How do you transition between a satin ceiling paint (in a kitchen) to a flat ceiling paint in dining rm?

We recently painted the kitchen ceiling and used a satin paint. The rest of the ceiling is painted in a flat paint. We tried the same satin paint, but the glare with normal sunlight and even overhead lights really made the ceiling shine. Please note that both paints are off white. Now we have a definite line from the kitchen to the dining room area. Should we put up some sort of 1/2 round molding or just leave it alone?