Considering a QCD chiral symmetry breaking model where the gap equation contains an effective confining propagator and a dressed gluon propagator with a dynamically generated mass, we verify that the chiral symmetry is restored for a large number of quarks n(f) approximate to 7 - 13. We discuss the uncertainty in the results, that is related to the determination of the string tension (K-F), appearing in the confining propagator, and the effective gluon mass (m(g)) at large n(f). (C) 2015 The Authors. Published by Elsevier B.V.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)