OBJECTIVES To comparatively assess the micro shear bond strength (MSBS) of dentin bonded surface pre-treated zirconia ceramics. MATERIALS AND METHODS Zirconia blocks were sectioned into 50 cubical blocks. The blocks were further categorized into five groups (n = 10 each). Group I: No treatment was performed on zirconia samples; Group II: The zirconia samples were sand-blasted; Group III: Grou...

OBJECTIVE The objective of this study was to compare microhardness of resin cements under different thicknesses of zirconia and the light transmittance of zirconia as a function of thickness. STUDY DESIGN A total of 126 disc-shaped specimens (2 mm in height and 5 mm in diameter) were prepared from dual-cured resin cements (RelyX Unicem, Panavia F and Clearfil SA cement). Photoactivation was p...

BACKGROUND One of the disadvantages of the zirconia implants is the lack of elasticity, which is increased with the use of ceramic or zirconia crowns. The consequences that could result from this lack of elasticity have led to the search for new materials with improved mechanical properties. CASE PRESENTATION A patient who is a 45-year-old woman, non-smoker and has no medical record of intere...

This study was conducted to enhance the tensile bond strengths of resin cements to zirconia ceramics. Fifty-six zirconia ceramic specimens (Cercon Base) and twenty-eight silica-based ceramic specimens (GN-1, GN-1 Ceramic Block) were air-abraded using alumina. Thereafter, the zirconia ceramic specimens were divided into two subgroups of 28 each according to the surface pretreatment; no pretreatm...

Zirconia is one of the important ceramic which is used as a biomaterial that has a bright future because of its high mechanical strength and fracture toughness and has unique a characteristic called transformation toughening, which can give it higher strength and toughness compared with other ceramics. This paper reviews the synthesis methods and applications of Zirconia. It exhibits three well...

ESTHETIC REHABILITATION THROUGH CAD/CAM TECHNOLOGY-CASE REPORT (Abstract): With the progress of dental materials and techniques, CAD/CAM system curren tly allows the manufacture of high precision prosthetic restorations. Zirconia is an ideal base for porcelain because the bonding process between the zirconia and the porcelain is stronger than it is with porcelain and metal. This means that the ...

Zirconia doped Hydroxyapatite (HAP) nanocrystals [Ca10(PO4)6-x(ZrO2)x(OH)2]; (0 ≤ x ≤ 1 step 0.2) were synthesized using simple low cost facile method. The crystalline phases were examined by X-ray diffraction (XRD). The crystallinity percentage decreased with increasing zirconia content for the as-synthesized samples. The existence of zirconia as secondary phase on the grain boundaries; as obs...

The thermoluminescence (TL) after excitation by UV or X-rays radiation of doped α-alumina powders is investigated. In the case of zirconia, the alumina-zirconia composites present five of the characteristic peaks of zirconia at –170, –145, –90, 0 and 95°C. After a thermal treatment of mixed oxides, a new peak is observed at –35°C in TL. This peak reveals the presence of stabilized tetragonal zi...

The failure events of Prozyr femoral heads in 2001-2002 have opened a strong, controversial issue on the future of zirconia as a biomaterial. The aim of this paper is to review and analyze the current knowledge on ageing process and on its effect on the long term performance of implants in order to distinguish between scientific facts and speculation. Current state of the art shows the strong v...

F. Tehovnik, J. Burja, B. Arh, Institute of metals and technology, Ljubljana, Slovenia, M. Knap, University of Ljubljana, Faculty of Natural Sciences and Engineering, Ljubljana, Slovenia Nozzle clogging is a common problem in the production of continuously cast Al-killed steels. Clogging occurs when there are solid inclusions in molten steel at casting temperatures. SENs (Submerged entry nozzle...