Amd athlon 2 quad core 64 bit. what temperature is normal for this processor?

my processor stays about 80 degrees ferenheit at idle. and 112 degrees ferenheit running splintercell conviction or other games. about 90 degrees playing a movie. it is 75 degrees in my room right now. do you recommend a dusting and reaplying thermal grease? its been 2 years. thanks