Interesting. I hadn't heard of these before.
A couple years ago I lost a tooth to a rare condition called "external resorption". After examining the options, I went with a titanium implant. The worst part was having to go 6 months from extraction until the implant was put in, then another 3 months until the crown could be fitted. All the waiting was for the bone to grow in. Thank goodness it was not a front tooth!