There are some quite old crypto projects that has emerged in the last bull run in 2017 and survived till now nevertheless that they were perceived already dead. It is a great spot to know how to take care of your oral health, there are plenty useful hints and tips. On the other hand I am unable to see any use case in utilizing blockchain. It can work easily without blockchain. They have also great products - such as app for toothbrushing - timer, kids version, paid surveys, etc.
The platform is overall helpful and great but their token DCN is too volatile and not good idea to investment in at all.
In this late bull run you can profit from the price surge and sell some of your free tokens which can be obtained for filling in surveys and some other tasks (promotions, in app etc.).
I had some issues with the team and overall attitude to solving some issues was not what I would expect.
Worth to mention that there are some automated processes on their site which are quite not working as they should be.