title: Tooth discoloration induced by calcium-silicate-based pulp-capping materials.
abstract: OBJECTIVE
  The aim of this study was to evaluate tooth discoloration induced by contact with various calcium silicate-based pulp capping materials in the presence or absence of blood in vitro.
  
  
  METHODS
  Eighty bovine samples were divided into six experimental groups and two control groups according to the type of material used (ProRoot [PR], Endocem [EC], or EndocemZr [ECZ]) and the presence or absence of contamination with blood. A spectrophotometer was used to calculate the color difference (ΔE) between the baseline measurement (after placement of materials) and measurements taken 1, 2, 4, and 8 weeks. The results were analyzed with repeated measures analysis of variance, Tukey's post-hoc tests and independent t-tests (P = 0.05).
  
  
  RESULTS
  The PR group and EC group showed significantly higher mean values of ΔE than the negative control group after 2 weeks (P < 0.05), whereas ECZ did not. There were larger ΔE values when there was contact with blood, especially in PR and EC group (P < 0.05).
  
  
  CONCLUSIONS
  ECZ which contains zirconium oxide as a radiopacifier showed less discoloration irrespective of blood contamination compared to PR and EC.
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Wonkwang University, Iksan, Korea.
authors.forename: Da-A
authors.initials: DA
authors.lastname: Yun
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Wonkwang University, Iksan, Korea.
authors.forename: Su-Jung
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Wonkwang University, Iksan, Korea.
authors.forename: Seok-Ryun
authors.initials: SR
authors.lastname: Lee
authors.affiliation: Department of Conservative Dentistry, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju, Korea.|Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Korea.
authors.forename: Kyung-San
authors.initials: KS
authors.lastname: Min
keywords: Calcium silicate; pulp capping; radiopacifier; tooth discoloration; zirconium