Is titanium-zirconium alloy a better alternative to pure titanium for oral implant? Composition, mechanical properties, and microstructure analysis.

Introduction: Titanium (Ti) is widely accepted as a biomaterial for orthopaedic and dental implants, primarily due to its capacity to integrate directly into the bone and its superior corrosion resistance. It has been suggested that titanium-zirconium alloy (TiZr), with 13-17% of zirconium, has better mechanical properties than pure Ti, but there are very few published studies assessing the suitability of TiZr for high-load- bearing implants. This study aimed to compare the mechanical properties and microstructures of TiZr and commercially pure titanium (Ti).

Porcelain bonding to novel Co-Cr alloys: Influence of interfacial reactions on phase stability, plasticity and adhesion.

Objective: The objective of the present study was to determine the hardness and adhesion strength at the porcelain to alloy interface.

Methods: 15 bi-layer porcelain veneered Co-Cr specimens of each alloy group [cast, powder metallurgy (PM), CAD/CAM(CC)] were manufactured. 12 bi-layered specimens were tested using four-point bend strain energy release rate adhesion test.

Comparison of the microstructure and phase stability of as-cast, CAD/CAM and powder metallurgy manufactured Co-Cr dental alloys.

Objective: The objective of this study was to identify the different microstructures produced by CC, PM and as-cast techniques for Co-Cr alloys and their phase stability following porcelain firings.

Methods: Three bi-layer porcelain veneered Co-Cr specimens and one monolithic Co-Cr specimen of each alloy group [cast, powder metallurgy (PM), CAD/CAM (CC)] were manufactured and analyzed using electron backscatter diffraction (EBSD), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). Specimens were treated to incremental numbers of porcelain firings (control 0, 5, 15) with crystallographic data, grain size and chemical composition subsequently obtained and analyzed.

Influence of a tungsten metal conditioner on the adhesion and residual stress of porcelain bonded to cobalt-chromium alloy.

Statement Of Problem: Cobalt-chromium (CoCr) metal ceramic restorations are known to be more susceptible to cracking and interfacial failures. This is partially related to their high potential for oxidation compared with restorations made with high noble alloys. One approach that may improve their compatibility is the use of bonding agents.

Effect of autoclave induced low-temperature degradation on the adhesion energy between yttria-stabilized zirconia veneered with porcelain.

Objective: To investigate the effect of autoclave induced low-temperature degradation on the adhesion energy between yttria-stabilized zirconia veneered with porcelain.

Methods: The strain energy release rate using a four-point bending stable fracture test was evaluated for two different porcelains [leucite containing (VM9) and glass (Zirox) porcelain] veneered to zirconia. Prior to veneering the zirconia had been subjected to 0 (control), 1, 5, 10 and 20 autoclave cycles.

Bang! Month-scale eruption triggering at Santorini volcano.

The time lag between intrusion of fresh, hot magma and an ensuing eruption is of critical importance in both understanding the triggering and mitigating the consequences of volcanic eruptions. This work looks at material erupted during 1925-28 at the Nea Kameni volcanic center in Santorini, Greece, to determine this time scale. By exploiting Fe-Mg diffusion in olivine crystals, we constrained the intrusion-to-eruption time lag to between 3 and 10 weeks.

Morphological analyses of minute crystals by using stereo-photogrammetric scanning electron microscopy and electron back-scattered diffraction.

We present a new method for the morphological analyses of minute faceted crystals by combining stereo-photogrammetric analysis of scanning electron microscope images and electron back-scattered diffraction. Two scanning electron microscope images of the same crystal, recorded at different tilt angles of the specimen stage, are used to determine the orientations of crystal edges in a specimen-fixed coordinate system. The edge orientations are converted to the indices [uvw] in the crystal system using the crystal orientation determined by electron back-scattered diffraction analysis.