We use a sample of 33 H II regions with high and intermediate resolution spectroscopy to analyze the radial distribution of different elements in the Milky Way. This sample covers Galactocentric distances from 6 to 17 kpc, which have been revised using Gaia DR2 parallaxes. We calculate physical conditions and chemical abundances using updated atomic data. We compare and discuss different ionization correction factors and considerations about the temperature structure of the nebula to improve chemical abundance determinations. We determine the radial abundance gradients with an unprecedented precision. The re-evaluation of the distances using Gaia DR2 parallaxes produces an O gradient that disproves previous claim of a possible flattening of the gradient in the inner zones of the Galaxy. The radial distribution of Ne/O, S/O, Cl/O and Ar/O are almost flat confirming a lockstep evolution of those elements respect to O. Our Galaxy also shows an almost flat N/O gradient, in contrast with the common behavior in other spiral galaxies. However, C and C/O show stepper gradients than the other elements in agreement with the results of other spiral galaxies.