I agree with your dentist. Most patients don't realize all-on-4 is a very aggressive procedure. In addition to removing all teeth, a significant amount of bone needs to be removed and shaped prior to placing implants. Although most cases are successful in skilled doctors hands, there are plenty of cases that fail. When all-on cases fail, it's a disaster to redo the procedures. Some patients can be left crippled for the rest of their lives. I'm not trying to talk you out of the procedure, but I would encourage you to see if you can save as many teeth as possible and maybe consider placing implants simply where you are missing teeth. Another important fact about all-on restorations is that, homecare is very critical and it is more challenging to keep them clean on a daily basis, especially if the restoration is not properly design. This can lead to gum disease around implants and failure of the the entire restoration.
Zirconia is a go to material for a full arch restorations, nowadays. This material is very popular because it's ease of fabrication (CAD-CAM) and it provides strength and esthetics without utilizing metal base. However, not all cases warrants the use of this material, especially if there isn't enough space available to meet the thickness specification for the material. Not meeting the specification parameters for the material can lead to breakage and failure. Also the esthetics of the materials heavily depends on the skill level of technician. When it comes to selecting the ideal material for a full arch, it's important that the doctor can guide you through different materials for each individual. There are many materials available to provide longevity and the ultimate esthetics.
When it comes to restoring your entire upper teeth or both upper & lower, the design process has to involve how the teeth position, shape and length will change the face. The three essential components of all dental restorations should address, overall esthetics, function and longevity. When addressing these issues, communications with patient, doctors and all support team in designing the restorations have to be very experienced. The usual process of designing 'Full Face' restorations involve initial information gathering (CT scan, photos of face and mouth, full examination including overall health, models and preliminary smile design). From the initial information, computer simulations are done and approved from the patient. Then a trial smile restorations are made for the patients to try out prior to the surgery or actual procedure. Then at the time of surgery or procedure, a refined set of temporary restorations are placed in patient's mouth to evaluate overall esthetics and function. This process usually takes few visits. When both patient and doctors approve the design, then the final restorations are made. Also when it comes to choice of materials for the final restorations, there are many variety. Some lasts shorter time and prone to staining and breakage. So it's important that doctors and patients agree on the best choice of material for the patient's budget. Unfortunately, there are many clinics that skips few steps. It sounds like a few very critical steps of design and refinement of the temporary restorations was skipped in your case.
