title: Management of Post-orthodontic White Spot Lesions and Subsequent Enamel Discoloration with Two Microabrasion Techniques.
abstract: BACKGROUND
  Demineralization of enamel adjacent to orthodontic appliances frequently occurs, commonly due to insufficient oral hygiene.
  
  
  OBJECTIVE
  The aim of this study was to compare two microabrasion techniques on improving the white spot lesions as well as subsequent enamel discoloration.
  
  
  METHODS
  Sixty extracted premolar teeth without caries and hypoplasia were selected for this study. White spot lesions were artificially induced on the buccal surface of each tooth. Teeth were randomly assigned to three treatment groups, each treated with pumice powder as the control, microabrasion with 18% HCl, and microabrasion with 37% H3PO4. Subsequently, the three groups were daily immersed for five minutes in a tea-coffee solution for a period of one week. Colorimetric evaluation was done before and after formation of white spot lesions, after microabrasion, and after immersion in the colored solution; then the color differences (∆E) were calculated. Statistical analysis was performed by multiple measurement analysis and the Tukey's test.
  
  
  RESULTS
  This study showed that ∆E between the stages of white spot formation and microabrasion for H3PO4 was more than other groups and for the pumice powder group it was less than the others. Furthermore, there was a significant difference between ∆E of the three study groups (p= 0.017). Additionally, ∆E after placing the teeth in the colored solution and microabrasion was the highest for the HCl group and the lowest for the pumice powder group. There was also a significant difference between the three groups (p= 0.000).
  
  
  CONCLUSIONS
  Pumice powder alone had similar effects as 18% HCl on removing the white spot lesions. Nevertheless, 18% HCl makes the enamel susceptible for subsequent color staining more than the other microabrasion methods.
authors.affiliation: Dept. of Orthodontics, Dental Research Centre, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran;
authors.forename: Arezoo
authors.initials: A
authors.lastname: Jahanbin
authors.affiliation: Dept. of Restorative Dentistry, Dental Research Centre, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran;
authors.forename: Hamideh
authors.initials: H
authors.lastname: Ameri
authors.affiliation: Dept. of Orthodontics, Dental Research Centre, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran;
authors.forename: Mostafa
authors.initials: M
authors.lastname: Shahabi
authors.affiliation: Dept. of Oral Medicine, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran;
authors.forename: Ala
authors.initials: A
authors.lastname: Ghazi
keywords: Discoloration; Microabrasion; Orthodontics; White Spot Lesion