title: A comparison of the marginal adaptation of cathode-arc vapor-deposited titanium and cast base metal copings.
abstract: BACKGROUND
  A new fabrication process where a titanium coping, with a gold colored titanium nitride outer layer, can be reliably fused to porcelain; however, the marginal adaptation characteristics are undetermined.
  
  
  OBJECTIVE
  The purpose of the study was to compare the clinically acceptable marginal adaptation (CAMA - defined as a marginal gap mean of ≤ 60 μm) rates of cathode-arc vapor-deposited titanium and cast base metal copings to determine whether the titanium copings would produce a higher CAMA rate than the cast base metal copings.
  
  
  METHODS
  Thirty-seven cathode-arc vapor-deposited titanium copings and 40 cast base metal copings were evaluated using an optical microscope. Fifty vertical marginal gap measurements were made of each coping, and the mean of these measurements was used to form the gap score. A 1-tailed t test was used to compare the CAMA rates, and the Satterthwaite t-score was used to analyze the consistency of the coping adaptation (α =.05).
  
  
  RESULTS
  CAMA was achieved by 24 of the 37 (64.86%) titanium copings compared to 19 of the 40 (47.50%) base metal copings. A 1-tailed t test produced a Z-score of 1.533 (1-tailed P=.063), which allowed acceptance of the study hypothesis with only a modest risk of a Type I error.
  
  
  CONCLUSIONS
  Cathode-arc vapor-deposited titanium copings exhibited a higher rate of CAMA compared to base metal copings.
authors.affiliation: Private Practice, Newport Coast Oral Facial Institute, Newport Beach, Calif., USA. jcwu@ncofi.org
authors.forename: Jean C
authors.initials: JC
authors.lastname: Wu
authors.forename: Li-Chung
authors.initials: LC
authors.lastname: Lai
authors.forename: Cherilyn G
authors.initials: CG
authors.lastname: Sheets
authors.forename: James
authors.initials: J
authors.lastname: Earthman
authors.forename: Robert
authors.initials: R
authors.lastname: Newcomb
mesh_terms: D001641:Bicuspid; D002858:Chromium Alloys; D003442:Crowns; D018772:Dental Marginal Adaptation; D017267:Dental Prosthesis Design; D006801:Humans; D016876:Metal Ceramic Alloys; D009532:Nickel; D014025:Titanium; D014835:Volatilization
chemical_list: D002858:Chromium Alloys; D016876:Metal Ceramic Alloys; C041500:titanium nitride; D009532:Nickel; D014025:Titanium