What happens to current if I change dielectric from air to material with Ɛr>1
It's not completely clear if you are talking about a floating capacitor with no external connections and a fixed charge Q, or if this cap is somehow being used in a circuit.  Since you say "current" this becomes ambiguous because this implies the flow of charges.

From a electrostatics point of view, assume that the capacitor is not connected to anything but has a fixed initial charge Qo.

Q = CV so V = Q/C; and a voltage will be across the capacitor plates.

When you replace the dielectric, you will increase the capacitance.  So the voltage across the plates will decrease (for fixed initial charge Qo).

But if you are asking how the charging current on such a capacitor would change for the same input voltage, then it would increase.  This is because it now takes more charge to create a change in voltage on the plates (with the higher dielectric).