Cast porcelain crown: Because the whole cast porcelain crown is translucent ceramic material, which is very close to natural teeth, other types of porcelain crowns have opaque metal inner crowns, so cast porcelain crown is the best choice for cosmetic restoration of teeth closest to natural teeth and tetracycline teeth.
Precious metal (gold alloy) porcelain crown: the aesthetic effect is second only to that of cast porcelain crown, mainly because the color of gold alloy inner crown is close to the yellow of natural dentin, but it is slightly impermeable and unnatural compared with cast porcelain crown. Because the bonding force between precious metals and ceramics is the best, the precious metal porcelain crown is not easy to collapse and durable. Gold alloy has good biocompatibility and will not cause discoloration of surrounding tissues.
Titanium alloy porcelain crown: titanium alloy has a good bonding force with ceramics, so titanium alloy porcelain crown is also durable and not easy to collapse. Titanium alloy has good biocompatibility and generally does not cause discoloration of surrounding tissues. However, due to the gray metallic color of titanium alloy porcelain crown, the restored titanium alloy porcelain crown will show an imperceptible blue color under special light, and its cosmetic effect is not as good as that of precious metal porcelain crown.
Nickel-chromium alloy porcelain crown: because the color of nickel-chromium alloy inner crown is dark gray, its beauty effect is the worst; The bonding force with ceramics is lower than that of titanium alloy, and the porcelain crown of nickel-chromium alloy is prone to porcelain collapse. Nickel-chromium alloy has poor biocompatibility, and long-term use will cause gingival black line. The biggest advantage of Ni-Cr alloy porcelain crown is its low price.
The first composite resin restoration method you mentioned is to polish a layer of tooth surface first, and then use a white composite resin to rebuild the tooth surface and repair the shape. The disadvantage is that the composite resin sometimes covers the color badly and is used to send blue! Easy to fall off ~
The third tooth whitening patch, similar to the first one, uses plastic teeth without plasticity instead of composite resin. Polished as bright as teeth ~ easy to fall off.
The most recommended time is porcelain crown restoration.
I hope to help you again.