title: New Irradiation Method with Indocyanine Green-Loaded Nanospheres for Inactivating Periodontal Pathogens.
abstract: Antimicrobial photodynamic therapy (aPDT) has been proposed as an adjunctive strategy for periodontitis treatments. However, use of aPDT for periodontal treatment is complicated by the difficulty in accessing morphologically complex lesions such as furcation involvement, which the irradiation beam (which is targeted parallel to the tooth axis into the periodontal pocket) cannot access directly. The aim of this study was to validate a modified aPDT method that photosensitizes indocyanine green-loaded nanospheres through the gingivae from outside the pocket using a diode laser. To establish this trans-gingival irradiation method, we built an in vitro aPDT model using a substitution for gingivae. Irradiation conditions and the cooling method were optimized before the bactericidal effects onPorphyromonas gingivaliswere investigated. The permeable energy through the gingival model at irradiation conditions of 2 W output power in a 50% duty cycle was comparable with the transmitted energy of conventional irradiation. Intermittent irradiation with air cooling limited the temperature increase in the gingival model to 2.75 °C. The aPDT group showed significant bactericidal effects, with reductions in colony-forming units of 99.99% after 5 min of irradiation. This effect of aPDT against a periodontal pathogen demonstrates the validity of trans-gingival irradiation for periodontal treatment.
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651, Japan. ag143d09@dpc.agu.ac.jp.|Division of Periodontal Health Promotion, Dental Hospital, Aichi Gakuin University, Nagoya, Aichi 464-8651, Japan. ag143d09@dpc.agu.ac.jp.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Sasaki
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651, Japan. jun1row@dpc.agu.ac.jp.
authors.forename: Jun-Ichiro
authors.initials: JI
authors.lastname: Hayashi
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651, Japan. takeki@dpc.agu.ac.jp.|Division of Periodontal Health Promotion, Dental Hospital, Aichi Gakuin University, Nagoya, Aichi 464-8651, Japan. takeki@dpc.agu.ac.jp.
authors.forename: Takeki
authors.initials: T
authors.lastname: Fujimura
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651, Japan. yukiwa@dpc.agu.ac.jp.|Division of Periodontal Health Promotion, Dental Hospital, Aichi Gakuin University, Nagoya, Aichi 464-8651, Japan. yukiwa@dpc.agu.ac.jp.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Iwamura
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651, Japan. genta@dpc.agu.ac.jp.
authors.forename: Genta
authors.initials: G
authors.lastname: Yamamoto
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651, Japan. enishida@dpc.agu.ac.jp.
authors.forename: Eisaku
authors.initials: E
authors.lastname: Nishida
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651, Japan. ag143d03@dpc.agu.ac.jp.
authors.forename: Tasuku
authors.initials: T
authors.lastname: Ohno
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651, Japan. ag133d03@dpc.agu.ac.jp.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Okada
authors.affiliation: Department of Pharmaceutical Engineering, School of Pharmacology, Aichi Gakuin University, Nagoya, Aichi 464-8650, Japan. hiromitu@dpc.agu.ac.jp.
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Yamamoto
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651, Japan. tkikuchi@dpc.agu.ac.jp.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kikuchi
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651, Japan. minita@dpc.agu.ac.jp.
authors.forename: Akio
authors.initials: A
authors.lastname: Mitani
authors.affiliation: Department of Periodontology, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651, Japan. fukuda-m@dpc.agu.ac.jp.|Division of Periodontal Health Promotion, Dental Hospital, Aichi Gakuin University, Nagoya, Aichi 464-8651, Japan. fukuda-m@dpc.agu.ac.jp.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Fukuda
mesh_terms: D065638:Absorption, Radiation; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003080:Cold Temperature; D006801:Humans; D007208:Indocyanine Green / Q000737:chemistry*; D054023:Lasers, Semiconductor; D050296:Microbial Viability; D008954:Models, Biological; D054118:Nanospheres / Q000737:chemistry*; D010518:Periodontitis / Q000382:microbiology* / Q000532:radiotherapy*; D010539:Permeability; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology; D016966:Porphyromonas gingivalis / Q000187:drug effects / Q000528:radiation effects
chemical_list: D000900:Anti-Bacterial Agents; D017319:Photosensitizing Agents; D007208:Indocyanine Green
keywords: diode laser; indocyanine green; photodynamic therapy