Hi guys, I am new here,
I downloaded demo of ZB (few days ago)
and I cant find a Dynamesh Button in Geometry pannel:
http://i.imgur.com/KQyfG.jpg
Could you help me?(I think trial version is full version just limited by time)
Thanks for responds 
DynaMesh is a ZBrush 4R2 feature. The Trial is currently ZBrush 4 – the version before DynaMesh.