title: Effect of low-level laser therapy on bisphosphonate-treated osteoblasts.
abstract: BACKGROUND
  This study investigates the effect of alendronate-treated osteoblasts, as well as the effect of low-level laser therapy (LLLT) on the alendronate-treated osteoblasts. Bisphosphonate decreases the osteoblastic activity. Various treatment modalities are used to enhance the bisphosphonate-treated osteoblasts; however, there were no cell culture studies conducted using a low-level laser.
  
  
  METHODS
  Human fetal osteoblastic (hFOB 1.19) cells were treated with 50 μM alendronate. Then, they were irradiated with a 1.2 J/cm2low-level Ga-Al-As laser (λ= 808 ± 3 nm, 80 mW, and 80 mA; spot size, 1 cm2; NDLux, Seoul, Korea). The cell survivability was measured with the MTT assay. The three cytokines of osteoblasts, receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), and macrophage colony-stimulating factor (M-CSF) were analyzed.
  
  
  RESULTS
  In the cells treated with alendronate at concentrations of 50 μM and higher, cell survivability significantly decreased after 48 h (p< 0.05). After the applications of low-level laser on alendronate-treated cells, cell survivability significantly increased at 72 h (p< 0.05). The expressions of OPG, RANKL, and M-CSF have decreased via the alendronate. The RANKL and M-CSF expressions have increased, but the OPG was not significantly affected by the LLLT.
  
  
  CONCLUSIONS
  The LLLT does not affect the OPG expression in the hFOB cell line, but it may increase the RANKL and M-CSF expressions, thereby resulting in positive effects on osteoclastogenesis and bone remodeling.
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University, Beomeo, Mulgeum, Yangsan, 626-770 Republic of Korea.
authors.forename: Sang-Hun
authors.initials: SH
authors.lastname: Shin
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University, Beomeo, Mulgeum, Yangsan, 626-770 Republic of Korea.
authors.forename: Ki-Hyun
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University, Beomeo, Mulgeum, Yangsan, 626-770 Republic of Korea.
authors.forename: Na-Rae
authors.initials: NR
authors.lastname: Choi
authors.affiliation: Department of Oral Anatomy and Cell Biology, School of Dentistry, Pusan National University, Beomeo, Mulgeum, Yangsan, 626-770 Republic of Korea.
authors.forename: In-Ryoung
authors.initials: IR
authors.lastname: Kim
authors.affiliation: Department of Oral Anatomy and Cell Biology, School of Dentistry, Pusan National University, Beomeo, Mulgeum, Yangsan, 626-770 Republic of Korea.
authors.forename: Bong-Soo
authors.initials: BS
authors.lastname: Park
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University, Beomeo, Mulgeum, Yangsan, 626-770 Republic of Korea.
authors.forename: Yong-Deok
authors.initials: YD
authors.lastname: Kim
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University, Beomeo, Mulgeum, Yangsan, 626-770 Republic of Korea.
authors.forename: Uk-Kyu
authors.initials: UK
authors.lastname: Kim
authors.affiliation: Department of Oral and Maxillofacial Surgery, Dentistry, Dong-A Medical Center, 602-715 Pusan, Republic of Korea.
authors.forename: Cheol-Hun
authors.initials: CH
authors.lastname: Kim
keywords: BRONJ; Bisphosphonate; Low-level laser therapy (LLLT); Osteoblasts