In years past, and actually still most commonly today, dental implants were composed of several different pieces to fit together in the restoration area, and they were made out of titanium. Titanium is a metal, and, therefore, BAD (in a holistic sense, of course) inside a human body. The titanium implants also presented other drawbacks, such as aesthetics (metallic coloring would show through the crown) and complications with assimilation into the maxilla or mandible — the facial bones that shape your mouth/jaw and anchor your teeth down.
Zirconium implants are made entirely from a special ceramic that has a chemistry similar to our bones and, specifically, teeth. Not unlike what the CEREC machine spits out, this material is entirely biocompatible and ideal for its similar strength, durability, and beauty of a natural tooth. There has been great success with its conforming to surrounding facial bones as well. Because of its biocompatibility, our bones do not reject its chemical makeup, therefore preventing infection and weak implants.
Dr. Sperbeck, West Los Angeles