[Casting of dental alloys with special reference to the bonding capacity of Ni-Cr alloys].

A short review on castability of dental alloys -- for which a definition is proposed -- reflects the different factors influencing the results of a casting. In this case solid sieves and plates are cast by use of one gold-base alloy (Type III) and two base metal alloys used for porcelain veneering. All three alloys filled the sieve pattern to a 100%, whereas they performed differently when cast as thin, solid squares. The most continuous results were achieved with a Ni-Cr-alloy whose melting temperature can be recognized since the ingots flow together when this point is reached. Since the plate pattern is most difficult to cast due to surface to bulk ratio it is assumed that a complete casting can only be achieved when the performance of the alloy is good and all required conditions match. Thus, this type of test seems to be suitable to determine the castability of a dental alloy. The sieve test should be used to investigate and to improve the influence of the different factors as for example burnout time and temperature of the mold and sprue size.