title: Novel Broad-Spectrum Antimicrobial Photoinactivation of In Situ Oral Biofilms by Visible Light plus Water-Filtered Infrared A.
abstract: Antimicrobial photodynamic therapy (APDT) has gained increased attention as an alternative treatment approach in various medical fields. However, the effect of APDT using visible light plus water-filtered infrared A (VIS + wIRA) on oral biofilms remains unexplored. For this purpose, initial and mature oral biofilms were obtained in situ; six healthy subjects wore individual upper jaw acrylic devices with bovine enamel slabs attached to their proximal sites for 2 h or 3 days. The biofilms were incubated with 100 μg ml(-1) toluidine blue O (TB) or chlorin e6 (Ce6) and irradiated with VIS + wIRA with an energy density of 200 mW cm(-2) for 5 min. After cultivation, the CFU of half of the treated biofilm samples were quantified, whereas following live/dead staining, the other half of the samples were monitored by confocal laser scanning microscopy (CLSM). TB- and Ce6-mediated APDT yielded a significant decrease of up to 3.8 and 5.7 log10 CFU for initial and mature oral biofilms, respectively. Quantification of the stained photoinactivated microorganisms confirmed these results. Overall, CLSM revealed the diffusion of the tested photosensitizers into the deepest biofilm layers after exposure to APDT. In particular, Ce6-aided APDT presented elevated permeability and higher effectiveness in eradicating 89.62% of biofilm bacteria compared to TB-aided APDT (82.25%) after 3 days. In conclusion, antimicrobial photoinactivation using VIS + wIRA proved highly potent in eradicating oral biofilms. Since APDT excludes the development of microbial resistance, it could supplement the pharmaceutical treatment of periodontitis or peri-implantitis.
authors.affiliation: Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Albert-Ludwigs-University, Freiburg, Germany lamprini.karygianni@uniklinik-freiburg.de.
authors.forename: L
authors.initials: L
authors.lastname: Karygianni
authors.affiliation: Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Albert-Ludwigs-University, Freiburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Ruf
authors.affiliation: Department of Hematology and Oncology, Core Facility, Albert-Ludwigs-University, Freiburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Follo
authors.affiliation: Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Albert-Ludwigs-University, Freiburg, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Hellwig
authors.affiliation: Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Albert-Ludwigs-University, Freiburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Bucher
authors.affiliation: Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Albert-Ludwigs-University, Freiburg, Germany.
authors.forename: A C
authors.initials: AC
authors.lastname: Anderson
authors.affiliation: Institute for Medical Biometry and Statistics, Center for Medical Biometry and Medical Informatics, Albert-Ludwigs-University, Freiburg, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Vach
authors.affiliation: Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Albert-Ludwigs-University, Freiburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Al-Ahmad
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism; D001419:Bacteria / Q000528:radiation effects*; D018407:Bacterial Physiological Phenomena / Q000528:radiation effects*; D018441:Biofilms / Q000528:radiation effects*; D002417:Cattle; D015169:Colony Count, Microbial; D064368:Healthy Volunteers; D006801:Humans; D007259:Infrared Rays; D008027:Light; D050296:Microbial Viability / Q000528:radiation effects*; D009055:Mouth / Q000382:microbiology*; D010778:Photochemotherapy / Q000379:methods; D017319:Photosensitizing Agents / Q000378:metabolism; D013194:Staining and Labeling; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D017319:Photosensitizing Agents