© 2025 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the ''https://creativecommons.org/licenses/by/4.0/''Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.Dibaryons are the simplest system in which the baryon-baryon interaction, and hence the underlying quark-quark interaction, can be studied in a clear way. Although the only dibaryon known today is the deuteron (and possibly the d?), fully heavy dibaryons are good candidates for bound states because in such systems the kinetic energy is small and the high symmetry of the wave function favors binding. In this study, the possible existence of ?ccc?ccc and ?bbb?bbb dibaryons is investigated in the framework of a constituent quark model that satisfactorily describes the deuteron, the d?(2380) and the NN interaction. JP=0+ candidates are found in both systems with binding energies of the order of MeV. A ?-dibaryon candidate is also found.