title: [Interface bond and compatibility between Mark II machining ceramic and vita VM9 veneering porcelain].
abstract: OBJECTIVE
  To investigate the interface bond and thermal compatibility between Mark II machining ceramic and Vita VM9 veneering porcelain.
  
  
  METHODS
  A bar shaped specimen (30 mm x 15 mm x 1 mm in size) of Mark II block was prepared, with 0.5 mm-deep notch (vertical to the long axis of specimen) at the middle of the bottom surface. The upper surface was veneered with 0.3 mm VM9 dentin base porcelain. Then the specimen was fractured from the notching site and the fracture surface was examined under scanning electron microscope (SEM) and electron microprobe analyzer (EMPA) with electron beam of 1 microm in diameter. Another ten specimens (30 mm x 15 mm x 1.5 mm in size) were fabricated and the temperature of thermal shock resistance were tested.
  
  
  RESULTS
  SEM observation showed tight bond between these two materials and EMPA results showed penetration of Al element from Mark II block into veneering porcelain and Ca element from veneering porcelain into Mark II block occurred after sintering baking. The average temperature of thermal shock resistance for specimens in this study was (194.0+/-10.3) degrees C. Cracks were mainly distributed in veneering porcelain.
  
  
  CONCLUSIONS
  Chemical bond exists between the Mark II machining ceramic and Vita VM9 veneering porcelain, and there is good thermal compatibility between them.
authors.affiliation: Dept. of Prosthodontics, Dalian Stomatology Hospital, Dalian 116021, China.
authors.forename: Tian-Shuang
authors.initials: TS
authors.lastname: Liu
authors.forename: Zhen-Chun
authors.initials: ZC
authors.lastname: Li
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Chen
mesh_terms: D002516:Ceramics; D003722:Dental Alloys; D003776:Dental Porcelain; D003799:Dental Stress Analysis; D003801:Dental Veneers; D008422:Materials Testing; D033081:Shear Strength; D015040:Zirconium
chemical_list: D003722:Dental Alloys; D003776:Dental Porcelain; C047040:Vita VMK 68; D015040:Zirconium