title: Effects on Bone Repair of Osteotomy With Drills or With Erbium, Chromium: Yttrium-Scandium-Gallium-Garnet Laser: Histomorphometric and Immunohistochemical Study.
abstract: BACKGROUND
  The erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser has been widely used in the dental clinic; however, few studies have demonstrated the advantages of the use of this laser for bone osteotomies. The purpose of this study is to evaluate and compare the bone repair process of defects generated by the Er,Cr:YSGG laser or conventional drills.
  
  
  METHODS
  Ninety-six rats were divided into two groups of 48 animals (drill group and laser group). After surgical exposure of the right tibia, the animals were subjected to a 2-mm-diameter osteotomy created by conventional drills (drill group) or by the Er,Cr:YSGG laser (laser group). The animals were sacrificed 0, 3, 7, 14, 30, and 60 days after the creation of the defect, and histologic sections were obtained and used for histomorphometric and immunohistochemical analyses for the detection of osteocalcin, osteoprotegerin, receptor activator of nuclear factor κ-B ligand, vascular endothelial growth factor, and caspase-3.
  
  
  RESULTS
  The osteotomy with the drill produced well-delimited and smooth walls, whereas the osteotomies in the laser group were irregular and presented an amorphous basophilic line and bone necrosis that was slowly resorbed during the repair process. Despite these characteristics, bone repair was similar between groups at various time points, and, at 60 days, the defects in both groups were completely repaired by newly formed bone.
  
  
  CONCLUSIONS
  The repair process of osteotomies created by the Er,Cr:YSGG laser, despite producing thermal damage to bone tissue, is comparable to that with conventional drills.
authors.affiliation: Department of Dental Clinic, Dental School, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Jônatas Caldeira
authors.initials: JC
authors.lastname: Esteves
authors.affiliation: Department of Health Sciences, Implantology Postgraduation Course, University Center of Araraquara (UNIARA), Araraquara, São Paulo, Brazil.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: de Souza Faloni
authors.affiliation: Department of Diagnosis and Surgery, Division of Periodontology, Araraquara Dental School, Univ Estadual Paulista (UNESP), Araraquara, São Paulo, Brazil.
authors.forename: Paula Delello
authors.initials: PD
authors.lastname: Macedo
authors.affiliation: Department of Diagnosis and Surgery, Division of Periodontology, Araraquara Dental School, Univ Estadual Paulista (UNESP), Araraquara, São Paulo, Brazil.
authors.forename: Patrícia Borges
authors.initials: PB
authors.lastname: Nakata
authors.affiliation: Department of Diagnosis and Surgery, Division of Periodontology, Araraquara Dental School, Univ Estadual Paulista (UNESP), Araraquara, São Paulo, Brazil.
authors.forename: Rosemary Adriana
authors.initials: RA
authors.lastname: Chierici Marcantonio
authors.affiliation: Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Harvard University, Boston, MA.|Harvard Stem Cell Institute, Cambridge, MA.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Intini
authors.affiliation: Department of Diagnosis and Surgery, Division of Periodontology, Araraquara Dental School, Univ Estadual Paulista (UNESP), Araraquara, São Paulo, Brazil.
authors.forename: Elcio
authors.initials: E
authors.lastname: Marcantonio
mesh_terms: D000818:Animals; D002857:Chromium; D004871:Erbium; D005708:Gallium; D053844:Lasers, Solid-State / Q000627:therapeutic use; D010027:Osteotomy; D051381:Rats; D012538:Scandium; D042461:Vascular Endothelial Growth Factor A; D015019:Yttrium
chemical_list: D042461:Vascular Endothelial Growth Factor A; D002857:Chromium; D015019:Yttrium; D004871:Erbium; D005708:Gallium; D012538:Scandium
keywords: Bone regeneration; lasers, laser therapy; osteotomy; solid-state