title: Early and long-term wear of 'fast-set' conventional glass-ionomer cements.
abstract: OBJECTIVE
  Fast setting high viscous glass-ionomer cements have been introduced to reach the set state sooner and to improve early mechanical properties. The aim of this study was to investigate whether 'fast-set' cements have improved the early three-body wear.
  
  
  METHODS
  The three-body wear of four glass-ionomer cements was measured after 1, 4, 7, 30, 90, and 365 days. The chemical composition of the cements was determined with EDAX. The particle size of the powders was determined with a Mastersizer 2000.
  
  
  RESULTS
  The three-body wear of Fuji IX Fast was only slightly less than that of 'regular-set' Fuji IX, but Ketac Molar Quick showed a higher wear compared to the regular-set Ketac Molar. The wear rate of all four glass-ionomer cements decreased over a period of 1 year and could be described by second order reaction kinetics and depended on polyalkenoic acid content, chemical composition, and the size of the glass particles.
  
  
  CONCLUSIONS
  Based on the results of this laboratory study on long-term wear, the glass-ionomer cements investigated may compete with composites, but the early wear characteristics should be further improved. Furthermore, a better understanding of the wear and reaction behavior of glass-ionomer cements is obtained.
authors: Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Louwesweg 1, 1066 EA Amsterdam, The Netherlands.
authors: Raimond N B
authors: RN
authors: van Duinen
authors: Cornelis J
authors: CJ
authors: Kleverlaan
authors: Anton J
authors: AJ
authors: de Gee
authors: Arie
authors: A
authors: Werner
authors: Albert J
authors: AJ
authors: Feilzer
mesh_terms: D004577:Electron Probe Microanalysis; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D010316:Particle Size; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D014783:Viscosity
chemical_list: D005899:Glass Ionomer Cements; C454800:Ketac-Molar Quick; C110713:fuji IX; C110712:ketac-molar