How much does implant lifespan vary depending on how it is maintained?

I've heard that implants are artificial teeth, but depending on proper care, they can last a long time, or they can need to be replaced quickly if problems arise. They say brushing alone isn't enough; you need to thoroughly care for the space between your teeth, and flossing at least once a day is recommended. They also say you should get a dental checkup if you experience even the slightest discomfort... I'm curious about the average lifespan of implants.