Re: 3D Printing
Ljb makes some good points, particularly about the analysis capability of ordinary modeling programs like Pro-E or SolidWorks. (I use SolidWorks all the time BTW.) I think 3D printing will be useful in the future for one-off parts, and possibly things with complex shapes like that jaw prosthesis that are difficult to make by conventional methods. The major cost advantage is that high-class machining takes expensive machines and a highly skilled person. A 3-D printer doesn't.
I don't see it being used in ordinary series production for a long time, if ever. Look at standard printing; one-off documents are printed by ink-jet or laser. Mass-production books are not, and never will be.
"For a successful technology, reality must take precedence over public relations,
for nature cannot be fooled."