title: Microtensile bond strength of lithium disilicate to zirconia with the CAD-on technique.
abstract: OBJECTIVE
  Recently, a novel technique was introduced to combine lithium disilicate and zirconia into one restoration. The purpose of this study was to compare the microtensile bond strength of veneering ceramic to a zirconia core in two techniques: the e.max® CAD-on technique and the Press-on technique.
  
  
  METHODS
  Group A was prepared by veneering sintered zirconia blocks (e.max® ZirCAD) with lithium disilicate blocks (e.max® CAD) using the CAD-on technique according to manufacturer's instructions. Group B was prepared by taking sintered e.max® ZirCAD blocks and veneering them with fluorapatite glass-ceramic (e.max® ZirPress) using the Press-on technique according to manufacturer's instructions. Each block was loaded in a dynamic cyclic loading machine. The blocks were then sectioned into 1 × 1 mm(2) beams (n = 43) using a precision saw, thermocycled, and loaded in tension until failure on a universal testing machine. A mean and standard deviation were determined per group. Data were analyzed using an unpaired t-test (α = 0.05).
  
  
  RESULTS
  The mean microtensile bond strengths were 44.0 ± 13.8 MPa for the CAD-on technique and 14.9 ± 8.8 MPa for the Press-on technique. Significant differences were found between the two groups (p = 2.7E-19).
  
  
  CONCLUSIONS
  The CAD-on technique (lithium disilicate/zirconia) resulted in greater microtensile bond strength than the Press-on technique (fluorapatite glass-ceramic/zirconia).
authors: 10th Dental Squadron, US Air Force Academy, Colorado Springs, CO.
authors: James J
authors: JJ
authors: Renda
authors: Aaron B
authors: AB
authors: Harding
authors: Clifton W
authors: CW
authors: Bailey
authors: Villa L
authors: VL
authors: Guillory
authors: Kraig S
authors: KS
authors: Vandewalle
mesh_terms: D001031:Apatites; D002516:Ceramics / Q000737:chemistry; D003776:Dental Porcelain / Q000737:chemistry*; D017267:Dental Prosthesis Design / Q000379:methods*; D003799:Dental Stress Analysis; D003801:Dental Veneers; D008422:Materials Testing / Q000379:methods; D011476:Prosthodontics / Q000379:methods*; D013718:Tensile Strength; D015040:Zirconium / Q000737:chemistry*
chemical_list: D001031:Apatites; C493120:lithia disilicate; D003776:Dental Porcelain; C023506:Glass ceramics; D015040:Zirconium; C025105:fluorapatite; C028541:zirconium oxide
keywords: All-ceramic; CAD-on; Press-on; microtensile bond strength; zirconia framework