earticle

영어

The purpose of this study was to evaluate the titanium castability (internal porosity) between
pressure type casting machine & centrifugal casting machine with air-vent or not.
Internal porosity is a well-known problem in dental titanium casting, resulting in inferior
mechanical properties of dental restorations.
To evaluate the castability, the square plate was chosen. 40 plate patterns(20 20 1.8 )were
attached to funnel-shaped sprue. Then 20 plate patterns were attached air-vent.
They were invested in titanium investment material and cast in a pressure type casting
machine(20castings) and centrifugal casting machine(20castings). Each group were divided with
air-vent(10castings) or not(10castings).
The titanium castings were evaluated by radiographic photograph for the location of the internal
porosities.
The percentage porosity of each specimen was determined using standardized digital
radiographs.
The results were analyzed with analysis of variance and t-test for paired comparison between two groups.