title: Evaluation of Mineral Content and Photon Interaction Parameters of Dental Enamel After Phosphoric Acid and Er:YAG Laser Treatment.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effects of laser and acid etching on the mineral content and photon interaction parameters of dental enamel in human teeth.
  
  
  BACKGROUND
  The composition of dental enamel may vary, especially at the surface, depending on the reactions that occur during dental treatment.
  
  
  METHODS
  Forty maxillary premolars were divided randomly into 2 groups of 20 teeth. In the first group, half of teeth crowns were etched by using 37% phosphoric acid; in the second group, half of teeth crowns were etched by using an erbium:yttrium-aluminum-garnet (Er:YAG) laser. The remaining half crowns in each group were used as untreated controls. We characterized the calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na), and potassium (K) contents in each specimen by using wavelength dispersive X-ray fluorescence spectrometry. The total atomic cross-section ([Formula: see text]), effective atomic number ([Formula: see text]), and electron density (Ne) of the tooth samples were determined at photon energies of 22.1, 25, 59.5, and 88 keV by using a narrow beam transmission method. Data were analyzed statistically by using the Mann-Whitney U test.
  
  
  RESULTS
  The mineral contents after Er:YAG laser and phosphoric acid etching did not differ significantly (p > 0.05), and no significant variation in [Formula: see text], [Formula: see text], or Newas observed.
  
  
  CONCLUSIONS
  Therefore, we conclude that the Er:YAG laser and phosphoric acid systems used in this study did not affect mineral composition or photon interaction parameters of dental enamel.
authors.affiliation: 1 Department of Pedodontics, Faculty of Dentistry, Ordu University , Ordu, Turkey .
authors.forename: Huseyin
authors.initials: H
authors.lastname: Simsek
authors.affiliation: 2 Department of Pedodontics, Faculty of Dentistry, Ataturk University , Erzurum, Turkey .
authors.forename: Taskın
authors.initials: T
authors.lastname: Gurbuz
authors.affiliation: 3 Department of Orthodontics, Faculty of Dentistry, Ordu University , Ordu, Turkey .
authors.forename: Suleyman Kutalmış
authors.initials: SK
authors.lastname: Buyuk
authors.affiliation: 4 Department of Physics, Faculty of Arts and Sciences, Ataturk University , Erzurum, Turkey .
authors.forename: Yuksel
authors.initials: Y
authors.lastname: Ozdemir
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000704:Analysis of Variance; D001641:Bicuspid; D003743:Dental Enamel / Q000187:drug effects* / Q000528:radiation effects; D006801:Humans; D066298:In Vitro Techniques; D053844:Lasers, Solid-State; D010756:Phosphoric Acids / Q000494:pharmacology*; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000494:pharmacology*; D018709:Statistics, Nonparametric
chemical_list: D010756:Phosphoric Acids; D017319:Photosensitizing Agents
keywords: Er:YAG; acid etching; enamel; lasers