title: Reactive oxygen species production in mitochondria of human gingival fibroblast induced by blue light irradiation.
abstract: In recent years, it has become well known that the production of reactive oxygen species (ROS) induced by blue-light irradiation causes adverse effects of photo-aging, such as age-related macular degeneration of the retina. Thus, orange-tinted glasses are used to protect the retina during dental treatment involving blue-light irradiation (e.g., dental resin restorations or tooth bleaching treatments). However, there are few studies examining the effects of blue-light irradiation on oral tissue. For the first time, we report that blue-light irradiation by quartz tungsten halogen lamp (QTH) or light-emitting diode (LED) decreased cell proliferation activity of human gingival fibroblasts (HGFs) in a time-dependent manner (<5 min). Additionally, in a morphological study, the cytotoxic effect was observed in the cell organelles, especially the mitochondria. Furthermore, ROS generation induced by the blue-light irradiation was detected in mitochondria of HGFs using fluorimetry. In all analyses, the cytotoxicity was significantly higher after LED irradiation compared with cytotoxicity after QTH irradiation. These results suggest that blue light irradiation, especially by LED light sources used in dental aesthetic treatment, might have adverse effects on human gingival tissue. Hence, this necessitates the development of new dental aesthetic treatment methods and/or techniques to protect HGFs from blue light irradiation during dental therapy.
authors.affiliation: Department of Oral Science, Kanagawa Dental University Graduate School, Yokosuka 238-8580, Japan.
authors.forename: Ayaka
authors.initials: A
authors.lastname: Yoshida
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Yoshino
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Makita
authors.forename: Yojiro
authors.initials: Y
authors.lastname: Maehata
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Higashi
authors.forename: Chihiro
authors.initials: C
authors.lastname: Miyamoto
authors.forename: Satoko
authors.initials: S
authors.lastname: Wada-Takahashi
authors.forename: Shun-suke
authors.initials: SS
authors.lastname: Takahashi
authors.forename: Osamu
authors.initials: O
authors.lastname: Takahashi
authors.forename: Masaichi Chang-il
authors.initials: MC
authors.lastname: Lee
mesh_terms: D002460:Cell Line; D049109:Cell Proliferation / Q000528:radiation effects; D005347:Fibroblasts / Q000166:cytology / Q000528:radiation effects*; D005470:Fluorometry; D005881:Gingiva / Q000166:cytology; D006801:Humans; D008027:Light; D008854:Microscopy, Electron; D008928:Mitochondria / Q000378:metabolism* / Q000528:radiation effects* / Q000648:ultrastructure; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species
keywords: Blue light; Human gingival fibroblast; Light-emitting diode; Mitochondria; Quartz tungsten halogen; Reactive oxygen species