title: Silica as a reference for laboratory dentifrice assessment methods: multiple site collaborative study.
abstract: OBJECTIVE
  This collaborative study was designed to collect data from multiple laboratories, using recognized abrasion and cleaning power methods, to assess the functionality, stability, and suitability of three Sident silica abrasives for consideration as references for ISO (International Standards Organization) abrasion and other dentifrice assessment methods.
  
  
  METHODS
  This study included ISO and other physicochemical methods to characterize the abrasive powders, as well as ISO and related abrasion methods--Radioactive Dentin Method, Profilometry, and Copper Gravimetric, and two Cleaning Power methods--to test the functionality of the silica abrasives with the current ISO abrasion reference calcium pyrophosphate.
  
  
  RESULTS
  The outcomes demonstrated that the collaborative study to measure the physicochemical characteristics of three Sident silica abrasive materials, stored at ISO and tropical conditions, found no change in the functionality as measured by these methods over the two-year test period.
  
  
  CONCLUSIONS
  The three Sident silica abrasives demonstrated suitability to be considered as references for use with calcium pyrophosphate in the ISO 11609 Toothpaste Specification.
authors.affiliation: University of Kansas, Lawrence, USA. hefferen@ku.edu
authors.forename: J J
authors.initials: JJ
authors.lastname: Hefferren
authors.forename: B
authors.initials: B
authors.lastname: Schemehorn
authors.forename: A
authors.initials: A
authors.lastname: Storeck
authors.forename: M
authors.initials: M
authors.lastname: Lerch
authors.forename: N
authors.initials: N
authors.lastname: Li
mesh_terms: D019985:Benchmarking; D002131:Calcium Pyrophosphate / Q000737:chemistry; D006801:Humans; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D014100:Toothpastes / Q000737:chemistry*
chemical_list: D014100:Toothpastes; D012822:Silicon Dioxide; D002131:Calcium Pyrophosphate