title: Effects of treatment for manipulation of teeth and Er:YAG laser irradiation on dentin: a Raman spectroscopy analysis.
abstract: OBJECTIVE
  The main purpose of this study was to evaluate the utility of Raman spectroscopy analysis as a research tool to study the effects of Er:YAG laser etching on dentin mineral and organic components. A secondary aim was to study the effects of the decontamination process and the storage procedure on dentin components.
  
  
  BACKGROUND
  There are no spectroscopy reports relating the effects of Er:YAG laser irradiation as an alternative to acid etching and the manipulation process on the dentin structure.
  
  
  METHODS
  Twelve non-carious human third molars were divided in two main groups: stored in thymol solution (group A, n = 6) or autoclaved (group B, n = 6). The specimens were either etched with 37% phosphoric acid (control subgroup) or irradiated with Er:YAG laser. Irradiated samples were divided into the following subgroups: I, II, and III (80 mJ, 3 Hz, 30 sec; 120 mJ, 3 Hz, 30 sec; and 180 mJ, 3 Hz, 30 sec, respectively). Samples were analyzed by Raman spectroscopy.
  
  
  RESULTS
  The mineral and organic dentin contents were more affected in autoclaved teeth than in the specimens stored in thymol. Peak area reduction in group A specimens treated with phosphoric acid and pulse energy of 80 mJ were the most conservative surface treatments regarding changes in the peak area of organic and inorganic dentin components.
  
  
  CONCLUSIONS
  The autoclaving process and pulse energies of 120 and 180 mJ produced greater reduction of organic and inorganic contents in dentin, associated with greater reduction in the areas of 968, 1077, 1460, and 1670 cm(1) Raman peaks.
authors.affiliation: Biomedic Vibrational Spectroscopy Laboratory, Research and Development Institute, Universidade do Vale do Paraíba (UNIVAP), São José dos Campos, Brazil.
authors.forename: Luís Eduardo Silva
authors.initials: LE
authors.lastname: Soares
authors.forename: Aldo
authors.initials: A
authors.lastname: Brugnera Junior
authors.forename: Fátima Antônia Aparecida
authors.initials: FA
authors.lastname: Zanin
authors.forename: Marcos Tadeu Tavares
authors.initials: MT
authors.lastname: Pacheco
authors.forename: Airton Abrahão
authors.initials: AA
authors.lastname: Martin
mesh_terms: D045662:Dental Etching / Q000379:methods*; D003804:Dentin / Q000528:radiation effects*; D006801:Humans; D007834:Lasers; D008964:Molar, Third / Q000528:radiation effects; D013059:Spectrum Analysis, Raman; D046509:Tissue Culture Techniques