title: An intraindividual clinical comparison of two metal-ceramic systems: a 5-year prospective study.
abstract: OBJECTIVE
  Earlier studies on low-fusing ceramics have shown the occurrence of changes over time regarding surface and color. The present prospective study is an ongoing follow-up of an intraindividual comparison between two metal-ceramic systems, the Procera system (titanium copings veneered with a low-fusing ceramic) and noble-alloy copings veneered with a medium-fusing ceramic.
  
  
  METHODS
  Twenty-one crown pairs were fabricated for 18 patients. After 5 years, 18 crown pairs in 15 patients were available for comparison. The crowns were examined shortly after cementation (baseline), and after 1, 2, and 5 years. The crowns were rated according to the CDA system. Bleeding index and margin index were also evaluated.
  
  
  RESULTS
  Obvious changes regarding surface and color were noted for the titanium-ceramic crowns. The difference between the two types of crowns was statistically significant at 5 years (P = .004). The differences between the two systems regarding anatomic form, margin integrity, bleeding index, and margin index were small.
  
  
  CONCLUSIONS
  Within the limitations of this study, it is concluded that low-fusing ceramic-veneered titanium copings are inferior to medium-fusing ceramic-veneered conventional copings regarding surface and color of the ceramic. Therefore, conventional ceramic-veneered crowns seem to be preferable, at least in the anterior area, where the esthetic requirements are greater than in premolar and molar regions. Whether possible changes in the properties of low-fusing ceramics will reduce the differences between the two types of metal-ceramic crowns remains to be proven.
authors.affiliation: Department of Clinical Oral Physiology, Medical-Odontological Faculty, Umeå University, Sweden. susanna.marklund@odont.umu.se
authors.forename: Susanna
authors.initials: S
authors.lastname: Marklund
authors.forename: Bo
authors.initials: B
authors.lastname: Bergman
authors.forename: Sven-Olof
authors.initials: SO
authors.lastname: Hedlund
authors.forename: Hans
authors.initials: H
authors.lastname: Nilson
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003116:Color; D003442:Crowns; D003776:Dental Porcelain / Q000737:chemistry*; D017267:Dental Prosthesis Design; D003801:Dental Veneers; D005260:Female; D005500:Follow-Up Studies; D006047:Gold Alloys / Q000737:chemistry; D006801:Humans; D008297:Male; D016876:Metal Ceramic Alloys / Q000737:chemistry*; D008875:Middle Aged; D010512:Periodontal Index; D011446:Prospective Studies; D013223:Statistics as Topic; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry
chemical_list: D006047:Gold Alloys; D016876:Metal Ceramic Alloys; C077451:Procera; D003776:Dental Porcelain; D014025:Titanium