title: An in vivo study of the impact of different emergence profiles of procera titanium crowns on quantity and quality of plaque.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effect of crowns with different emergence profiles on marginal plaque formation.
  
  
  METHODS
  Seven crown preparations were performed on premolar teeth in six patients. Four titanium crowns for each tooth--with different marginal emergence angles--were manufactured according to the Procera technique. The three experimental crowns and the final permanent tooth were cemented with phosphate permanent cement. Plaque samples were collected from the marginal area after 1 week with normal oral hygiene, and again after refraining from oral hygiene for 2 days. The contralateral tooth served as a control. The quantity and quality of plaque were registered. The restoration was removed, the next crown version cemented, and the protocol repeated.
  
  
  RESULTS
  All experimental crowns, irrespective of emergence profile, showed a significantly lower (P = .01) plaque quantity than controls. No intraindividual differences were found regarding the accumulation of mutans streptococci at the different experimental emergence profiles. No differences in quality between experimental and control sides were found.
  
  
  CONCLUSIONS
  Within the limitations of this study, it was found that titanium crowns with emergence profiles of up to 40 degrees formed less plaque than healthy controls. There was no higher accumulation of mutans streptococci in relation to increasing emergence profiles.
authors.affiliation: Department of Prosthetic Dentistry/Dental Materials Science, Faculty of Odontology, Göteborg University, Box 450, SE 405 30 Göteborg, Sweden. sundh@odontologi.gu.se
authors.forename: Bo
authors.initials: B
authors.lastname: Sundh
authors.forename: Birgitta
authors.initials: B
authors.lastname: Köhler
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D015169:Colony Count, Microbial; D017076:Computer-Aided Design; D003442:Crowns; D018772:Dental Marginal Adaptation; D003773:Dental Plaque / Q000382:microbiology*; D003776:Dental Porcelain; D017267:Dental Prosthesis Design; D005260:Female; D006801:Humans; D008297:Male; D016876:Metal Ceramic Alloys; D008875:Middle Aged; D018709:Statistics, Nonparametric; D013295:Streptococcus mutans; D013499:Surface Properties; D014025:Titanium
chemical_list: D016876:Metal Ceramic Alloys; C077451:Procera; D003776:Dental Porcelain; D014025:Titanium