Topical effect of polysaccharide cashew gum on the mitigation of dentin erosion progression under in vitro supraesophageal reflux simulation

Objective

To evaluate, in vitro, the topical effect of polysaccharide cashew gum (PLS-cg) on dentine subjected to erosive cycles that simulate refluxate contact in the oral cavity.

Design

Human dentine blocks were prepared, standardized, and randomly assigned to one of three treatment groups (n = 10): control group (C) without treatment, commercial dental varnish (CDV) 5 % NaF fluoride varnish, and PLS-cg extract (experimental group). The baseline enamel superficial microhardness (HK) and roughness (Ra) were assessed. The dentin was subjected to erosive cycles (6 × 5 min/day for 9 days) using a hydrochloric acid–pepsin solution (pH 2; 0.75-mg/mL pepsin). Surface roughness (Ra), microhardness (HK), percentage surface hardness loss (%SHL), and topographic analysis with scanning electron microscopy (SEM) were used to evaluate the protective heteropolysaccharide effect. Predictive molecular docking simulations were used to investigate possible interactions between PLS-cg and metalloproteinases (MMP2 and MMP9). The data were analyzed with two-way analysis of variance, t test, Pearson’s correlation, and Tukey’s test (p < 0.05).

Results

PLS-cg preserved HK significantly better than the control group (p < 0.001), with the lowest %SHL (-14.04 ± 8.22) and minimal Ra changes (0.124 ± 0.005). Pearson’s correlation between Ra and %SHL was significant and positive (0.7740, p < 0.001). SEM analysis revealed more prominent dentinal tubule openings in the control group, whereas CDV and PLS-cg showed tubule obliteration. Molecular docking identified possible interactions between PLS-cg and MMPs.

Conclusion

The findings indicate that PLS-cg may reduce dentine erosion caused by supraesophageal manifestations of gastroesophageal reflux disease.