The structural properties of melts of poly(butyl)carbosilane (PBC) dendrimers of the third (G3), fifth (G5), and sixth (G6) generations were studied by molecular dynamics simulation at 600 K. A substantial difference was found between the density of the melt of the G6 generation dendrimer and the densities of the melts of the G3 and G5 generation dendrimers. The obtained computer simulation results do not confirm the hypothesis that these differences are caused by physical entanglements between the branches of the neighboring dendrimers (which take place for G6 to a higher extent) and indicate, most likely, the minimization of the interdendrimer free volume due to a more regular packing.