Most likely it will, but it may not lower it anymore than what you have. Arctic silver is arctic silver because it has an insanely high content of silver in it to optimize heat transfer. I'm not sure about the stuff you are currently using, but if it has an equal amount of silver concentration in it, than getting arctic silver will most likely not lower your temps.
What some people overlook is how much of an impact application and proper burning in of the thermal compound has on performance. You have to use a very small amount (about the size of a grain of rice, 50% more than that for an AMD) directly on the center, clamp on your heatsink nice and level, and run some burn in programs. It takes about a week for the stuff to melt and settle into the best places it can go to conduct heat.