Ok I didn't know that the HA paste doesn't show on a scan, hmmm so why would the ossified cartilage? Maybe this Dr was wrong and it does indeed become living bone,
I know a person who had cheekbone implants with Sailer, after 2 months he decided he didn't want them anymore. Sailer couldn't remove them by pulling them out, the bases had ossified and were connected to his bone. Surely then, he does place them on the bone?