The biocompatibility of two implantable materials, zirconia and alumina ceramics, was investigated in vitro using human osteoblast cell cultures. The viability of osteoblast cells with the materials was evaluated by the methylthiazole sulfate test that revealed an absence of any cytostatic or cytotoxic effect. Cell proliferation kinetic and total protein synthesis in osteoblasts with zirconia o...

PURPOSE The purpose of this study was to evaluate the effect of nano-structured alumina surface coating on shear bond strength between Y-TZP ceramic and various dual-cured resin cements. MATERIALS AND METHODS A total of 90 disk-shaped zirconia specimens (HASS CO., Gangneung, Korea) were divided into three groups by surface treatment method: (1) airborne particle abrasion, (2) tribochemicalsil...

Mullite (3Al2O3.2SiO2) and 10 mol% silica added zirconia (10 SiO2 - 90 ZrO2) ceramic powders were synthesized by conventional processing route. The mixtures prepared mechanical alloying method using ball mill in acetone environment. To synthesize mullite, Al2O3 mixture was with stoichiometric proportions fired it the air at 1600 oC for 3 h. And composites 1300 2 Thus, mullite composite phases o...

Polished plane-parallel sections (1 mm in thickness) of fused mullite (2Al 2 O 3 · 1SiO 2) were exposed to a slowly flowing (≈ 100 ml/min) water vapor containing atmosphere (H 2 O/O 2 = 20/80) at a temperature of 1670 °C for 1.5, 3, 6 and 12h, respectively. The water vapor experiments on fused mullite were carried out together with experiments on mullite single crystals reported earlier [1]. Al...

Ceramic composites based on alumina and zirconia have found a wide field of application in the present century orthopedic joint replacements, their use dentistry is spreading. The development this class bioceramic was started 1980s, but first clinical applications total hip replacement were introduced market only early 2000s. Since then, several composite systems replacements. These materials a...

Thin compressive layers within a laminar ceramic arrest large cracks (surface and internal) and produce a threshold strength. This phenomenon increases the damage tolerance of ceramics and will allow engineers to design reliable ceramic components for structural applications. The stress intensity factor derived for a crack sandwiched between two compressive layers suggests that the threshold st...

Three different alumina sources (boehmite, aluminium nitrate and α-alumina particles) 12Ce-TZP powder containing 1 wt% lanthanum oxide were used to prepare 12Ce-TZP-based alumina-toughened-zirconia (ATZ) composites. The obtained ATZs had similar density phase composition, whereas the microstructures significantly different. Alumina-particle addition gave rise a typical ATZ microstructure consis...

Zirconia-toughened alumina (ZTA) is of growing importance in a wide variety of fields exemplified by ZTA prosthetic implants. Unfortunately, ZTA composites are generally difficult to process because of the need to preserve the tetragonal zirconia phase in the final dense ceramic, coincident with the need to fully densify the a-Al2O3 component. We report here that liquid-feed flame spray pyrolys...

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...

1. Introduction Porous solids with bimodal pore structures are widely used as catalyst supports. Examples are formed bodies, such as tablets, beads, extrudates, and monoliths, of molecular sieves, silica and alumina. The formed bodies are prepared usually by compacting fine micro-or mesoporous particles [1]. As a result, macropores are formed between the agglomerated particles. Recently, cataly...