Effect of firing cycle and surface finishing on the sag resistance of long-span metal ceramic framework using base metal alloys—an in vitro study

Abstract

(12)60016-1 sag-related deflection was less in Co-Cr alloys as compared with the Ni-Cr alloys, still Ni-Cr alloys in fixed dental prostheses frameworks are used due to their desirable physical and chemical properties. MJAFI 2012;68:145-150

Effect of ice-quenching on the change in hardness of a Pd-Au-Zn alloy during porcelain firing simulation

“…The metal substructure needs to undergo an appropriate adjustment, such as trimming for adaptation to the master model after casting. Subsequently, degassing is performed at approximately 1,000°C, where sag and thermal distortion of the metal substructure can take place easily [4][5][6] . If this occurs, the metal substructure needs to be readjusted after degassing.…”

“…Subsequently, degassing, which is the first step in the firing process for bonding porcelain, is performed at the highest temperature. Therefore, sag and thermal distortion of the metal substructure can occur easily [4][5][6] . If this occurs, the metal substructure needs to be readjusted after degassing.…”

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 .…”

“…In this case, this layer is termed bonding agent, and aims at improving the chemical affinity between dissimilar materials . Appropriate matching of mechanical properties refers to the modulus of elasticity (Young modulus), while the matching of thermal properties is measured by the values of the coefficient of linear thermal expansion (CTE) . Regarding the CTE, it has been shown that the alloy should preferably have a slightly higher CTE in order to reduce undesirable tensile stresses on the porcelain, since ceramics (such as porcelain) exhibit high compressive strength but poor tensile strength .…”