> Dentistry technology seems similar to battery technology in that these developments never seem to filter down out of the lab, ever.

What?

Batteries have made enormous strides in the past two decades. Surely, you remember the days of almost everything running off AAs, which took hours to recharge (If they were even rechargable), and tended to leak their contents at the slightest provocation.

Or, alternatively, you could shell out large amounts of money for lithium-ion batteries, which wouldn't hold half a charge after ~50 cycles, and which would be at 1/6th their original capacity after ~100 cycles.

If anything, battery technology has been a monumental success story. No, we don't have batteries based on unicorn farts that charge in 20 seconds, and hold more energy then gasoline. But what we do have is pretty damn amazing.