title: The effect of laser therapy on the expression of osteocalcin and osteopontin after tooth extraction in rats treated with zoledronate and dexamethasone.
abstract: OBJECTIVE
  Laser therapy has been used for the prevention and management of medication-related ostenecrosis of the jaw (MRONJ). The aim of this paper was to investigate the action of laser therapy on extraction socket healing in rats in conditions at risk for MRONJ, evaluating the expression of markers of bone metabolism.
  
  
  METHODS
  Thirty male Sprague-Dawley rats were divided in four groups: control group (C, n = 5), laser group (L, n = 5), treatment group (T, n = 10), and treatment plus laser group (T + L, n = 10). Rats of group T and T + L received zoledronate 0.1 mg/kg and dexamethasone 1 mg/kg every 2 days for 10 weeks. Rats of group C and L were infused with vehicle. After 9 weeks, the left maxillary molars were extracted in all rats. Rats of groups L and T + L received laser therapy (Nd:YAG, 1064 nm, 1.25 W, 15 Hz, 5 min, 14.37 J/cm(2)) in the socket area at days 0, 2, 4, and 6 after surgery. Western blot analysis was performed to evaluate the alveolar expression of osteopontin (OPN) and osteocalcin (OCN) 8 days after extraction.
  
  
  RESULTS
  Rats of groups L and T + L showed a significant higher expression of OCN compared to rats of groups C and T (+348 and +400 %, respectively; P = 0.013 and P = 0.002, respectively). The expression of OPN did not show significant differences among the different groups.
  
  
  CONCLUSIONS
  Our findings suggest that laser irradiation after tooth extraction can promote osteoblast differentiation, as demonstrated by the higher expression of OCN. Thus, laser irradiation could be considered a way to improve socket healing in conditions at risk for MRONJ development.
authors.affiliation: Unit of Oral Pathology and Laser-Assisted Oral Surgery, Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Viale Gramsci 14, 43100, Parma, Italy. gmergon@gmail.com.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Mergoni
authors.affiliation: Unit of Oral Pathology and Laser-Assisted Oral Surgery, Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Viale Gramsci 14, 43100, Parma, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Vescovi
authors.affiliation: Unit of General Pathology, Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Sala
authors.affiliation: Unit of Oral Pathology and Laser-Assisted Oral Surgery, Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Viale Gramsci 14, 43100, Parma, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Merigo
authors.affiliation: Unit of Oral Pathology and Laser-Assisted Oral Surgery, Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Viale Gramsci 14, 43100, Parma, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Passerini
authors.affiliation: Unit of Pathology, Department of Biomedical, Biotechnological, and Translational Sciences, University of Parma, Parma, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Maestri
authors.affiliation: Unit of Pathology, Department of Biomedical, Biotechnological, and Translational Sciences, University of Parma, Parma, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Corradi
authors.affiliation: Unit of Anatomy Histology and Embryology, Department of Biomedical, Biotechnological and Translational Sciences (S.Bi.Bi.T), University of Parma, Parma, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Govoni
authors.affiliation: Department of Dental Sciences, Faculty of Medicine, University of Liège, Liège, Belgium.
authors.forename: Samir
authors.initials: S
authors.lastname: Nammour
authors.affiliation: Unit of General Pathology, Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma, Italy.
authors.forename: Massimiliano G
authors.initials: MG
authors.lastname: Bianchi
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology*; D050071:Bone Density Conservation Agents / Q000008:administration & dosage / Q000494:pharmacology*; D003131:Combined Modality Therapy; D003907:Dexamethasone / Q000008:administration & dosage / Q000494:pharmacology*; D004164:Diphosphonates / Q000008:administration & dosage / Q000494:pharmacology*; D007093:Imidazoles / Q000008:administration & dosage / Q000494:pharmacology*; D028022:Low-Level Light Therapy / Q000379:methods*; D008297:Male; D015675:Osteocalcin / Q000378:metabolism*; D010020:Osteonecrosis / Q000517:prevention & control*; D053495:Osteopontin / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014081:Tooth Extraction; D020390:Tooth Socket; D014945:Wound Healing; D000077211:Zoledronic Acid
chemical_list: D000893:Anti-Inflammatory Agents; D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D007093:Imidazoles; D015675:Osteocalcin; D053495:Osteopontin; D000077211:Zoledronic Acid; D003907:Dexamethasone
keywords: Laser therapy; Medication-related osteonecrosis of the jaw; Osteocalcin; Osteopontin; Tooth extraction; Zoledronic acid