Characterizing the transformation near indents and cracks in clinically used dental yttria-stabilized zirconium oxide constructs.

Objectives: Tetragonal zirconia polycrystal (TZP) materials are widely used for full ceramic partial dentures, even though their mechanical properties might change during service. A key property for the durability of the constructs is thought to be an inhibition of crack propagation by phase transformation toughening. Because dental prosthesis are ground and polished for adjustment purposes, it is important to understand the effects of mechanical surface treatments, on localized transformation and around the propagating cracks.

Tetragonal and cubic zirconia multilayered ceramic constructs created by EPD.

The interest in electrophoretic deposition (EPD) for nanomaterials and ceramics production has widely increased due to the versatility of this technique to effectively combine different materials in unique shapes and structures. We successfully established an EPD layering process with submicrometer sized powders of Y-TZP with different mol percentages of yttrium oxide (3 and 8%) and produced multilayers of alternating tetragonal and cubic phases with a clearly defined interface. The rationale behind the design of these multilayer constructs was to optimize the properties of the final ceramic by combining the high mechanical toughness of the tetragonal phase of zirconia together with the high ionic conductivity of its cubic phase.

Novel soybean/gelatine-based bioactive and injectable hydroxyapatite foam: material properties and cell response.

Despite their known osteoconductivity, clinical use of calcium phosphate cements is limited both by their relatively slow rate of resorption and by rheological properties incompatible with injectability. Bone in-growth and material resorption have been improved by the development of porous calcium phosphate cements. However, injectable formulations have so far only been obtained through the addition of relatively toxic surfactants.

Self-hardening calcium deficient hydroxyapatite/gelatine foams for bone regeneration.

In this work gelatine was used as multifunctional additive to obtain injectable self-setting hydroxyapatite/gelatine composite foams for bone regeneration. The foaming and colloidal stabilization properties of gelatine are well known in food and pharmaceutical applications. Solid foams were obtained by foaming liquid gelatine solutions at 50 degrees C, followed by mixing them with a cement powder consisting of alpha tricalcium phosphate.

Foamed surfactant solution as a template for self-setting injectable hydroxyapatite scaffolds for bone regeneration.

The application of minimally invasive surgical techniques in the field of orthopaedic surgery has created a growing need for new injectable synthetic materials that can be used for bone grafting. In this work a novel fully synthetic injectable calcium phosphate foam was developed by mixing alpha-tricalcium phosphate (alpha-TCP) powder with a foamed polysorbate 80 solution. Polysorbate 80 is a non-ionic surfactant approved for parenteral applications.