title: Effect of surface treatment on fatigue life of postceramic soldered joints.
abstract: OBJECTIVE
  This research investigated the effect of surface treatment on the fatigue life of metal-ceramic postsoldering.
  
  
  METHODS
  Twenty cylindric specimens were cast in a metal-ceramic alloy. All specimens received appropriate heat treatment simulating ceramic application, although no porcelain was applied. Each specimen was cut in half to form two half specimens. The 40 half specimens were randomly assigned to one of the four treatment groups, which differed in the type of surface treatment performed on one end of each half specimen (joint surface) prior to soldering: (1) aluminous oxide pink stone; (2) 50-micron aluminum oxide sandblasting; (3) brown rubber point; and (4) gray silicone wheel followed by pink silicone wheel. All surface treatments were performed for 30 seconds. The half specimens were then steam cleaned, aligned, indexed, and oven soldered with #650 postceramic solder. The soldering of two half specimens formed a complete test specimen, and a total of 20 postceramic soldered specimens were prepared. Following soldering, a 241.1 MPa fatigue stress was applied to each solder joint during specimen testing. The test variable was the number of stress cycles required to fail each specimen.
  
  
  RESULTS
  All specimens failed adhesively at the joint interface between the solder and parent metal. There were significant differences in the number of stress cycles to failure between groups 1 and 2, groups 1 and 4, and between groups 2 and 3.
  
  
  CONCLUSIONS
  The load cycle to failure for postceramic soldered joints was affected by the metal surface treatment.
authors.affiliation: Department of Prosthodontics, Box 357452, University of Washington, Seattle, Washington 98195-7452, USA. drrpress@u.washington.edu
authors.forename: R J
authors.initials: RJ
authors.lastname: Press
authors.forename: K
authors.initials: K
authors.lastname: Phillips
authors.forename: J
authors.initials: J
authors.lastname: Nicholls
authors.forename: T
authors.initials: T
authors.lastname: Butson
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D002516:Ceramics / Q000737:chemistry*; D003775:Dental Polishing; D012994:Dental Soldering; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D016876:Metal Ceramic Alloys / Q000737:chemistry*; D012408:Rubber / Q000737:chemistry; D012828:Silicones / Q000737:chemistry; D018709:Statistics, Nonparametric; D013227:Steam; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors
chemical_list: D016876:Metal Ceramic Alloys; D012828:Silicones; D013227:Steam; D012408:Rubber; D000537:Aluminum Oxide