title: Root surface debridement and endotoxin removal.
abstract: OBJECTIVE
  This study assessed associations between the number of standardized scaling strokes and the reduction of endotoxin on the root surface.
  
  
  BACKGROUND
  Therapy of periodontally involved teeth attempts removal of accretions by scaling and root planing. The amount of mechanical therapy required to free the root surface from etiologic factors remains unknown.
  
  
  METHODS
  Twenty-four extracted human caries-free single rooted teeth with at least 5 mm attachment loss were used. A region of interest (ROI) which contained subgingival calculus was defined on the root surface of each tooth. Standardized force instrumentation was applied using a force-measuring curet. Fifty working strokes were applied to every ROI. Forces applied were recorded. The force recordings were converted from Millivolts into Newtons (N). After every unit of 5 strokes, presence of calculus was evaluated and scaling debris was collected. Endotoxin concentration was determined in the debris samples.
  
  
  RESULTS
  The endotoxin values for strokes 1-5 were statistically significantly greater than the values from all other stroke intervals. Complete calculus removal occurred after a mean of 9.3 strokes. The endotoxin concentration reached a minimal level with concentrations of 0.03-0.306 EU/ml after calculus removal was complete.
  
  
  CONCLUSIONS
  These findings suggest that completion of calculus removal coincides with endotoxin levels associated with clinically healthy teeth.
authors.affiliation: Department of Periodontology, Endodontology and Cariology, School of Dental Medicine, University of Basle, Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Cadosch
authors.forename: U
authors.initials: U
authors.lastname: Zimmermann
authors.forename: M
authors.initials: M
authors.lastname: Ruppert
authors.forename: J
authors.initials: J
authors.lastname: Guindy
authors.forename: D
authors.initials: D
authors.lastname: Case
authors.forename: U
authors.initials: U
authors.lastname: Zappa
mesh_terms: D002863:Chromogenic Compounds; D003728:Dental Calculus / Q000737:chemistry / Q000628:therapy; D012534:Dental Scaling / Q000295:instrumentation / Q000379:methods*; D004731:Endotoxins / Q000032:analysis*; D006801:Humans; D008033:Limulus Test; D016014:Linear Models; D017622:Periodontal Attachment Loss / Q000473:pathology; D010518:Periodontitis / Q000473:pathology; D016745:Root Planing / Q000295:instrumentation / Q000379:methods*; D013314:Stress, Mechanical; D013357:Subgingival Curettage / Q000295:instrumentation / Q000379:methods; D014092:Tooth Root / Q000473:pathology*
chemical_list: D002863:Chromogenic Compounds; D004731:Endotoxins