  Stellar ages are key to improving our understanding of different
astrophysical phenomena. However, many techniques to estimate stellar ages are
highly model-dependent. The lithium depletion boundary (LDB), based on the
presence or absence of lithium in low-mass stars, can be used to derive ages in
stellar associations of between 20 and 500~Ma. The purpose of this work is to
revise former LDB ages in stellar associations in a consistent way, taking
advantage of the homogeneous \textit{Gaia} parallaxes as well as bolometric
luminosity estimations that do not rely on monochromatic bolometric
corrections. We studied nine open clusters and three moving groups
characterised by a previous determination of the LDB age. We gathered all the
available information from our data and the literature: membership, distances,
photometric data, reddening, metallicity, and surface gravity. We re-assigned
membership and calculated bolometric luminosities and effective temperatures
using distances derived from Gaia DR2 and multi-wavelength photometry for
individual objects around the former LDB. We located the LDB using a
homogeneous method for all the stellar associations. Finally, we estimated the
age by comparing it with different evolutionary models. We located the LDB for
the twelve stellar associations and derived their ages using several
theoretical evolutionary models. We compared the LDB ages among them, along
with data obtained with other techniques, such as isochrone fitting, ultimately
finding some discrepancies among the various approaches. Finally, we remark
that the 32 Ori MG is likely to be composed of at least two populations of
different ages.
