Parece que sua conexão não está usando UTF8
Mudar
app_persistance.connection.url=jdbc:mysql://localhost:3306/dentapp
para
app_persistance.connection.url=jdbc:mysql://localhost:3306/dentapp?useUnicode=true&characterEncoding=utf-8
app_persistance.connection.url=jdbc:mysql://localhost:3306/dentapp
app_persistance.connection.url=jdbc:mysql://localhost:3306/dentapp?useUnicode=true&characterEncoding=utf-8
