It is a white, biocompatible, aesthetic alloy.

Zirconia is mostly made for aesthetic purposes. In cases where discoloration and staining on the teeth can not be treated with tooth whitening methods, in cases where minimal invasive laminate veneer treatment that causes less damage can not be applied, orthodontic treatments are not able, in teeth with excessive material loss, in implant supported prostheses, as a bridge or coating and it is preferred to achieve a new smile aesthetics.

Grey metal is the infrastructure of classical porcelain bridges (PFM) and prostheses, while zirconium is a white alloy applied instead of this grey metal. Therefore, there is no grey appearance.

Yes. Because zirconia has a high light transmittance, less tooth substance is cut compared to normal metal fused restorations. 

Immediately, after the teeth are prepared and the impression is taken, the temporary teeth will be set in before you leave the dental chair. Your treatment is completed with in 7 days. During this period, you will be asked to visit the clinic for 3 sessions. If you have advanced gum problems, gum treatment is recommended first.

You can prevent the decay of the teeth under the restorations, that performed by your dentist according to the rules, with regular oral care, regular tooth brushing habits and dental floss.

Zirconia is biocompatible, so it does not cause any harm.

With dentist's correct tooth cutting, regular oral care, regular tooth brushing, use of dental floss bad breath is uninhabitable.

Your first choice  should be laminate veneer  because it causes less damage to dental substance. But laminate veneer also has mechanical and physical limitations. In cases where aesthetic concerns are important but laminate veneer can not be used, the most suitable material is zirconia. However, it should not be ignored that sometimes metal fused ceramics can be superior  to these two materials, although they are much more affordable. Follow your dentist's advice in choosing the correct materials.

Since zirconia is a biocompatible material, it doesn't cause allergies. You can have it done.