Can I still build when switching to much lower weights?

I usually bench 225 upwards and 170 military press. I wont be able to do any press exercises with heavy weights for a while and have to use much lighter weights (two 50 lbs dumbells). Ill supplement with flys and other exercises but obviously push exercises are core for chest and shoulder development for a reason. Can I effectively offset the loss of weight with a lot more reps?