Background and Aim: Gastroesophageal reflux disease causes gastric acid to enter the oral cavity, leading to mucosal changes and deterioration of dental hard tissues and materials. The purpose of this in vitro study was to evaluate the impact of gastric juice on the surface roughness of two types of acrylics used in provisional restorations. Materials and Methods: Acrytemp ® and Temdent acrylic resin discs (10 × 2 mm) totaling 80 were manufactured and divided into eight groups (n = 10). Groups were prepared as follows: Group 1 (Temdent + Universal Polish) (control), Group 2 (Temdent + Universal Polish + Biscover LV), Group 3 (Temdent + Universal Polish + Resin Glaze), Group 4 (Temdent + Universal Polish + Fortify Plus), Group 5 (Acrytemp + Universal Polish) (control), Group 6 (Acrytemp + Universal Polish + Biscover LV), Group 7 (Acrytemp + Universal Polish + Resin Glaze), and Group 8 (Acrytemp + Universal Polish + Fortify Plus). The resin discs were immersed in distilled water for 24 h and in gastric juice (pH = 2) for additional 24 h. The initial and final roughness values of samples were measured and analyzed with non-parametric statistics including Mann-Whitney U-test for pairwise comparison, Kruskall Wallis test for comparing more than two groups, and Wilcoxon signed rank test for within-group comparison (P < 0.05). Results: Surface roughness did not differ significantly between control groups. It notably increased for all samples with surface sealants, both initially and after gastric juice immersion (P < 0.05). Conclusion: Surface sealants noticeably increased the roughness of two types of acrylic resins. After immersing in gastric juice, Group 4 (Temdent + Universal Polish + Fortify Plus) showed the highest roughness, while the untreated control groups remained the smoothest.