Journal of Research in Dental and Maxillofacial Sciences

en In Vitro Effect of Photodynamic Therapy with 660 nm Diode Laser and Methylene Blue Photosensitizer on Acyclovir-Resistant Herpes Simplex Virus Type 1 Oral medicine Oral medicine Original article Original article <div style="text-align: justify;">Background and Aim: Herpes simplex virus type 1 (HSV-1) is one of the most common infections of the mouth and face. This study was conducted to assess the effect of photodynamic therapy (PDT) with 660 nm diode laser and methylene blue photosensitizer (PS) with different concentrations and radiation parameters on acyclovir-resistant HSV-1.    Materials and Methods: In this in vitro study, first the cytotoxicity of methylene blue for HeLa cells was assessed by the methyl thiazolyl tetrazolium (MTT) assay, and its highest non-toxic concentrations were found (0.001%, 0.002%, 0.005%, and 0.01%). Laser was used with 660 nm wavelength, 100 mW power, and 10, 20, and 30 J/cm2 energy densities for 50, 100, and 150 seconds. The samples were divided into 20 groups, including 12 PDT groups with laser and methylene blue, 3 groups subjected to laser irradiation alone, 4 groups exposed to methylene blue alone with different concentrations, and one negative control group. After laser irradiation, HSV-1 was titrated by the tissue culture infectious dose 50 (TCID50) method. Two-way ANOVA was used for data analysis (alpha=0.05).    Results: The effects of methylene blue concentration (0.001%, 0.002%, 0.005%, and 0.01%) (P=0.675) and laser energy density (10, 20, 30 J/cm2) (P=0.914), and their interaction effect (P=0.977) on the titer of acyclovir-resistant HSV-1 were not significant. Conclusion: PDT with 660 nm laser with different energy densities and different methylene blue concentrations had no significant effect on acyclovir-resistant HSV-1.  </div> Acyclovir, Photochemotherapy, Methylene Blue, Herpes Simplex virus 103 110 http://jrdms.dentaliau.ac.ir/browse.php?a_code=A-10-785-1&slc_lang=en&sid=1 Nazanin Mohitmafi nazaninmohitmafi@yahoo.com 100319475328460014825 100319475328460014825 No Department of Oral and Maxillofacial Medicine, TeMS.C., Islamic Azad University, Tehran, Iran. Masoud Parsania mparsania@iautmu.uc.ir 100319475328460014826 100319475328460014826 No Department of Microbiology, Faculty of Medicine, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. Arezoo Alaee arezoo.alaee@yahoo.com 100319475328460014827 100319475328460014827 No Department of Oral Medicine, Dental Material Research Center, TeMS.C., Islamic Azad University, Tehran, Iran. Pooya Olyaee dr_olyaee@yahoo.com 100319475328460014828 100319475328460014828 No Department of Orthodontics, Urmia University of Medical Science, School of Dentistry, Urmia, Iran. Mohammad Vahedi vahedi_md@yahoo.com 100319475328460014829 100319475328460014829 Yes Department of Oral and Maxillofacial Medicine, TeMS.C., Islamic Azad University, Tehran, Iran.