title: Colorimeter and scanning electron microscopy analysis of teeth submitted to internal bleaching.
abstract: BACKGROUND
  This in vitro study compared the tooth color and the ultrastructure of internal dental tissues before and after internal bleaching.
  
  
  METHODS
  Sodium perborate was placed in the pulp chamber of endodontically treated molars and sealed with intermediate restorative material. The test samples were stored in a physiologic solution, and the bleaching agent was replaced every 7 days. A control group was used. After 1 month, the colors of the test and control samples were measured with a colorimeter, and the internal surfaces were observed under field emission scanning electron microscopy (FESEM).
  
  
  RESULTS
  Statistically significant differences were found between the test and control sample colors. The FESEM ultrastructure analysis of the internal enamel and dentin surfaces did not show any changes after the internal bleaching.
  
  
  CONCLUSIONS
  The results of the present study show that sodium perborate is effective in bleaching nonvital teeth and does not produce ultrastructural changes in the dental tissues.
authors.affiliation: Division of Pathology and Dental Therapeutics, Department of Operative Dentistry and Endodontics, School of Dentistry, University of Santiago de Compostela, Santiago de Compostela, Galicia, Spain. benjamin.martin@usc.es
authors.forename: Benjamin
authors.initials: B
authors.lastname: Martin-Biedma
authors.forename: Teresa
authors.initials: T
authors.lastname: Gonzalez-Gonzalez
authors.forename: Manuela
authors.initials: M
authors.lastname: Lopes
authors.forename: Luis
authors.initials: L
authors.lastname: Lopes
authors.forename: Rui
authors.initials: R
authors.lastname: Vilar
authors.forename: José
authors.initials: J
authors.lastname: Bahillo
authors.forename: Purificación
authors.initials: P
authors.lastname: Varela-Patiño
mesh_terms: D001881:Borates / Q000627:therapeutic use*; D003124:Colorimetry; D003743:Dental Enamel / Q000187:drug effects / Q000648:ultrastructure; D003786:Dental Pulp Cavity / Q000187:drug effects* / Q000648:ultrastructure; D003804:Dentin / Q000187:drug effects / Q000648:ultrastructure; D006801:Humans; D008334:Mandible; D008963:Molar; D016877:Oxidants / Q000627:therapeutic use; D014073:Tooth Bleaching / Q000379:methods*; D014075:Tooth Discoloration / Q000188:drug therapy*; D019553:Tooth, Nonvital
chemical_list: D001881:Borates; D016877:Oxidants; C027707:sodium perborate