Protective effects of herbal toothpastes against dentin erosion: an in vitro study

This in vitro study evaluated the protective effects of different herbal and bioactive toothpaste formulations on dentin surfaces exposed to erosive challenges. A total of 96 dentin specimens were prepared from 48 human molars and randomly assigned to six groups (n = 16), each receiving one of the following treatments: fluoride-containing toothpaste, clove-containing toothpaste, propolis-containing toothpaste, fluoride combined with nano-hydroxyapatite (F+nHAp), nano-hydroxyapatite toothpaste (nHAp), and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) based toothpaste. The specimens underwent repeated erosion-brushing-remineralization cycles using 0.01 M hydrochloric acid (pH 1.5) to simulate intrinsic erosive conditions. Surface roughness and microhardness were measured at baseline, after demineralization, and following remineralization. Additional surface characterization was conducted using scanning electron microscopy (SEM) and atomic force microscopy (AFM). All groups showed increased surface roughness after demineralization. However, only the clove group exhibited a significant reduction in roughness after remineralization (p < 0.05), returning to baseline levels. Microhardness significantly decreased in all groups following demineralization (p < 0.05). After remineralization, only the clove, F+nHAp, and nHAp groups regained microhardness values comparable to baseline (p > 0.05). These findings demonstrate that clove-containing, nano-hydroxyapatite-containing, and fluoride+nano-hydroxyapatite toothpaste formulations were the most effective in preserving dentin surface integrity, suggesting their potential role in the prevention of dentin erosion.