Abstract: A method for casting dental metals with a casting apparatus including a melting chamber in which there are located an arc electrode above and a crucible formed of an electrically conductive material positioned below the arc electrode, and a mold chamber divided from the melting chamber by a partition wall having a through-hole at a position below the crucible and housing a mold box receiving a mold provided with an extending open vent positioned below the through-hole, the melting chamber communicating hermetically with the mold chamber through the mold, which is characterized by positioning a dental metal ingot on the crucible, vacuumizing the melting and mold chambers, feeding a small amount of an inert gas into the melting chamber at such a pressure as to induce arc discharge all over the upper surface of the ingot, thereby melting the ingot placed on the crucible by arc discharge from the arc electrode, pouring the thus obtained molten metal into the mold through its inlet, and immediately feeding an addi

Abstract: A method for casting dental metals with a casting apparatus including a hermetically sealed casting chamber in which an arc electrode is located above, a crucible made of an electrically conductive material is positioned below the arc electrode, and a mold provided with a closed vent is disposed below the crucible, the method including by positioning a dental metal ingot on the crucible, evacuating the casting chamber to vacuum, feeding a small amount of an inert gas at such a pressure as to induce arc discharge all over the upper surface of the ingot, thereby melting the ingot placed on the crucible by arc discharge from the arc electrode, pouring the thus obtained molten metal into a mold through its inlet, and immediately feeding an additional amount of the inert gas into the casting chamber to increase its internal pressure to a level suitable for casting. Also the additional amount of the inert gas is rapidly fed into the casting chamber through a gas tank in the vicinity of the casting chamber.

Abstract: A dental amalgam alloy containing selenium includes one or two or more of powders of chemically synthesized copper selenides (CuSe, Cu.sub.2 Se), silver selenide (Ag.sub.2 Se), gold selenide (Au.sub.2 Se.sub.3), nickel selenide (NiSe), palladium selenides (PdSe, PdSe.sub.2), platinum selenides (PtSe.sub.2, PtSe.sub.3), zinc selenide (ZnSe), mercury selenide (HgSe), indium selenide (In.sub.2 Se.sub.3) and tin selenide (SnSe) added to and mixed with a dental amalgam alloy powder with the resulting powder mixture containing selenium regulated to an amount of 0.05 to 5 weight %.

Abstract: An amalgam-preparing chamber and mercury-capturing device therefor, which includes an amalgam-preparing chamber which is positioned on top of a mercury-capturing device, and wherein:(a) the amalgam-preparing chamber includes a space enclosed by a wall having a plate base at the lower end of the space, and wherein the wall has a transparent section, the base having a plurality of small openings into the mercury-capturing device; and an amalgam-preparing device in the enclosed space, and whereby the enclosed space is exposed to view by the transparent section in the wall, and further wherein the chamber has an openable door therefore; and wherein:(b) the mercury-capturing device includes:(i) an upper closed separation chamber in flow communication with the openings in the base, and(ii) a lower mercury vapor treatment chamber, wherein the upper and lower chambers are separated by an inclining partition which extends downwardly into a mercury reservoir groove with a discharge cock at the lower edge thereof, and w