the list is very long from breast implant.. to heart pacemaker...to artifical bone joints...to sex change...to hearing aids..
that's one of the major attributes that make human different from other animals.
One day, human will be confronted with the issue: replace ther carbon based brain with silicon one
...Look at it this way, the silicon brain could keep living indefinitely even after the other carbon based body parts die ===> cyber immortality
---plagues come and go...