  We study the effect of quantum and thermal fluctuations as well as the mass
dependence of the phase structure of QCD at finite temperature and density
within a dynamical Polyakov-loop--extended quark-meson model. The glue dynamics
is simulated by the Polyakov-loop potential, also including the back-coupling
of the matter sector to the glue dynamics. In the chiral limit, the chiral
phase transition at large chemical potential and low temperature splits into
two transition branches. For non-vanishing pion masses the chiral transition at
small chemical potential changes from a phase transition to a crossover. We
close with a discussion of a systematical improvement of the current model
towards full QCD.
