Hello, I am glad that you have chosen to undergo this treatment as it can be a life changing one. The main difference between porcelain fused to metal(PFM) and full porcelain crowns and bridges are the translucency of the material. Before we had high strength porcelain ceramic restorations, PFMs were the material of choice. They provide a strong foundation for a crown or bridge and a much more natural esthetic look than a full metal. However, in order to block the metal from showing through an opaque layer of porcelain is used to cover the metal substructure which blocks light and prevents the teeth from having a natural translucency. Today, we have high strength ceramics that hold up relatively well to the forces our teeth are subjected to, but are also made from more translucent material that looks more natural. So, to answer your question, the full porcelain ceramic restorations would look noticeably different because of this difference in translucency but a skilled lab technician may be able to disguise it well. Though I don't know the specifics of your case, you may ask your dentist about using full porcelain ceramic instead for an ideal esthetic result.
In my experience it takes 4-6 weeks, but sometimes up to 8 weeks. This is from the date the pre-approval is submitted. Your dental office should have submitted for a pre-approval after your initial exam. After extractions there is a waiting period for mouth and bone to heal a remodel. Every dentist has their own preference for how long to wait. If you have further questions please contact your dental office, they should be able to answer these questions for you.
It looks like you are in need of a very good cleaning(Probably a scaling and root planing or "deep cleaning"). A dental school or dental hygiene school could be a good resource for you, as they offer services at a heavy discount. Check to see if there are any in your area. You may consider paying cash as an option. Some dental offices offer discounted rates for patients paying cash. You could also see if you qualify for a government insurance program that would cover dental expenses. Until you can see a dentist, focus on a good hygiene regiment.
There are many factors at play when it comes to determining proper esthetics of your smile. You have provided one photo which does not give us enough information to make a definitive judgment. It is likely that some improvements can be made to make your smile more appealing to you. Some more pictures would be helpful to determine if these can be done with resin bonding or if more extensive treatment is necessary. I would encourage you to find a cosmetic dentist in your area and have a consultation with them to see what the right treatment would be for you.
It sounds like this could be a problem with the way the tooth was prepared for the crown. You haven't provided much information, but there are many factors that play a role in how well a crown will stay on a tooth. There might not be enough tooth left underneath the crown to hold it on properly. Sometimes we need to place a post and buildup a core on the tooth so that there is enough structure there to retain the crown. Alternatively, your dentist may need to refine the way the tooth is reduced and make a new crown that will stay on better.
