title: Effects of core characters and veneering technique on biaxial flexural strength in porcelain fused to metal and porcelain veneered zirconia.
abstract: OBJECTIVE
  The purpose of this study was to assess the impact of the core materials, thickness and fabrication methods of veneering porcelain on prosthesis fracture in the porcelain fused to metal and the porcelain veneered zirconia.
  
  
  METHODS
  Forty nickel-chrome alloy cores and 40 zirconia cores were made. Half of each core group was 0.5 mm-in thickness and the other half was 1.0 mm-in thickness. Thus, there were four groups with 20 cores/group. Each group was divided into two subgroups with two different veneering methods (conventional powder/liquid layering technique and the heat-pressing technique). Tensile strength was measured using the biaxial flexural strength test based on the ISO standard 6872:2008 and Weibull analysis was conducted. Factors influencing fracture strength were analyzed through three-way ANOVA (α≤.05) and the influence of core thickness and veneering method in each core materials was assessed using two-way ANOVA (α≤.05).
  
  
  RESULTS
  The biaxial flexural strength test showed that the fabrication method of veneering porcelain has the largest impact on the fracture strength followed by the core thickness and the core material. In the metal groups, both the core thickness and the fabrication method of the veneering porcelain significantly influenced on the fracture strength, while only the fabrication method affected the fracture strength in the zirconia groups.
  
  
  CONCLUSIONS
  The fabrication method is more influential to the strength of a prosthesis compared to the core character determined by material and thickness of the core.
authors.affiliation: Department of Prosthodontics, School of Dentistry and Institute of Oral Bio-Science, Chonbuk National University, Jeonju, Republic of Korea.
authors.forename: Ju-Won
authors.initials: JW
authors.lastname: Oh
authors.affiliation: Department of Prosthodontics, School of Dentistry and Institute of Oral Bio-Science, Chonbuk National University, Jeonju, Republic of Korea. ; Biomedical Research Institute, Chonbuk National University Hospital, Jeonju, Republic of Korea.
authors.forename: Kwang-Yeob
authors.initials: KY
authors.lastname: Song
authors.affiliation: Department of Prosthodontics, School of Dentistry and Institute of Oral Bio-Science, Chonbuk National University, Jeonju, Republic of Korea. ; Biomedical Research Institute, Chonbuk National University Hospital, Jeonju, Republic of Korea.
authors.forename: Seung-Geun
authors.initials: SG
authors.lastname: Ahn
authors.affiliation: Department of Prosthodontics, School of Dentistry and Institute of Oral Bio-Science, Chonbuk National University, Jeonju, Republic of Korea. ; Biomedical Research Institute, Chonbuk National University Hospital, Jeonju, Republic of Korea.
authors.forename: Ju-Mi
authors.initials: JM
authors.lastname: Park
authors.affiliation: Department Dental Biomaterials, Institute of Oral Bio-science, School of Dentistry, Chonbuk National University, Jeonju, Republic of Korea.
authors.forename: Min-Ho
authors.initials: MH
authors.lastname: Lee
authors.affiliation: Department of Prosthodontics, School of Dentistry and Institute of Oral Bio-Science, Chonbuk National University, Jeonju, Republic of Korea. ; Biomedical Research Institute, Chonbuk National University Hospital, Jeonju, Republic of Korea.
authors.forename: Jae-Min
authors.initials: JM
authors.lastname: Seo
keywords: Dental porcelain; Metal ceramic; Pressed ceramic; Tensile strength; Zirconia