XRD2 micro-diffraction analysis of the interface between Y-TZP and veneering porcelain: Role of application methods

• Published in: Dental materials Vol. 26; no. 6; pp. 545 - 552
• Main Authors: Tholey, Michael J, Berthold, Christoph, Swain, Michael V, Thiel, Norbert
• Format: Journal Article
• Language: English
• Published: England 01.06.2010
• Subjects: Advanced Basic Science; Aluminum Oxide; Computer-Aided Design; Crystal structure; Crystallization; Dental Bonding; Dental materials; Dental Porcelain - chemistry; Dental Veneers; Dentistry; Hot Temperature; Humans; Materials Testing; Microscopy, Electron, Scanning; Phase Transition; Porcelain; Restoration; Stability; Surface Properties; Transformations; Veneering; X-Ray Diffraction - instrumentation; X-Ray Diffraction - methods; Yttrium; Yttrium - chemistry; Zirconium - chemistry; Zirconium dioxide; Zirconia; X-ray diffraction; Veneering material; Y-TZP; All-ceramic; Interface
• ISSN: 0109-5641; 1879-0097
• DOI: 10.1016/j.dental.2010.02.002

Abstract Objectives The metastability of the tetragonal crystal structure of yttria partial stabilized zirconia polycrystalline (Y-TZP) ceramics is a basis of concern for dental restorations. Reactions between the porcelain and the Y-TZP framework may result in a reduction of the stability of the zirconia and interface bonding caused by a transformation from tetragonal to monoclinic crystalline structure during veneering. Methods XRD2 micro-diffraction measurements were carried out on tapered veneered cross-sections of the interface area to generate locally resolved information of the phase content in this region. To get a high intensity X-ray beam for short measurement times a focussing polycapillary with a spot size of app. 50 μm was used to evaluate the porcelain zirconia interface. Results Under almost all conditions the phase composition of zirconia grains at the interface revealed both the monoclinic and tetragonal structure. These observations indicate that destabilization of the tetragonal phase of zirconia occurs at the interface during veneering with porcelain. Significance These results and their relevance to the long-term stability of the interface adhesion between zirconia and veneering porcelain as well as the tetragonal to monoclinic crystal transformations at the interface are discussed.