Dentacoin is still availible. On their blog they have claimed that 2 clinics accept dentacoin. Lifdental in NY usa) and qadental in hemel hempstead UK. Both clinics do have websites and a Facebook page that is going back untill 2016 (stopped scrolling after that). On the Facebook pages a lot of reviews. Both websites are telling about dentacoin. So, i will send them an email verifying if dentacoin can be used.

For now it looks like, dentacoin is real.