title: The effect of unstimulated and stimulated whole saliva on extrinsic staining in vitro--a developmental method.
abstract: OBJECTIVE
  To detect any differences in the propensity of unstimulated and stimulated, individual whole saliva to cause in vitro staining by chlorhexidine and tea.
  
  
  METHODS
  Unstimulated and stimulated human saliva was collected on a daily basis and used to coat optically clear acrylic specimens. Specimens were subjected to an established chlorhexidine/tea staining model in vitro shown to correlate well with in vivo staining, and cycles repeated until an optical density of <2 was reached.
  
  
  RESULTS
  Stain development increased incrementally with increasing cycles. Overall differences in chlorhexidine/tea staining were noted both between subjects and between unstimulated and stimulated saliva used. Mean staining for the subject group, at each cycle was always higher with unstimulated saliva compared to stimulated saliva and differences reached statistical significance at cycles 2-5.
  
  
  CONCLUSIONS
  In vitro stain formation using unstimulated saliva from different individuals occurred at a faster rate and to a greater extent than when stimulated saliva from the same subjects was used, presumably reflecting differences in composition. Understanding the nature of these differences could provide fundamental information on the very poorly understood process of tooth staining.
authors.affiliation: Division of Restorative Dentistry, Bristol Dental School, Lower Maudlin Street, Bristol BS1 2LY, UK. sarah.sheen@bristol.ac.uk
authors.forename: Sarah
authors.initials: S
authors.lastname: Sheen
authors.forename: Nicholas
authors.initials: N
authors.lastname: Banfield
authors.forename: Martin
authors.initials: M
authors.lastname: Addy
mesh_terms: D000891:Anti-Infective Agents, Local / Q000009:adverse effects; D002710:Chlorhexidine / Q000009:adverse effects; D003741:Dental Deposits / Q000737:chemistry; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D012463:Saliva / Q000737:chemistry* / Q000378:metabolism; D013662:Tea / Q000009:adverse effects; D014075:Tooth Discoloration / Q000139:chemically induced*
chemical_list: D000891:Anti-Infective Agents, Local; D013662:Tea; D002710:Chlorhexidine