title: Effect of low level diode laser irradiation of human oral mucosa fibroblasts in vitro.
abstract: The effects of low level laser (LLL) irradiation on the proliferation of human buccal fibroblasts were studied. A standardized LLL set-up was developed (812 nm, 4.5 +/- 0.5 mW/cm2). Cultures in petridishes were divided into eight groups (1 group served as control). On day 6 after seeding, routine growth medium was replaced with PBS for 1/2 hour. At the beginning of this period, LLL irradiation was performed for 0, 1, 3, 10, 32, 100, 316, or 1,000 seconds, respectively--corresponding to the radiant exposures 0, 4.5, 13.5, 45, 144, 450, 1,422, 4,500 mJ/cm2. Subsequently the cells received 3H-dT in fresh medium for 16 hours DNA-incorporation. Scintillations from tritium and total protein concentration per culture dish were determined. The individual 3H-cpm/protein-concentration ratios were calculated in % of control. Three experiments were performed (N = 151). Following LLL exposure the 3H-cpm/protein ratio was increased with maximum cpm/protein ratio (132.5% +/- 10.6% SEM) in the group receiving 450 mJ/cm2 (P < 0.03 nonparametric Kruskal Wallis one-way ANOVA-test). This study demonstrated an increased incorporation on tritiated thymidine in cultured human oral fibroblasts following LLL exposure and suggests that LLL irradiation can induce increased DNA synthesis.
authors.affiliation: Department of Oral Pathology, Medicine and Toxicology, Royal Dental College, Faculty of Health Sciences, University of Aarhus, Denmark.
authors.forename: H
authors.initials: H
authors.lastname: Loevschall
authors.forename: D
authors.initials: D
authors.lastname: Arenholt-Bindslev
mesh_terms: D002452:Cell Count; D002470:Cell Survival / Q000528:radiation effects; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology / Q000528:radiation effects*; D006801:Humans; D007834:Lasers; D009061:Mouth Mucosa / Q000528:radiation effects*; D014176:Protein Biosynthesis; D011829:Radiation Dosage