title: Effects of Er:YAG laser on bacteria associated with titanium surfaces and cellular response in vitro.
abstract: This in vitro study examined (a) the anti-bacterial efficacy of a pulsed erbium-doped yttrium aluminum garnet (Er:YAG) laser applied to Streptococcus sanguinis or Porphyromonas gingivalis adhered to either polished or microstructured titanium implant surfaces, (b) the response of osteoblast-like cells and (c) adhesion of oral bacteria to titanium surfaces after laser irradiation. Thereto, (a) bacteria adhered to titanium disks were irradiated with a pulsed Er:YAG laser (λ = 2,940 nm) at two different power settings: a lower mode (12.74 J/cm(2) calculated energy density) and a higher mode (63.69 J/cm(2)). (b) After laser irradiation with both settings of sterile titanium, disks were seeded with 10(4) MG-63 cells/cm(2). Adhesion and proliferation were determined after 1, 4, and 24 h by fluorescence microscopy and scanning electron microscopy. (c) Bacterial adhesion was also studied on irradiated (test) and non-irradiated (control) surfaces. Adhered P. gingivalis were effectively killed, even at the lower laser setting, independent of the material's surface. S. sanguinis cells adhered were effectively killed only at the higher setting of 63.69 J/cm(2). Laser irradiation of titanium surfaces had no significant effects on (b) adhesion or proliferation of osteoblast-like MG-63 cells or (c) adhesion of both oral bacterial species in comparison to untreated surfaces. An effective decontamination of polished and rough titanium implant surfaces with a Er:YAG laser could only be achieved with a fluence of 63.69 J/cm(2). Even though this setting may lead to certain surface alterations, no significant adverse effect on subsequent colonization and proliferation of MG-63 cells or increased bacterial adhesion was found in comparison to untreated control surfaces.
authors.affiliation: Institute of Preventive Dentistry and Oral Microbiology, School of Dental Medicine, University of Basel, Hebelstrasse 3, 4056, Basel, Switzerland, I.Hauser-Gerspach@unibas.ch.
authors.forename: Irmgard
authors.initials: I
authors.lastname: Hauser-Gerspach
authors.forename: Corinna
authors.initials: C
authors.lastname: Mauth
authors.forename: Tuomas
authors.initials: T
authors.lastname: Waltimo
authors.forename: Jürg
authors.initials: J
authors.lastname: Meyer
authors.forename: Stefan
authors.initials: S
authors.lastname: Stübinger
mesh_terms: D001422:Bacterial Adhesion / Q000187:drug effects / Q000528:radiation effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects / Q000528:radiation effects; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D003666:Decontamination; D006801:Humans; D053844:Lasers, Solid-State; D010006:Osteoblasts / Q000166:cytology / Q000528:radiation effects* / Q000648:ultrastructure; D016966:Porphyromonas gingivalis / Q000187:drug effects / Q000528:radiation effects*; D013298:Streptococcus sanguis / Q000187:drug effects / Q000528:radiation effects*; D013499:Surface Properties; D014025:Titanium / Q000494:pharmacology* / Q000528:radiation effects*
chemical_list: D014025:Titanium