# Effects of Gastric Acid and Antiacid Medications on Surface Roughness, Morphology, and Optical Properties of Resin-Based Materials

## TL;DR

This study examines how gastric acid and antiacid medications affect the surface and optical properties of various resin-based dental materials.

## Contribution

The study introduces a comparative analysis of different resin-based materials under simulated gastric conditions and antiacid exposure.

## Key findings

- Gastric acid exposure significantly increased surface roughness and reduced translucency in all tested materials.
- CAD/CAM and paste-type composites showed higher roughness compared to 3D-printed and flowable composites.
- 3D-printed and flowable composites exhibited the highest fluorescence changes after exposure.

## Abstract

Effects of gastric acid and antiacid medications on the surface and optical properties of resin-based restorative materials were evaluated. A hybrid-CAD/CAM block, a 3D-printed resin, a paste-type composite, and a flowable composite were investigated (n = 9). Samples were prepared (1 mm thickness) and polished. All samples were exposed to gastric acid for 6 days, followed by a second exposure to distilled water, antiacid medication, or gastric acid for 56 min. Surface roughness, translucency, and fluorescence were assessed at baseline (T0), after gastric acid exposure (T1), and after the second exposure (T2). Surface morphology was examined by scanning electron microscopy. Data were analyzed with a significance level of p < 0.05. Gastric acid exposure caused a significant increase in surface roughness and a significant reduction in translucency in all materials (p < 0.05). CAD/CAM and paste-type composites exhibited significantly higher roughness values than the 3D-printed and flowable composites (p < 0.001). Fluorescence changes were observed in all groups, but the highest ΔE00 values were observed in the 3D-printed and flowable composites (p < 0.001). Gastric acid adversely affected the surface and optical properties of resin-based restorative materials, while antiacid medication showed limited, material-dependent protective effects.