title: Changes of Surface Properties of Composite Preveneered Stainless Steel Crowns After Prophy Polishing to Remove Stains.
abstract: OBJECTIVE
  The purpose of this study was to assess the effect of fine-, medium-, and coarse-grit prophy paste used to polish grape juice-stained preveneered stainless steel crowns (PvSSCs).
  
  
  METHODS
  Forty-five maxillary central incisor PvSSCs were immersed in grape juice for 30 days and randomly assigned to three groups (<small>n</small> equals 15) using fine-, medium-, and coarse-grit prophy paste for polishing. Color measurement (L*a*b*), surface roughness (Ra), and scanning electron microscopy imaging were performed at prestain, poststain, and postpolish periods. The significance level was P<.05.
  
  
  RESULTS
  From prestain to poststain, the change in color (ΔE) was 5.4; poststain to postpolish it was 4.7. The overall ΔE value from prestain to postpolish was 1.7, meaning that there was no overall perceivable color change. There was no significant color difference among the three grit groups. The Ra value of prestain (0.047 μm) and poststain (0.050 μm) were significantly lower than postpolish (0.209 μm; P<.001). After polishing, the mean Ra value of the fine-grit polish was 0.164 μm; for the medium-grit polish, it was 0.229 μm; and for the coarse-grit polish, it was 0.232 μm.
  
  
  CONCLUSIONS
  The composite facings were susceptible to grape juice stains, and all three grit prophy pastes removed stains equally effectively. A fine-grit prophy paste is preferred over medium- and coarse-grit to minimize the amount of surface roughness change.
authors.affiliation: Private practitioner in Houston, Texas, USA;, Email: kdtruong@gmail.com.
authors.forename: Khanh
authors.initials: K
authors.lastname: Truong
authors.affiliation: Professor and program director, Advanced Education Program in Pediatric Dentistry, in the Department of Pediatric Dentistry, Loma Linda University, Loma Linda, Calif., USA.
authors.forename: Jung-Wei
authors.initials: JW
authors.lastname: Chen
authors.affiliation: Professor of restorative dentistry, in the Department of Pediatric Dentistry, Loma Linda University, Loma Linda, Calif., USA.
authors.forename: Sean
authors.initials: S
authors.lastname: Lee
authors.affiliation: Associate Professor of restorative dentistry, in the Department of Pediatric Dentistry, Loma Linda University, Loma Linda, Calif., USA.
authors.forename: Holli
authors.initials: H
authors.lastname: Riter
mesh_terms: D003116:Color; D003188:Composite Resins; D003442:Crowns; D003775:Dental Polishing; D000067030:Fruit and Vegetable Juices; D008855:Microscopy, Electron, Scanning; D013193:Stainless Steel; D013499:Surface Properties; D027843:Vitis
chemical_list: D003188:Composite Resins; D013193:Stainless Steel