title: Comparison of the metal-ceramic bond after recasting and after laser sintering.
abstract: BACKGROUND
  Failure of the bond between metal and ceramic is common with metal ceramic prostheses.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to investigate how recasting affects the metal-ceramic bond strength for 1 base metal and 1 noble alloy compared with laser-sintered Co-Cr alloy by using a procedure based on ANSI/ADA Specification No. 38.
  
  
  METHODS
  One laser-sintered (Co-Cr) and 2 metal (Co-Cr, Pd-Ag) alloys were used. Metal strips (25 × 3 × 0.5 mm) were obtained with 2 different methods: torch melting and laser sintering. Twelve alloy specimens were processed for each group. Vita VM13 porcelain layers (8 × 3 × 1.1 mm) were fabricated at the centers of the metal frameworks. Specimens containing 100% fresh alloy were used in the first casting group (control). Metal ceramic specimens were prepared for each alloy, and no new metal was added to the second and third castings. The findings were statistically analyzed and compared with a 2-way analysis of variance (ANOVA).
  
  
  RESULTS
  The second casting of the noble alloy-ceramic specimen had the highest mean metal-ceramic bond strength in flexure. No significant differences were found between the laser-sintered Co-Cr and the Pd-Ag metal ceramic specimens after the first and third castings.
  
  
  CONCLUSIONS
  All groups had adequate porcelain bond strength, except C2 (second casting of Co-Cr alloy) and C3 (third casting of Co-Cr alloy). Co-Cr alloy fabricated with new laser-sintering techniques is a promising alternative for metal ceramic restorations. Further research is needed before its use can be advocated in the dental laboratory.
authors: Research Assistant, Department of Prosthodontics, Faculty of Dentistry, Atatürk University, Erzurum, Turkey.
authors: Esra
authors: E
authors: Kul
authors: Professor, Department of Prosthodontics, Atatürk University, Faculty of Dentistry, Atatürk University, Erzurum, Turkey.
authors: Lütfü Ihsan
authors: LI
authors: Aladag
authors: Professor, Department of Prosthodontics, Atatürk University, Faculty of Dentistry, Atatürk University, Erzurum, Turkey. Electronic address: zyesilz@hotmail.com.
authors: Zeynep Yesil
authors: ZY
authors: Duymus
mesh_terms: D002858:Chromium Alloys / Q000737:chemistry; D001840:Dental Bonding; D003735:Dental Casting Technique; D003776:Dental Porcelain / Q000737:chemistry*; D006047:Gold Alloys / Q000737:chemistry; D006358:Hot Temperature; D006801:Humans; D007834:Lasers; D008422:Materials Testing; D016876:Metal Ceramic Alloys / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry; D018583:Pliability; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D002858:Chromium Alloys; D006047:Gold Alloys; D016876:Metal Ceramic Alloys; D003776:Dental Porcelain; D010165:Palladium