title: Nd:YAG laser improves biocompatibility of human dental root surfaces.
abstract: OBJECTIVE
  Our goal was to compare the in vivo biocompatibility of dental root surfaces submitted to four different treatments after tooth avulsion followed by implantation into rat subcutaneous tissue.
  
  
  BACKGROUND
  Dental root surface preparation prior to replanting teeth remains a challenge for endodontists. Root surface changes made by Nd:YAG irradiation could be an alternative preparation.
  
  
  METHODS
  Forty-eight freshly extracted human dental roots were randomly divided into four treatment groups prior to implantation into rat subcutaneous tissue: G1, dry root, left in the environment up to 3 h; G2, the same treatment as G1, followed by a soaking treatment in a 2.4% sodium fluoride solution (pH 5.5); G3, root soaked in physiologic saline after avulsion for 72 h; G4, the same treatment as G1, followed by Nd:YAG laser irradiation (2.0 W, 20 Hz, 100 mJ, and 124.34 J/cm(2)). The animals were sacrificed 1, 7, and 45 d later. Histological and scanning electron microscopy analyses were done.
  
  
  RESULTS
  All dental roots were involved and in intimate contact with connective tissue capsules of variable thicknesses. Differences were observed in the degree of inflammation and in connective tissue maturation. In G3 the inflammatory infiltrate was maintained for 45 d, whereas the Nd:YAG laser irradiation (G4) led to milder responses. The overall aspects of the root surfaces were similar, except by the irradiated roots, where fusion and resolidification of the root surface covering the dentinal tubules were observed.
  
  
  CONCLUSIONS
  Nd:YAG laser irradiation improves the biocompatibility of dental root and thus could be an alternative treatment of dental root prior to replantation.
authors.affiliation: Department of Endodontics, University of Paulista-UNIP, São Paulo, Brazil.
authors.forename: Lení
authors.initials: L
authors.lastname: Hamaoka
authors.forename: Cacio
authors.initials: C
authors.lastname: Moura-Netto
authors.forename: Márcia Martins
authors.initials: MM
authors.lastname: Marques
authors.forename: Abilio Albuquerque Maranhão
authors.initials: AA
authors.lastname: de Moura
mesh_terms: D000818:Animals; D006801:Humans; D053685:Laser Therapy; D053844:Lasers, Solid-State; D008297:Male; D008422:Materials Testing; D051381:Rats; D017208:Rats, Wistar; D040521:Subcutaneous Tissue; D014084:Tooth Avulsion / Q000628:therapy*; D019246:Tooth Preparation / Q000379:methods*; D014090:Tooth Replantation; D014092:Tooth Root / Q000528:radiation effects*