Prosthodontics Speciality is not about doing big (full mouth restoration), but doing small (details). Take the dental crown (cap) or ceramic veneers as an example, they seem to be an easy common procedure, actually need a lot of details to meet the American dental association ADA standards of margin seal ( 360 degrees no leakage, less than 50-micron marginal gap), proximal contact (no food impaction), occlusion (bite comfortably), meet the standards of the strength of crowns so to withstand the chewing cycle for a long term, esthetics ( translucency, color match, buccal corridor, etc). Missing some of the details might not manifest any issue in the first 5 years in some people, but after several more years, the issues start to come out.
Terry Donavan's classical article reported high-quality crowns made by board-certified Prosthodontists had a survival rate of 94.1% for 40 years ( Donavan T, et, al Journal of Esthetic and Restorative Dentistry 2004,16(3):194-204). There are reasons behind it. Images show our board-certified Prosthodontist Dr.Qing still trims the die himself ( one important detailed step of stone model work) to ensure the 100% seal of the margin and long-lasting crown. Then the master ceramist mixed the porcelain with different shades to match the crown color to the tetracycline-stained teeth, which needs a lot of skills and attention to detail.
The crowns were then tried to make sure they meet all the Prosthodontics standards before delivery. One of the most important steps is to use a Bitewing Xray to check the marginal seal. ( arrows indicate the perfect seal, no bulky overhang or gap)