Microstructural evidence of beryllium in commercial dental Ni-Cr alloys

Abstract

The focus of this work was to determine microstructural features in commercial Ni-Cr alloys which could be used to identify indirectly the presence of beryllium. Thus, eight commercial alloys were characterized by chemical analysis, thermal analysis, X-ray diffraction (XRD), scanning electron microscopy -back-scattered electron images (SEM/BSE), energy-dispersive spectroscopy (EDS). The results indicate that the presence of beryllium can be inferred from microstructural analysis via XRD and SEM/BSE. The X-ray diffractograms of the beryllium-containing alloys showed clearly the existence of the NiBe intermetallic phase. SEM/BSE images of these alloys show a very characteristic eutectic microstructure which also indicates the presence of this element. These characteristics are not observed in the beryllium-free alloys.

Metal-ceramic bond strength between a feldspathic porcelain and a Co-Cr alloy fabricated with Direct Metal Laser Sintering technique

“…In particular, Co-Cr base alloys are a reliable alternative since Ni has been implicated in allergic reactions of patients. 1 2 3 4 5 6 The excellent mechanical properties such as high Modulus of Elasticity, and the high corrosion resistance of Co-Cr alloys, in combination with their significantly low cost, are factors that make these alloys the first choice for dental metal-ceramic applications. 3 7 8 9 …”

Hysteretic Behavior of Twin Boundary Peak Due to Precipitation in Co-Ni-Cr alloy

“…However, some commercial Ni-Cr alloy dental prosthesis include beryllium in their composition to improve the castability and the interaction with dental ceramics [3][4][5] . Even if the investigated alloy is used with satisfaction since several years, the origin of its outstanding mechanical properties is still poorly understood, as well as the role of small alloying elements additions on mechanical properties.…”

Effect of Bonding Agent on Metal‐Ceramic Bond Strength between Co‐Cr Fabricated with Selective Laser Melting and Dental Feldspathic Porcelain

“…Alloy‐ceramic joint systems are very popular in fixed dental prosthetic restorations because they reliably maintain a high mechanical strength in a regime of continuous change (in intensity and direction) as far as chewing forces are concerned, as well as pronounced biocompatibility, very good esthetics, and low cost . Nickel‐chromium (Ni‐Cr), cobalt‐chromium (Co‐Cr), and titanium (Ti) alloys are widely used in dental metal‐ceramic applications because they satisfy the above criteria . Nonetheless, Co‐Cr alloys are the most popular among them, as they are less expensive than Ti alloys, and because several studies have reported on the allergic effects of Ni .…”

“…Nickel‐chromium (Ni‐Cr), cobalt‐chromium (Co‐Cr), and titanium (Ti) alloys are widely used in dental metal‐ceramic applications because they satisfy the above criteria . Nonetheless, Co‐Cr alloys are the most popular among them, as they are less expensive than Ti alloys, and because several studies have reported on the allergic effects of Ni . Co‐Cr alloys possess high strength, low density, good thermal resistance, biocompatibility, and remarkable corrosion resistance in the oral cavity …”

“…Nonetheless, Co‐Cr alloys are the most popular among them, as they are less expensive than Ti alloys, and because several studies have reported on the allergic effects of Ni . Co‐Cr alloys possess high strength, low density, good thermal resistance, biocompatibility, and remarkable corrosion resistance in the oral cavity …”