In vitro evaluation of the effects of low-intensity Nd:YAG laser irradiation on the inflammatory reaction elicited by bacterial lipopolysaccharide adherent to titanium dental implants.
BACKGROUND
The bacterial endotoxin lipopolysaccharide (LPS) represents a prime pathogenic factor of peri-implantitis because of its ability to adhere tenaciously to dental titanium implants. Despite this, the current therapeutic approach to this disease remains based mainly on bacterial decontamination, paying little attention to the neutralization of bioactive bacterial products. The purpose of the present study was to evaluate whether irradiation with low-energy neodymium-doped:yttrium, aluminum, and garnet (Nd:YAG) laser, in addition to the effects on bacterial implant decontamination, was capable of attenuating the LPS-induced inflammatory response.


METHODS
RAW 264.7 macrophages or human umbilical vein endothelial cells were cultured on titanium disks coated with Porphyromonas gingivalis LPS, subjected or not to irradiation with the Nd:YAG laser, and examined for the production of inflammatory cytokines and the expression of morphologic and molecular markers of cell activation.


RESULTS
Laser irradiation of LPS-coated titanium disks significantly reduced LPS-induced nitric oxide production and cell activation by the macrophages and strongly attenuated intercellular adhesion molecule-1 and vascular cell adhesion molecule expression, as well as interleukin-8 production by the endothelial cells.


CONCLUSIONS
By blunting the LPS-induced inflammatory response, Nd:YAG laser irradiation may be viewed as a promising tool for the therapeutic management of peri-implantitis.
Giannelli
Marco
M
Department of Odontostomatology, University of Florence, Florence, Italy.
Bani
Daniele
D
Tani
Alessia
A
Pini
Alessandro
A
Margheri
Martina
M
Zecchi-Orlandini
Sandra
S
Tonelli
Paolo
P
Formigli
Lucia
L
D000818:Animals; D002460:Cell Line; D048429:Cell Size / Q000187:drug effects / Q000528:radiation effects; D002478:Cells, Cultured; D016207:Cytokines / Q000187:drug effects / Q000528:radiation effects; D015921:Dental Implants / Q000382:microbiology*; D003764:Dental Materials; D042783:Endothelial Cells / Q000187:drug effects / Q000528:radiation effects*; D004730:Endothelium, Vascular / Q000166:cytology; D005455:Fluorescent Antibody Technique; D015726:Giant Cells / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000187:drug effects / Q000528:radiation effects; D016209:Interleukin-8 / Q000187:drug effects / Q000528:radiation effects; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008070:Lipopolysaccharides / Q000494:pharmacology* / Q000528:radiation effects; D008262:Macrophage Activation / Q000528:radiation effects; D008264:Macrophages / Q000187:drug effects / Q000528:radiation effects*; D051379:Mice; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D009569:Nitric Oxide / Q000528:radiation effects; D016966:Porphyromonas gingivalis / Q000502:physiology*; D011829:Radiation Dosage; D014025:Titanium; D014471:Umbilical Veins / Q000166:cytology; D019010:Vascular Cell Adhesion Molecule-1 / Q000187:drug effects / Q000528:radiation effects
D016207:Cytokines; D015921:Dental Implants; D003764:Dental Materials; D016209:Interleukin-8; D008070:Lipopolysaccharides; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; D009569:Nitric Oxide; D014025:Titanium