Effects of Acidic Media on the Mechanical and Optical Properties of Digitally Designed Restorative Materials.

OBJECTIVE

This investigation assessed how acidic environments affect the optical behavior, surface roughness, and hardness of a newly developed 3D-printed permanent resin compared with commonly used computer-aided design/computer-aided manufacturing restorative blocks.

MATERIALS AND

METHODS

The materials tested were lithium disilicate, a polymer-infiltrated ceramic network, a nanoceramic resin block, and a 3D-printed composite. Specimens were stored in hydrochloric acid and Coca-Cola, with distilled water as the control medium. Changes in color, translucency, roughness, and hardness were measured before and after immersion. Data were analyzed using R (v4.5) with a significance level of p < 0.05.

RESULTS

Lithium disilicate showed the greatest resistance to acidic conditions in both optical and mechanical properties. The polymer-infiltrated ceramic network and filler press and monomer infiltration materials showed intermediate stability under acidic challenges across all measured parameters. The 3D-printed resin was the least stable material. Gastric acid caused more pronounced deterioration than Coca-Cola, while water produced minimal changes.

CONCLUSIONS

Acidic exposure negatively affected the performance of all tested restorative materials. Lithium disilicate remained largely unaffected, whereas the 3D-printed permanent resin showed significant vulnerability. These findings emphasize that material choice is critical for patients prone to erosive challenges such as reflux or frequent soft drink intake.