I cannot save password encrypted with bcrypt in the database

Question

I encrypt the password with bcrypt and when I will enter in the database it just won’t go but if I put anything else works what I can do ?

                    $senha = \DarkDevs\Bcrypt::hash($senha);

                    $registro = \DarkDevs\MySql::connect()->prepare("INSERT INTO usuarios VALUES (null,?,?,?)");

                    $registro->execute(array($nome,$email,$senha));