title: Effects of erbium, chromium:YSGG laser irradiation on root surface: morphological and atomic analytical studies.
abstract: OBJECTIVE
  The purpose of this study was to investigate the morphological and atomic changes on the root surface by stereoscopy, field emission-scanning electron microscopy (FE-SEM), and energy dispersive X-ray spectroscopy (SEM-EDX) after erbium, chromium:yttrium, scandium, gallium, garnet (Er,Cr:YSGG) laser irradiation in vitro.
  
  
  BACKGROUND
  There have been few reports on morphological and atomic analytical study on root surface by Er,Cr:YSGG laser irradiation.
  
  
  METHODS
  Eighteen extracted human premolar and molar teeth were irradiated on root surfaces at a vertical position with water-air spray by an Er,Cr:YSGG laser at the parameter of 5.0 W and 20 Hz for 5 sec while moving. The samples were then morphologically observed by stereoscopy and FE-SEM and examined atomic-analytically by SEM-EDX.
  
  
  RESULTS
  Craters having rough but clean surfaces and no melting or carbonization were observed in the samples. An atomic analytical examination showed that the calcium ratio to phosphorus showed no significant changes between the control and irradiated areas (p > 0.01).
  
  
  CONCLUSIONS
  These results showed that the Er,Cr:YSGG laser has a good cutting effect on root surface and causes no burning or melting after laser irradiation.
authors.affiliation: Department of Endodontics, Showa University School of Dentistry, Tokyo, Japan. yukimura@senzoku.showa-u.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Kimura
authors.forename: D G
authors.initials: DG
authors.lastname: Yu
authors.forename: J
authors.initials: J
authors.lastname: Kinoshita
authors.forename: M
authors.initials: M
authors.lastname: Hossain
authors.forename: K
authors.initials: K
authors.lastname: Yokoyama
authors.forename: Y
authors.initials: Y
authors.lastname: Murakami
authors.forename: K
authors.initials: K
authors.lastname: Nomura
authors.forename: R
authors.initials: R
authors.lastname: Takamura
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D002118:Calcium / Q000032:analysis; D003737:Dental Cavity Preparation / Q000295:instrumentation*; D004577:Electron Probe Microanalysis; D006801:Humans; D007834:Lasers; D008855:Microscopy, Electron, Scanning / Q000379:methods; D010758:Phosphorus / Q000032:analysis; D010780:Photogrammetry; D018709:Statistics, Nonparametric; D014092:Tooth Root / Q000528:radiation effects*
chemical_list: D010758:Phosphorus; D002118:Calcium