio, usadas em Odontologia. Diversos tipos de tratamentos a laser vêm sendo estudados para criar superfícies rugosas em implantes dentais osseointegráveis. Atualmente, as superfícies rugosas de implantes dentários, comparadas às superfícies usinadas, apresentam melhor resposta biológica do hospedeiro, diminuindo o período de osseointegração e permitindo ao profissional que realize reabilitações protéticas mais rápidas e seguras.

The aim of this work is to present a literature review regarding dental implants surfaces treated by lasers. Laser is a light amplifi cation that depending of the intensity and matter interaction, is capable to cause morphologic and chemical changes in metal alloys, such as, titanium alloy used in dentistry. Several types of surface laser treatments has been studied to create rough surfaces in osseointegrated dental implants. In the last few years, the rough surfaces of dental implants compared to machined surfaces, presented better biologic response of the host, reducing the osseointegration period, enabling professionals to have a possibility to perform faster and more secure prosthodontic rehabilitation.

Terapia fotodinâmica antimicrobiana no tratamento de candidíase em paciente com prótese total mucossuportada superior - relato de caso / Candidiasis treatment with antimicrobial photodynamic therapy in patient with upper complete denture - case report

As próteses totais mucossuportada têm por objetivo reabilitar o sistema estomatognótico de pacientes desdentados totais, restabelecendo a saúde das estruturas de suporte bucais. Apesar da constante busca pela perfeição na confecção de próteses totais, lesões como a Candidíase podem estar associadas ao seu uso. O objetivo deste trabalho foi apresentar um caso clínico de estomatite protética tratada por meio da Terapia Fotodinâmica Antimicrobiana (aPDT), associada ao tratamento protético. O presente estudo mostrou que a luz emitida pelo laser associada ao CHIMIOLUX© foi eficiente em reduzir o número de células de C. albicans e regredir as manifestações clínicas da candidíase atrófica crônica. Assim, aPDT pode ser considerada uma alternativa viável ao tratamento coadjuvante para as lesões fúngicas intraorais e alternativa terapêutica para desinfecção de PTM. Apesar da eficiência da aPDT, a necessidade de orientar o paciente quanto … mudança de hábitos de higiene bucal e utilização de próteses adaptadas são de grande importância na manutenção da saúde dos tecidos orais

Complete mucous membrane-supported dentures aim to rehabilitate the stomatognathic system of edentulous patients, restoring oral health. Even with a constant search to improve complete dentures’ manufacturing process some adverse effects such as candidiasis may still occur. The aim of this study was to present a clinical case of denture stomatitis treated by Antimicrobial Photodynamic Therapy (aPDT), associated with prosthetic treatment. This study showed that the laser light associated with CHIMIOLUX© is effective in reducing the number of cells of C. albicans and to reverse clinical manifestations of chronic atrophic candidiasis. Thus, the aPDT can be considered a viable alternative to adjuvant treatment for denture stomatitis caused by C. albicans and to reverse clinical manifestations of chronic atrophic candidiasis. The aPDT can also be used for disinfection of complete dentures. Despite the efficiency of the aPDT, counseling the patients about oral hygiene and the use of adapted prostheses has great importance in preserving the health of oral tissues

A terapia fotodinâmica antimicrobiana como opção de tratamento não invasivo da periimplantite - revisão de literatura / Antimicrobiaf photodynamic therapy fike an option to peri-impfantitis non- invasive treatment - A literature's review

A peri-implantite é uma doença bacteriana infecciosa que ataca principalmente a região circundante aos implantes dentários osseointegrados. Uma das consequências da peri-implantite é a perda óssea progressiva e até a perda do implante, por isso a importância de que seja tratada com eficiência. Entre os tratamentos possíveis estão os convencionais, que podem ser químicos (antibioticoterapia) ou mecânicos (raspagem local), e pela Terapia Fotodinâmica Antimicrobiana (aPDT), que se apresenta como uma nova alternativa para o tratamento dessas infecções. No intuito da obtenção de maior eficácia no tratamento, estas terapias podem ser utilizadas em conjunto. O tratamento convencional associado ou não a antibióticos não é capaz de eliminar todos os microrganismos instalados na peri-implantite e a aPDT tem sido empregada nestes casos para aumentar a atividade antimicrobiana. Alguns dos microrganismos encontrados na peri-implantite são: Porphyromonas gingivalis, Prevotela intermedia e Aggregatibacter actinomycetemcomitans. A aPDT consiste no uso do laser de baixa intensidade associada a um agente fotossensibilizador diretamente no local da infecção que origina uma reação com formação de espécies reativas de oxigênio que são citotóxicas para os microrganismos patógenos com redução microbiana local

Peri-implantitis is an infectious disease which attacks principally regions adjacent to osteointegrated dental implants. One result of peri-implantitis is progressive bone loss, and implant loss, which the reason for the importance of efficacy treatment Several methods of treatment are used: conventional, in which certain chemicals are used like therapy with antibiotics, mechanical (local scaling) or Antimicrobial Photodynamic Therapy which is a new approach to the treatment of implant infection. To obtain a greater efficacy in treatment therapies can be combined. Conventional treatment combined or not with antibiotics is not able toeliminate all microorganisms in peri-implantitis; there for, Photodynamic Therapy is employed in such cases in order to raise antimicrobial activity Some of the microorganisms found in peri-implantitis are: Porphyromonas gingivalis, Prevotela intermedia and Aggregatibacter actinomycetemcomitans. Photodynamic Therapy consists in using low intensity laser associated with a photosensitizer focused directly on the infected area. This application creates a reaction with the formation of reactive oxygen, which is citotoxical to pathogens thus reducing local microbials.

Efeitos da terapia fotodinâmica no tratamento não cirúrgico da periodontite crônica / Effects of photodynamic therapy in non-surgical treatment of chornic periodontitis

Apesar da terapia periodontal não cirúrgica mostrar resultados significativos na grande maioria dos casos de periodontite crônica, nenhuma das técnicas atualmente disponíveis são eficazes para eliminar totalmente as bactérias subgengivais. Novas terapias antimicrobianas coadjuvantes ao tratamento mecânico têm sido propostas, como o uso de antimicrobianos ou antissépticos locais ou sistêmicos e, neste contexto, se insere a terapia fotodinâmica (PDT, do inglês photodynamic therapy). Sendo assim, 0 objetivo do presente estudo foi avaliar clinicamente os efeitos da terapia fotodinâmica no tratamento não cirúrgico da periodontite crônica.