Purpose: The aim of the present study was to evaluate the effect of denture cleansers on the flexural strength, color stability and surface roughness of flexible denture base resin as well as micro wave cured denture base resin. Materials and Methods: A total of 144 specimens were fabricated. Seventy two specimens were constructed from each type of resin and were further subdivided into 3 subgroups (n=24) according to their immersion in different types of denture cleansers. Subgroup1: distilled water (control), subgroup 2: 5% sodium hypochlorite and subgroup 3: effervescent alkaline
tablets (Corega tabs). The color changes and surface roughness were measured for each subgroup before (baseline) and after immersion in the solutions. The flexural strength was also measured after their immersion. Results: For both groups (flexible denture base resin and microwave cured denture resin groups); control subgroup showed the statistically
significant higher flexural strength values, while subgroup treated with Corega Tabs recorded the statistically significant lowest flexural strength values. Regarding the color changes, for both groups (flexible denture base resin and microwave cured denture resin groups); subgroup treated with Corega Tabs recorded statistically significant highest (ΔE) mean values, followed by subgroup treated with sodium hypochlorite then the control subgroup. However, there was a statistically non-significant difference of the Ra values between the tested groups and subgroups. Conclusions: Within the
limitations of the study, it was concluded that the tested denture cleansers had no effect on the surface roughness of flexible and microwave cured acrylic resin, however, significantly influenced their flexural strength. Moreover, denture base polymers are susceptible to color change on immersion in Corega Tabs.