  Chiral symmetry breaking in QCD is studied introducing a confining effective
propagator, as proposed recently by Cornwall, and considering the effect of
dynamically massive gluons. The effective confining propagator has the form
$1/(k^2+m^2)^2$ and we study the bifurcation equation finding limits on the
parameter $m$ below which a satisfactory fermion mass solution is generated.
Since the coupling constant and gluon propagator are damped in the infrared,
due to the presence of a dynamical gluon mass, the major part of the chiral
breaking is only due to the confining propagator and related to the low
momentum region of the gap equation. We study the asymptotic behavior of the
gap equation containing this confinement effect and massive gluon exchange, and
find that the symmetry breaking can be approximated by an effective
four-fermion interaction generated by the confining propagator. We compute some
QCD chiral parameters as a function of $m$, finding values compatible with the
experimental data. We find a simple approximate relation between the fermion
condensate and dynamical mass for a given representation as a function of the
parameters appearing in the effective confining propagator.
