title: Application of low-level laser irradiation (LLLI) and rhBMP-2 in critical bone defect of ovariectomized rats: histomorphometric evaluation.
abstract: OBJECTIVE
  The aim of this study was to evaluate the osteogenic potential of recombinant human bone morphogenetic protein-2 (rhBMP-2) and low-level laser irradiation (LLLI), isolated or combined in critical bone defects (5 mm) in parietal bone using ovariectomized female rats as an experimental animal model.
  
  
  METHODS
  Forty-nine female Wistar rats, bilaterally ovariectomized (OVX), were divided into seven treatment groups of seven animals each: (I) laser in a single application, (II) 7 μg of pure rhBMP-2, (III) laser and 7 μg of pure rhBMP-2, (IV) 7 μg of rhBMP-2/monoolein gel, (V) laser and 7 μg of rhBMP-2/monoolein gel, (VI) laser and pure monoolein gel, and (VII) critical bone defect controls. The low-level laser source used was a gallium aluminum arsenide semiconductor diode laser device (λ = 780 nm, D = 120 J/cm(2)).
  
  
  RESULTS
  Groups II and III presented higher levels of newly formed bone than all other groups with levels of 40.57% and 40.39%, respectively (p < 0.05). The levels of newly formed bone of groups I, IV, V, and VI were similar with levels of 29.67%, 25.75%, 27.75%, and 30.64%, respectively (p > 0.05). The area of new bone formation in group VII was 20.96%, which is significantly lower than groups I, II, III, and VI.
  
  
  CONCLUSIONS
  It was concluded that pure rhBMP-2 and a single dose of laser application stimulated new bone formation, but the new bone formation area was significantly increased when only rhBMP-2 was used. Additionally, the laser application in combination with other treatments did not influence the bone formation area.
authors.affiliation: University of São Paulo, Ribeirão Preto, Brazil. selmas@forp.usp.br
authors.forename: Selma
authors.initials: S
authors.lastname: Siéssere
authors.forename: Luiz Gustavo
authors.initials: LG
authors.lastname: de Sousa
authors.forename: João Paulo Mardegan
authors.initials: JP
authors.lastname: Issa
authors.forename: Mamie Mizusaki
authors.initials: MM
authors.lastname: Iyomasa
authors.forename: Dimitrius Leonardo
authors.initials: DL
authors.lastname: Pitol
authors.forename: Ana Paula Amorim
authors.initials: AP
authors.lastname: Barbosa
authors.forename: Marisa
authors.initials: M
authors.lastname: Semprini
authors.forename: Walter
authors.initials: W
authors.lastname: Sebald
authors.forename: Maria Vitória Badra
authors.initials: MV
authors.lastname: Bentley
authors.forename: Simone Cecílio Hallak
authors.initials: SC
authors.lastname: Regalo
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology*; D005260:Female; D054023:Lasers, Semiconductor; D028022:Low-Level Light Therapy / Q000379:methods*; D010012:Osteogenesis / Q000187:drug effects* / Q000528:radiation effects*; D010052:Ovariectomy; D010294:Parietal Bone; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D014945:Wound Healing / Q000187:drug effects* / Q000528:radiation effects*
chemical_list: D055396:Bone Morphogenetic Protein 2; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2