Most dental implants today are made out of titanium or an alloy of titanium. An alloy is when several metals are blended together. The most common dental implant alloy is made of titanium, aluminum, and vanadium. The ratio of metals is 90 parts titanium, 6 parts aluminum and 4 parts vanadium. The titanium alloy is stronger than the pure titanium.
Bone grows onto and bonds to titanium and this is called osseointegration. A successful dental implant bonds so tightly to the jaw bone that it does not move at all. This is why a loose dental implant is a really bad sign.