Nanoleakage in Dentistry: 30 Years Later

This letter addresses the article recently published by Medina et al. (1). In their in vitro study, the authors evaluated the marginal sealing of a bulk-fill nanocomposite. They found that marginal sealing varies by curing protocols and aging processes, evidencing the need for optimizing curing protocols to provide better long-term durability of composite restorations. Notably, they used microleakage and thermocycling; the former was measured with dye penetration. The authors clearly point out the limita-tions of their study (1), however it is salient to recognize that, although dye penetration is a very popular method used by many authors, several weaknesses have been reported for this model by prominent dental journals (2) and authors in this Journal (Brenes-Valverde et al., for example) (3). In their manuscript, Medina et al. state that “with progress in nanotechnologies and an increasing availability of nanocompo-sites....”, new classes of composites are emerging (1). In this regard, we believe the nanoleakage model would have been more appropriate, as it better corresponds to the nanoleakage scale.