title: Effect of therapeutic doses of radiotherapy on the organic and inorganic contents of the deciduous enamel: an in vitro study.
abstract: OBJECTIVE
  This study evaluated the effects of radiotherapy on the composition of deciduous teeth enamel using micro-energy-dispersive X-ray fluorescence and Fourier transform Raman spectroscopy before and after a pH cycling process.
  
  
  METHODS
  Ten deciduous molars were sectioned and divided into two groups (n = 10). The radiotherapy group (RT) was irradiated with 54 Gy at 2 Gy/day, 5 days per week for 5 weeks and 2 days, and the normal group (N) was not irradiated. The RT group was evaluated before radiotherapy (RTb), after radiotherapy (RTa), and after radiotherapy and pH cycling (RTc). The normal group was evaluated before (N) and after pH cycling (Nc). The weight percentage (wt%) of calcium (Ca), phosphorus (P), and organic content; the Ca/P ratio; and the integrated area of the Raman bands relative to the organic, carbonate, and phosphate contents were also evaluated.
  
  
  RESULTS
  The exclusive use of RT reduced the organic content of the enamel (p = 0.000). The RTc group exhibited a decrease in P wt% (p = 0.016), an increase in the Ca/P ratio (p = 0.000), and a reduction in the integrated area of the phosphate band (p = 0.046). An increase in the Ca/P ratio (p = 0.000) and a reduction in the areas of the carbonate and phosphate bands were found in the RTb/RTc treatments.
  
  
  CONCLUSIONS
  RT application at a therapeutic dose reduced the organic content of the deciduous enamel.
  
  
  CONCLUSIONS
  Preventive measures should be included in the patient treatment protocol because of RT-induced chemical changes to the deciduous enamel.
authors.affiliation: School of Dentistry, Universidade Cruzeiro do Sul (Unicsul), R. Galvão Bueno, 868, Liberdade, São Paulo, SP, CEP- 01506-000, Brazil.|Clínicas Oncológicas Integradas (COI), Oral Medicine Service, Av. das Américas, 6205, loja E, Barra da Tijuca, Rio de Janeiro, RJ, CEP- 22793-080, Brazil.
authors.forename: Elza Maria
authors.initials: EM
authors.lastname: de Sá Ferreira
authors.affiliation: Research and Development Institute, IP&D, Laboratory of Biomedical Vibracional Spectroscopy, LEVB, Universidade do Vale do Paraíba (UNIVAP), São José dos Campos, SP, Brazil. lesoares@univap.br.
authors.forename: Luis Eduardo Silva
authors.initials: LE
authors.lastname: Soares
authors.affiliation: Clínicas Oncológicas Integradas (COI), Radiotherapy, Av. das Américas, 6205, loja E, Barra da Tijuca, Rio de Janeiro, RJ, CEP- 22793-080, Brazil.|Instituto Nacional de Câncer (INCA), Cordination of Clinical Research, Rua André Cavalcante, 37, 2º andar, Centro, Rio de Janeiro, RJ, CEP- 20231-050, Brazil.|School of Dentistry, Universidade Federal Fluminense (UFF), R. Mário Santos Braga, 28, Campos do Valonguinho,Centro, Niterói, Rio de Janeiro, RJ, CEP- 24020-150, Brazil.
authors.forename: Héliton Spíndola
authors.initials: HS
authors.lastname: Antunes
authors.affiliation: Faculdade de Odontologia Uniararas (FHO-Uniararas), Cordination of Dental School, Av. Dr. Maximiliano Baruto, 500, Araras, SP, CEP- 13607-339, Brazil.
authors.forename: Sofia Takeda
authors.initials: ST
authors.lastname: Uemura
authors.affiliation: School of Dentistry, Universidade Cruzeiro do Sul (Unicsul), R. Galvão Bueno, 868, Liberdade, São Paulo, SP, CEP- 01506-000, Brazil.
authors.forename: Patrícia
authors.initials: P
authors.lastname: da Silva Barbosa
authors.affiliation: Clínicas Oncológicas Integradas (COI), Oral Medicine Service, Av. das Américas, 6205, loja E, Barra da Tijuca, Rio de Janeiro, RJ, CEP- 22793-080, Brazil.
authors.forename: Hélio Augusto
authors.initials: HA
authors.lastname: Salmon
authors.affiliation: School of Dentistry, Universidade Cruzeiro do Sul (Unicsul), R. Galvão Bueno, 868, Liberdade, São Paulo, SP, CEP- 01506-000, Brazil.
authors.forename: Giselle Rodrigues
authors.initials: GR
authors.lastname: de Sant'Anna
mesh_terms: D003743:Dental Enamel / Q000737:chemistry* / Q000528:radiation effects*; D006258:Head and Neck Neoplasms / Q000532:radiotherapy; D006801:Humans; D066298:In Vitro Techniques; D008963:Molar; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D014094:Tooth, Deciduous
keywords: Deciduous enamel; Energy-dispersive X-ray spectroscopy; Fourier transform Raman spectroscopy; Head and neck cancer; Radiotherapy