Dentistry has come a long way since porcelain crowns that fractured easily. Today there are state of the art ceramic materials made from Zirconium and other high tech substances. The crowns are milled by machines that have received digital impressions of your teeth. Inlays - which are cast fillings, are also made by these same techniques and materials. They look very natural, and are bonded into place. Not all teeth are candidates for these types of crowns, but most front teeth will qualify.
Very often when a crown, or several crowns are needed on your front teeth - whether initially, or as replacements - it is a good time to think in terms of a makeover. It is an ideal time to whiten your teeth, as once the new crowns are placed, you won't have another such opportunity for 10 - 15 years. If you are replacing old crowns, then 2 weeks into your whitening treatment - your old crowns are removed, and white temporary crowns placed until treatment is finished.