Possibly, because you ever have trusted your dentist?! Dentacoin is in a way a worldwide bounty system in the dental field. Everybody gets some coints who is involved. Dentists get evaluated, patients rewarded - rewarded on the one hand for regular dentist visits (more customers for dentists, prevention), on the other hand for writing evaluations (better treatment quality). If Dentacoins are accepted, you can also reduce your dentist bill. Possibly you live in a country where this does not matter, in many country this matters. And a reward in money everybody likes.