<b>Superhydrophobic dental resin composites inspired by lotus effect for caries prevention</b>

Inspired by lotus effect, superhydrophobic dental resin composites (DRCs) composed of silanized nano-silica, perfluoroalkyl acrylate (FMA) and resin matrix were designed to present superhydrophobicity with a water contact angle (WCA) of 157.7° ± 1.0° and a rolling angle (RA) of only 2.6° ± 1.0°, and demonstrate robust stability by maintaining superhydrophobicity with WCA above 150° even after 7-day immersion in artificial saliva and 2500 thermal cycles.

The superhydrophobicity of the superhydrophobic DRCs was reached by synergistic effect of micro-nano structures constructed by nano-silica and low-surface-energy material modification of FMA to form a trapped air on the sample surface. The superhydrophobic DRCs can be easily applied onto tooth surfaces through standard clinical procedures such as fissure sealing and flowable composite application, to inhibit biofilm adhesion and prevent dental caries. <i>In vitro</i> studies show that superhydrophobic DRCs have good mechanical properties, including a Vickers hardness of 48.1 ± 2.1 HV, diametral tensile strength of 27.6 ± 3.0 MPa, compressive strength of 164.3 ± 21.9 MPa, and a friction coefficient of 0.22 ± 0.04, which are comparable to or better than those of commercial flowable resins and sealants, along with favorable properties and cytocompatibility.