Root canal disinfection is one of the main factors governing success of endodontic therapy. Antimicrobial Photodynamic therapy (aPDT) is presented as a promising antimicrobial therapy that can eliminate microbiota present in infected root canal systems. In this study, a series of experiments investigated the effects of aPDT on cell viability and biofilm degradation ability of endopathogenic microbiota. Enterococcus faecalis and Pseudomonas aeruginosa strains as the versatile pathogenic microbiota in endodontic infections were used as the tested strains. Curcumin (CUR) and lightemitting diode (LED) were used as the photosensitizer and light source, respectively. The antimicrobial and anti-biofilm effects of CUR-aPDT were assessed by colony forming unit (CFU), and crystal violet assays. CUR-aPDT significantly decreased the CFU/mL count of E. faecalis and P. aeruginosa compared to the control group (P<0. 05). The killing percentage of aPDT was achieved 95. 0% for E. faecalis and 81. 1% for P. aeruginosa. In addition, the biofilm degradation ability of E. faecalis and P. aeruginosa significantly decreased to 41. 2% and 30. 2%, respectively (P<0. 05). According to the results, neither CUR nor LED showed the antimicrobial and anti-biofilm effects when used alone. In conclusion, the results of this study indicated that CUR-aPDT has an appreciable effect on endopathogenic microbiota upon photoactivation.

Photodynamic therapy (PDT) is a comparatively novel therapeutic method involving a safe light source and a light-sensitive substance, termed as photosensitizers (PSs), such as methylene blue (MB), toluidine blue (TBO), sulfonated aluminum phthalocyanine, chlorine derivatives, nontoxic indocyanine green (ICG), and curcumin (CUR). (1) The combination of a nontoxic PS with low-intensity visible light in the presence of oxygen develops reactive oxygen species (ROS) that are toxic and can cause oxidative damage to microorganisms and tumor cells. (2-4) PSs do not induce cytotoxicity but are activated by laser irradiation at a proper wavelength and develop ROS. (5, 6)...

Epigenetics is the study of heritable alterations in gene expression that are not accompanied by the corresponding change in DNA sequence. Three important epigenetic processes regulate gene expression at the level of chromatin including nucleosomal remodeling, DNA methylation, and histone covalent modifications. Chromatin is a highly dynamic structure composed of DNA and protein (histone and non-histone proteins). Histone amino-terminal regions can undergo modification by acetylation, methylation, phosphorylation, ubiquitylation, sumoylation and ADP ribosylation. The enzymes histone acetyl transferase (HAT) and histone deacetylase (HDAC) control the acetylation level of histones and thereby alter gene expression.Many cancers display molecular alterations that change the balance between HAT and HDAC activity. HDACs exert a pro‑oncogenic effect by silencing genes involved in differentiation, apoptosis and cell cycle arrest. Therefore, the inhibition of HDACs is a target for the development of novel anticancer therapy. Histone deacetylase inhibitors (HDACIs) show anticancer activity by promoting acetylation of histones. The effect of HDACI is different such as cell cycle arrest, inhibit DNA repair, and induce apoptosis.Photodynamic therapy is a form of radiation therapy that is composed of three important parts: a photosensitizer, molecular oxygen and light at a specified wavelength for producing reactive oxygen species (ROS), particularly singlet oxygen in tumor cells. The tumor cells would be destroyed by apoptosis and/or necrosis induced by ROS, achieving the goal of local treatment with minimum invasion.Although the role of Photodynamic therapy on the epigenetic process such as DNA methylation and histone deacetylase is unknown, recently some studies demonstrated that the light could control epigenetic regulator such as HDAC enzymes. Eventually, a combination of Photodynamic therapy with epigenetic may be a novel approach for a more tumor-selective treatment.

Over the past two decades, we have witnessed the increasing use of Photodynamic therapy (PDT) in the field of ocular oncology. Based on a review of the literature and our own experience, we herein review the role of PDT for the management of intraocular tumors. The discussion includes two main topics. First, we discuss the application of PDT for benign tumors, including circumscribed choroidal hemangioma, choroidal osteoma, retinal astrocytoma, retinal capillary hemangioma (retinal hemangioblastoma), and retinal vasoproliferative tumor. Second, we assess the role of PDT for malignant tumors, including choroidal melanoma and choroidal metastasis.

Introduction: Oral biofilms, formed by microorganisms such as Streptococcus mutans, Candida albicans, and Enterococcus faecalis, contribute to common dental problems like caries, periodontitis, and peri-implantitis. These biofilms, characterized by a self-produced extracellular matrix, exhibit high resistance to conventional treatments like antibiotics, necessitating alternative therapeutic strategies. This review explores how PDT employs photosensitizers (PS) activated by specific wavelengths of light to generate reactive oxygen species (ROS), which subsequently target microbial cells and disrupt the biofilm matrix.  The aim of his review is to explores the applications and mechanisms of a novel therapeutic approach called Photodynamic therapy (PDT) for biofilm-associated infections in dentistry. Method: The review also provides a comprehensive overview of both in vitro and clinical studies demonstrating the efficacy of PDT. Results: PDT with photosensitizers such as methylene blue and toluidine blue, combined with light sources such as diode lasers, results in a significant reduction in microbial viability in biofilms. Through the mechanism of ROS production, Photodynamic therapy disrupts biofilm integrity and inactivates microbial pathogens. Furthermore, studies show that combining Photodynamic therapy with conventional treatments such as chlorhexidine or low-dose antibiotics enhances biofilm elimination by exploiting synergistic effects. Conclusion: Advances in nanotechnology, including nanoparticle-encapsulated photosensitizers, are also discussed for their potential to increase the clinical efficacy and specificity of PDT. Through a comprehensive review of current research, this article seeks to highlight the potential of PDT to revolutionize oral care by providing a minimally invasive solution for persistent and resistant dental biofilms.

Oral cavity cancer is a major global problem exacerbated by the use of tobacco, habits such as Paan chewing, and alcohol consumption. There is clearly a need for a preventative program, however, most cases present with advanced disease and in this scenario, despite advances in reconstruction and radiotherapy delivery, little impact has been made on survival.Photodynamic therapy (PDT) is a treatment that involves an oxygen-dependent photochemical reaction that produces cell death by a combination of apoptosis and vascular damage. A series of studies demonstrated treatment safety with good healing, no nerve damage, safety in close proximity to major blood vessels in the head and neck and subsequent clinical trials have duplicated these effects in humans.There have been many studies on all aspects of head and neck cancer from dysplasia through to palliative treatment of advanced disease and these will be presented.The exact future of PDT is a little unclear. It has been widely used in China, Russia Indonesia, and South America but has faced opposition in Europe from pharmaceutical companies, conservative surgeons and, radiation oncologists. However, it should not be seen as a competitor to established therapies but rather as an adjunct.Finally, there are many applications of PDT in benign disease and probably most importantly in antimicrobial action.