8Eliopoulos D,Zinelis S,Papadopoulos T.The effect of investment material type on the contamination zone and mechanical properties of commercially pure titaniun castings[J].J Prosthet Dent,2005,94(6):539.
9Yu Guilin,Li Nan,Li Yousheng,et al The effects of different types of investments on the alpha-case layer of titanium castings[J].J Prosthet Dent,2007,97(3):157.
10Spiros Zinelis.Surface and elemental alterations of dental alloys induced by electro discharge machining (EDM)[J].Dent Mater,2006,23(5):601.
