Effect of erosive challenge with HCl on restorative materials

Investigate the effect of erosive challenge with hydrochloric acid (HCl) on the surface of five different restorative materials.

Ten plates of five restorative materials (Admira Fusion, Activa BioActive-Restorative, Charisma, Equia Forte HT Fil/EF, Filtek Universal Restorative/FU) were obtained. Half of the plate surfaces was covered with an adhesive tape, creating a control area, and the other side was submitted to the HCl (0.06 M HCl; pH 1.2; at 37 °C; for 30 h). Plates with control and HCl-treated areas were analyzed regarding the surface roughness (Sa), roughness profile (Rv), surface loss (SL), microhardness (MI), and gloss (GL) (n = 10). Surface morphology was analyzed by SEM and chemical elements were identified by EDX (n = 5). Data were evaluated by ANOVA and Tukey's test (α = 0.05).

Most materials were not affected by HCl. FU showed the lowest Sa and Rv, and the highest GL after HCl. On the other hand, EF presented the highest Sa, Rv, and SL, and the lowest GL. The MI of materials was not changed after HCl. Topographical and chemical alterations were observed after HCl only for EF.

The composites showed minor surface changes after HCl, which was not observed for the glass ionomer cement (EF). FU presented the best performance regarding the parameters evaluated.

The effects of erosive challenge with HCl on composites were minimal, while the glass ionomer cements might not be indicated as restorative material for patients with gastroesophageal reflux disease.