Enhancing Electrokinetic Transport on the Enamel Surface of Tooth Using Multiscale‐Pore Membranes

Therapeutically reconstructing hard tissues such as dental enamel, bone, or cartilage via material infiltration is highly desirable for medical applications. However, the nanoporous structure of hard tissue renders infiltration inherently challenging and techniques have relied on passive diffusion, limiting their effects mainly to the surface area. Recent innovations in material infiltration utilizing electrokinetic transport capable of deep (approximate to 1 mm) infiltration have been introduced. Despite the potential of electrokinetic infiltration, there are wide discrepancies among reported results, limiting its practical use. A device for real-time visualization and electrical measurement is developed to investigate the underlying electrokinetic phenomenon on the surface of teeth that prevents effective electrokinetic infiltration. Herein the first direct and detailed analysis of the generation of an ion-depleted region on the surface of dental enamel is presented this depleted region significantly hinders electrokinetic transport and may be behind the mixed outcomes of earlier infiltration studies. Furthermore, a novel approach adopting a multiscale pore ion-conductive material to enhance electrokinetic transportation is proposed. The near-complete elimination of the ion-depleted region and improved (ohmic) electrokinetic infiltration is demonstrated. The presented study overcomes inherent limitations of electrokinetic infiltration to provide an efficient, regulated, localized, non-invasive, and safe method for delivering materials into hard tissues.