Which condition is WORST for implant failure?

Osteopetrosis (marble bone disease) causes extremely dense, avascular bone that cannot support osseointegration — implants essentially cannot integrate in stone-like bone with no vascularity. Osteomyelitis is a post-op complication that can be managed/treated. Osteopetrosis represents an absolute contraindication, making it worse for implant prognosis than osteomyelitis.