title: Effect of posterior crown margin placement on gingival health.
abstract: BACKGROUND
  The clinical impact of posterior crown margin placement on gingival health has not been thoroughly quantified.
  
  
  OBJECTIVE
  This study evaluated the effect of posterior crown margin placement with multivariate analysis.
  
  
  METHODS
  Ten general dentists reviewed 240 patients with 480 metal-ceramic crowns in a prospective clinical trial. The alloy was randomly selected from 2 high gold, 1 low gold, and 1 palladium alloy. Variables were the alloy used, oral hygiene index score before treatment, location of crown margins at baseline, and plaque index and sulcus bleeding index scores recorded for restored and control teeth after 1 year. The effect of crown margin placement on sulcular bleeding and plaque accumulation was analyzed with regression models (P<.05).
  
  
  RESULTS
  The probability of plaque at 1 year increased with increasing oral hygiene index score before treatment. The lingual surfaces demonstrated the highest probability of plaque. The risk of bleeding at intrasulcular posterior crown margins was approximately twice that at supragingival margins. Poor oral hygiene before treatment and plaque also were associated with sulcular bleeding. Facial sites exhibited a lower probability of sulcular bleeding than lingual surfaces. Type of alloy did not influence sulcular bleeding.
  
  
  CONCLUSIONS
  In this study, placement of crown margins was one of several parameters that affected gingival health.
authors.affiliation: Department of Prosthetic Dentistry, School of Dentistry, Technical University of Dresden, Dresden, Germany. reitmei@rcs.urz.tu-dresden.de
authors.forename: Bernd
authors.initials: B
authors.lastname: Reitemeier
authors.forename: Kristina
authors.initials: K
authors.lastname: Hänsel
authors.forename: Michael H
authors.initials: MH
authors.lastname: Walter
authors.forename: Christian
authors.initials: C
authors.lastname: Kastner
authors.forename: Helge
authors.initials: H
authors.lastname: Toutenburg
mesh_terms: D000328:Adult; D001641:Bicuspid; D003442:Crowns / Q000009:adverse effects; D003773:Dental Plaque / Q000209:etiology; D003774:Dental Plaque Index; D005260:Female; D005891:Gingivitis / Q000209:etiology*; D006801:Humans; D008297:Male; D016876:Metal Ceramic Alloys / Q000737:chemistry; D008875:Middle Aged; D008963:Molar; D015999:Multivariate Analysis; D016017:Odds Ratio; D009911:Oral Hygiene Index; D010512:Periodontal Index; D011446:Prospective Studies; D017755:Prosthesis Fitting; D012044:Regression Analysis
chemical_list: D016876:Metal Ceramic Alloys