Busser is right. In a steady turn, the Angle of attack is the same. The lift vector is perpendicular to the wing. So if there is dihedral, the vertical component of the lift vector is greater from the lower wing which tends to roll the aircraft back level. To keep most aircraft in a turn you have to hold a small amount of aileron - if you centralise the yoke the aircraft will tend to roll back to wings level. The angle of attack is significantly different as you roll into or out of a turn because the wings are moving up or down relative to the free stream and that will tend to oppose the roll but that effect is the same whether you have dihedral or not.