The Effect of Mouthwashes on the Flexural Strength of Interim Restorative Materials
Materials and Methods: Based on ADA specification #27, 50 identical 25×2×2 mm samples were fabricated from five interim materials (TempSpan, Protemp 4, Unifast III, Trim and Revotek LC) and stored for 14 days at 37°C in three different mouthwashes (Listerine, Oral B and Chlorhexidine) and distilled water (control group). After conditioning, the flexural strength values were assessed by a universal testing machine. The standard three-point bending test was conducted on the specimens at a crosshead speed of 0.75 mm/min. Data were statically analyzed by the two-way ANOVA and Tukey HSD tests. Results: The mean ranks of flexural strength of the examined materials were as follows: TempSpan= 121.10, Protemp 4= 111.93, Unifast III= 63.44, Trim= 62.83 and Revotek LC= 46.55.There was no significant difference between Unifast III and Trim, however; the other materials showed significant differences. Both bis-acryl resin composite materials showed higher flexural strength than the methacrylate and light-cured resins after 14 days storage in mouthwashes. One of the bis-acryl resins (TempSpan) showed the highest flexural strength. The light polymerized resin (Revotek LC) presented the least flexural strength. Conclusions: The mouthwashes employed in this study did not show any statistically significant effect on the flexural strength of the five tested interim materials.