Ultrastructural, Chemical, and Wettability Insights into the Interaction between Novel Natural Dentifrices and Nanohybrid Composites: A Multi-Technique Microscopy Approach

Abstract

Abstract This study aims to provide a multimodal ultrastructural and microanalytical characterization of the effects of essential-oil and ozonated-oil toothpastes on a zirconia-reinforced nanohybrid composite resin. Fifty composite specimens were distributed into five groups: artificial saliva (AS), conventional toothpaste Colgate Total 12 (CT), Colgate Natural Extracts Reinforced Defense gel (CN), DoTERRA on guard (DT), and Ozonecare gel (OZ). Following simulated brushing, a comprehensive surface assessment was performed using micro energy-dispersive X-ray fluorescence spectrometry (μ-EDXRF) for elemental mapping, contact angle (CA) measurements for surface-free-energy analysis, and scanning electron microscopy (SEM) for topographical evolution. Dentifrice components were further characterized by SEM, μ-EDXRF, and FT-Raman spectroscopy. A significant decrease in oxygen was detected only in the CN group. Increased Si, Ba, and Ti content was observed in the AS and CN groups. Reductions in CA occurred after brushing with CT and DT. Increased CA was found in AS. No significant changes in wettability were found using CN or OZ. SEM analysis revealed extensive morphological impact and increased filler exposure in samples treated with CT, moderate degradation with DT, and minimal morphological impact with CN and OZ. Particle analysis demonstrated the presence of larger, irregular abrasives in CT, silicate-rich particles in DT, and homogeneous fine particles in both CN and OZ. FT-Raman spectroscopy detected TiO2 exclusively in CT and prominent silicate bands in DT. The toothpaste formulation significantly affected the composition, wettability, and morphology of the composite resin. Notably, OZ gel preserved both the elemental composition and surface morphology of the composite.

The authors' abstract, as published at the source. ACS Omega, 2026 · DOI ↗