title: Sensitivity of Porphyromonas and Prevotella species in liquid media to argon laser.
abstract: The phototoxicity of argon laser irradiation was studied in aqueous suspensions of Porphyromonas endodontalis (American Type Culture Collection [ATCC] 35406), Porphyromonas gingivalis (ATCC 33277), Prevotella denticola (ATCC 33184) and two strains of Prevotella intermedia (ATCC 15033 and 49046), all "black-pigmented bacteria," BPB, that accumulate cellular porphyrins. Several of these species have been implicated in the etiology of periodontal disease. Non-black-pigmented bacteria were also studied to test the specificity of irradiation as a potential photodynamic treatment for periodontal infections. Cell suspensions were irradiated with an argon laser at fluences of 20-200 J/cm2. When cultured in hemin-supplemented media, ATCC 15033 was the most sensitive to irradiation. However, a second strain of the same species (ATCC 49046) was resistant. The photosensitivity of other species ranked ATCC 33277 > 35406 = 33184 = 35496. When hemin was replaced in media by hemoglobin, ATCC 33277 became resistant to irradiation. Protoporphyrin IX content in BPB cells was shown not to be a major factor determining photosensitivity. Oxygen was required during irradiation for BPB species to be affected. Non-black-pigmented bacteria were much less sensitive to irradiation than BPB.
authors.affiliation: Department of Biomedical Sciences, Baylor College of Dentistry, Dallas, TX 75246, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Henry
authors.forename: M
authors.initials: M
authors.lastname: Judy
authors.forename: B
authors.initials: B
authors.lastname: Dyer
authors.forename: M
authors.initials: M
authors.lastname: Wagner
authors.forename: J L
authors.initials: JL
authors.lastname: Matthews
mesh_terms: D001128:Argon; D066298:In Vitro Techniques; D007834:Lasers; D010510:Periodontal Diseases / Q000209:etiology / Q000628:therapy; D010789:Phototherapy; D017861:Porphyromonas / Q000378:metabolism / Q000472:pathogenicity / Q000528:radiation effects*; D018720:Prevotella / Q000378:metabolism / Q000472:pathogenicity / Q000528:radiation effects*; D011524:Protoporphyrins / Q000378:metabolism
chemical_list: D011524:Protoporphyrins; D001128:Argon; C028025:protoporphyrin IX