title: Studies on the effect of polyvinyl pyrrolidone on the activity of chlorhexidine mouthrinses: plaque and stain.
abstract: OBJECTIVE
  Polyvinyl pyrrolidone (PVP) was shown in vitro to reduce chlorhexidine induced, dietary staining without affecting the uptake of the antiseptic to the test substrate. The aim of these studies in vivo was to determine whether PVP affected plaque and dietary staining by a low concentration chlorhexidine rinse.
  
  
  METHODS
  The plaque and stain studies used a double blind, randomised 6, treatment crossover design involving healthy subjects with a high standard of oral hygiene and gingival health. The rinse formulations under test were: (A) aqueous alcohol (placebo control), (B) 0.03% chlorhexidine, (C) 0.06% chlorhexidine, (D) 0.06% chlorhexidine+1.2% PVP, (E) 0.06% chlorhexidine+5% PVP, (F) 0.06% chlorhexidine+10% PVP. In the plaque study, on day 1 of each period, subjects were rendered plaque free and then rinsed with 15 ml of the test rinse for 60 s. No further tooth cleaning was performed and subjects returned 24 h later for plaque scoring by area. In the stain study, on day 1 of each period, the tongue and teeth of each subject were rendered stain free. Subjects then rinsed under supervision for 60 s with 15 ml of the allocated rinse 8 x a day between 09:00 h and 17:00 h for 3 days. Immediately after each rinse with the test formulation, subjects rinsed for 120 s with 15 ml of warm black tea. Subjects were requested to also drink at least 5 cups of tea or coffee per day. On day 4, stain was scored by area and intensity from designated teeth and dorsum of the tongue. Washout periods were at least 7 days in both studies.
  
  
  RESULTS
  Plaque areas were greatest with placebo and least with 0.06% chlorhexidine. Plaque scores increased with increasing concentrations of PVP in the 0.06% chlorhexidine rinse and were significantly higher than 0.06% chlorhexidine without PVP rinse. Tooth stain areas were comparable for placebo, 0.03% and 0.06% chlorhexidine rinses, but significantly reduced with the PVP/chlorhexidine rinses compared to the 0.06% chlorhexidine rinse. Tooth stain intensity was significantly increased with 0.06% chlorhexidine rinses compared to placebo and chlorhexidine/PVP rinses. Tongue stain area and intensity were significantly reduced with 5% and 10% PVP/chlorhexidine rinses compared to 0.06% chlorhexidine rinse.
  
  
  CONCLUSIONS
  PVP, at the concentrations tested, reduced the stain propensity of a 0.06% chlorhexidine rinse but at the expense of some loss of plaque inhibition.
authors.affiliation: Division of Restorative Dentistry, Dental School, Bristol, UK.
authors.forename: N
authors.initials: N
authors.lastname: Claydon
authors.forename: M
authors.initials: M
authors.lastname: Addy
authors.forename: R
authors.initials: R
authors.lastname: Jackson
authors.forename: S
authors.initials: S
authors.lastname: Smith
authors.forename: R G
authors.initials: RG
authors.lastname: Newcombe
mesh_terms: D000293:Adolescent; D000328:Adult; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D002710:Chlorhexidine / Q000008:administration & dosage / Q000627:therapeutic use*; D003069:Coffee / Q000009:adverse effects; D003116:Color; D018592:Cross-Over Studies; D003773:Dental Plaque / Q000517:prevention & control*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009067:Mouthwashes / Q000627:therapeutic use*; D010592:Pharmaceutic Aids / Q000627:therapeutic use*; D010919:Placebos; D011205:Povidone / Q000008:administration & dosage / Q000627:therapeutic use*; D018709:Statistics, Nonparametric; D013662:Tea / Q000009:adverse effects; D014059:Tongue / Q000187:drug effects / Q000473:pathology; D014075:Tooth Discoloration / Q000139:chemically induced* / Q000517:prevention & control
chemical_list: D000891:Anti-Infective Agents, Local; D003069:Coffee; D009067:Mouthwashes; D010592:Pharmaceutic Aids; D010919:Placebos; D013662:Tea; D011205:Povidone; D002710:Chlorhexidine