In hip-hop culture, the term grills refers to cosmetic dental
metal apparatus featuring silver, gold, or platinum caps with
diamond inlays (usually princess-cut diamonds) jewelled to be worn
over the teeth. Grills rose to prominence with Dirty South rappers
in the 1990s as a symbol of their wealth and success. But are also
worn by some rock artists, such as Korn, Marilyn Manson, and Kyo
from Dir en grey. The video to the 2005 single "Grillz" (by Nelly,
Paul Wall, Big Gipp, and Ali) showcases many common styles of
grills. Grills can be purchased online or at specialty shops.
Grills are also known as Fronts, Golds, Plates, Gold Grills,
Shines, Caps, Slugs, Pullouts.
While some grills are made to be removable similar to that of a
orthodontic retainer, others are permanently bonded to the teeth of
their owners.
from http://en.wikipedia.org/wiki/Grill_%28jewelry%29
for more info
http://www.myspace.com/colossus_grillz
do they have these in singapore? 
