Full Arch Hybrid Prosthesis: Legitimate?

My wife is in need of oral surgery. She has had several implants and crowns where bone decay has necessitated costly rework. Recently, we were recommended to look into oral surgery as a long-term solution and we were referred to a clinic that offers a "Full Arch Hybrid Prosthesis" surgery. I have heard of the All-on-4 (or 6), and Implant Dentures. But is the surgery in the attached photos legitimate/safe, or is this just a fancy cosmetic operation?

If this is a legitimate and established form of oral surgery that suits my wife's dental needs, then we have to pick a finish: PMMA or Zirconia. What are the nuances between the two finishes? Is Zirconia the obvious choice for long-term sustainability? Thanks in advance for any advice.