Introduction: The prosthesis base materials should have the necessary and sufficient quality to resist the various chemical compounds in the mouth and various pressures. This study investigates the effect of propolis disinfectant solutions on the mechanical and physical properties of polycarbonate prosthesis base materials.

Materials and Methods: In this study, 120 polycarbonate samples were prepared and analyzed in 4 main groups (to test impact strength, hardness, surface roughness, and color stability) and 3 subgroups (control, 5% propolis, and 10% propolis). Rod samples with a length of 80 mm, a width of 10 mm, and a thickness of 4 mm were used for the impact strength test, Rod samples with a length of 65 mm, a width of 10 mm, and a thickness of 2.5 mm were used for surface roughness test and hardness test, and rectangular sample with a length of 20 mm, a width of 10 mm, and a thickness of 0.8 mm were used for color stability. After flasking, polycarbonate injection was done to prepare 30 samples of each. All the samples were finished and polished, except for the surface roughness test samples, which were only finished. Ten samples from each group were immersed in distilled water, 10 samples in 5% propolis solution, and 10 samples in 10% propolis solution for 10 minutes at room temperature. This process was repeated 180 times. Then, impact strength, hardness, surface roughness, and color stability tests were performed. Data were analyzed in SPSS 22 software using One-way ANOVA, Kruskai Wallis, and Mann-Whitney tests.

Results: Disinfection solutions of 5 and 10% propolis did not cause significant changes in the hardness and impact resistance of the polycarbonate denture base compared to the control group (distilled water). Significant reduction of the surface roughness of the polycarbonate denture base by immersion in 5 and 10% solutions Propolis was observed compared to the control group (distilled water) (P value=0.003), but there was no significant difference between the two concentrations of 5% and 10% of propolis. Also, immersion in 5% and 10% propolis solutions caused a significant change in the color of the polycarbonate denture base compared to the control group distilled water (P value=0.003), but there was no significant difference between the two concentrations of 5% and 10% propolis. Of course, this color change was not clinically detectable (?E < 1).

Conclusion: Concentrations of 5 and 10% of Propolis solution did not cause an unfavorable impact on the hardness, impact strength, and surface roughness of the polycarbonate denture base. Thus, it can be used as a disinfection solution for polycarbonate denture bases.