title: [Effect of pulsed Nd: YAG laser irradiation on periodontal ligament fibroblast cultures].
abstract: OBJECTIVE
  To evaluate the effect of the pulsed Nd: YAG laser irradiation on the survival rate of human penodontal ligament fibroblast (PDLF) at different power and irradiation time settings, and to compare the morphological change of cells before and after irradiation.
  
  
  METHODS
  The cells were cultured and placed into the 96-well tissue culture plates. Cells were divided into groups according to the irradiation time (10 s, 20 s, 40 s, 60 s) and the output energy (0.5 W, 1.0 W, 1.5 W, 2.0 W, 2.5 W). After the irradiation, the cell number were counted and the survival rates were calculated. The correlation between the survival rate and irradiation time as well as power output was analyzed.
  
  
  RESULTS
  No significant reduction of survival rates were found in 10 s group, as well as in 20 s group with 0.5 W, 1.0 W setting. The increase of the power output and increase of the irradiation time caused significant reduction of cell survival rate (P <0.05). The irradiation time was more relevant to this reduction than the power output.
  
  
  CONCLUSIONS
  It indicates that the laser irradiation may cause damage to PDLF and decrease the cell survival rate. The irradiation time is more related to this effect than the power output.
authors.affiliation: Dept of Endodontics, West China College of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Mao-bin
authors.initials: MB
authors.lastname: Yang
authors.forename: Yi
authors.initials: Y
authors.lastname: Ding
authors.forename: Jun-qiang
authors.initials: JQ
authors.lastname: Jiang
authors.forename: Hui
authors.initials: H
authors.lastname: Deng
authors.forename: Hua
authors.initials: H
authors.lastname: Tian
mesh_terms: D005347:Fibroblasts; D006801:Humans; D007834:Lasers; D053844:Lasers, Solid-State; D010513:Periodontal Ligament