title: Evaluation of low-level laser therapy of osteoblastic cells.
abstract: OBJECTIVE
  The purpose of the present study was to evaluate the effect of biomodulation on osteoblastic cells using a gallium-aluminium-arsenide diode laser.
  
  
  BACKGROUND
  Low-level laser therapy (LLLT) is a non-pharmacological therapeutic resource to which biological tissues respond well, producing such effects as the acceleration of bone formation and bone repair.
  
  
  METHODS
  Osteoblastic cell cultures (OFCOL II) were irradiated with a gallium-aluminium-arsenide diode laser (GaAlAs lambda = 830 nm; 50 mW; 3 J/cm(2); 600-microm-diameter optical fiber) and divided into two groups: group 1--irradiated cells, and group 2--non-irradiated cells. Irradiation occurred at 24-h intervals for a total of 3 d. After each interval, the cells were marked with Mito Tracker Orange dye to assess the biostimulatory effect on mitochondrial activity and cell proliferation using an MTT assay.
  
  
  RESULTS
  Intense grouping of mitochondria in the perinuclear region was observed at 24 h and 48 h following irradiation. Changes from a filamentous to a granular appearance in mitochondrial morphology and mitochondria distributed throughout the cytoplasm were observed 72 h following proliferation. Such changes led to an in vitro proliferation process, as confirmed by the MTT assay.
  
  
  CONCLUSIONS
  LLLT has shown itself capable of altering mitochondrial activity and the population of OFCOL II cells.
authors.affiliation: Laboratório de Dinâmica de Compartimentos Celulares, Instituto de Pesquisa e Desenvolvimento, UNIVAP, São José dos Campos, São Paulo, Brazil.
authors.forename: Deise A A
authors.initials: DA
authors.lastname: Pires Oliveira
authors.forename: Rodrigo Franco
authors.initials: RF
authors.lastname: de Oliveira
authors.forename: Renato Amaro
authors.initials: RA
authors.lastname: Zangaro
authors.forename: Cristina Pacheco
authors.initials: CP
authors.lastname: Soares