title: Comparative radical production and cytotoxicity induced by camphorquinone and 9-fluorenone against human pulp fibroblasts.
abstract: Camphorquinone (CQ) is widely used as a photo-initiator in dental materials; however, its cytotoxicity against human pulp fibroblasts (HPF) and particularly the effects of 2-dimethylaminoethyl methacrylate (DMA), a reducing agent and visible light (VL) irradiation on it remain unknown. So we investigated the cytotoxic and reactive oxygen species (ROS)-producing effects of CQ with or without DMA, in the presence or absence of VL on HPF cells. The free-radical production activity of CQ was measured by two different methods [using diphenylpicryl hydrazyl and galvinoxyl]. The phase-transition properties of dipalmitoylphosphatidyl choline (DPPC) liposomes, as a model for biomembranes, induced by CQ were investigated by differential scanning calorimetry. These findings were compared with those of 9-fluorenone (9F), an aromatic photo-initiator with long conjugated groups. Camphorquinone with VL irradiation increased the radical production, whereas 9F with VL irradiation increased ROS production, as well as effecting changes in the DPPC phase-transition properties. The cytotoxicity of CQ towards HPF cells was smaller than that of 9F despite greater radical production. The addition of DMA to the photosensitizer enhanced the free-radical production without increasing the ROS level or the cytotoxicity. Camphorquinone/DMA is a valuable combination for the polymerization of dental resins.
authors.affiliation: Department of Oral Physiology, Mekai University School of Dentistry, Sakado, Saitama, Japan. tosi@dent.meikai.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Atsumi
authors.forename: M
authors.initials: M
authors.lastname: Ishihara
authors.forename: Y
authors.initials: Y
authors.lastname: Kadoma
authors.forename: K
authors.initials: K
authors.lastname: Tonosaki
authors.forename: S
authors.initials: S
authors.lastname: Fujisawa
mesh_terms: D016923:Cell Death; D002478:Cells, Cultured; D002675:Child, Preschool; D003782:Dental Pulp / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D005449:Fluorenes / Q000737:chemistry / Q000633:toxicity*; D006801:Humans; D008689:Methacrylates / Q000737:chemistry / Q000633:toxicity; D010775:Photic Stimulation; D017319:Photosensitizing Agents / Q000737:chemistry / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D019163:Reducing Agents / Q000737:chemistry / Q000633:toxicity; D013729:Terpenes / Q000737:chemistry / Q000633:toxicity*
chemical_list: D005449:Fluorenes; D008689:Methacrylates; D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; D019163:Reducing Agents; D013729:Terpenes; C048339:camphoroquinone; C028401:9-fluorenone; C049840:2-(dimethylamino)ethyl methacrylate