Background: Denture cleansing is an important step that can prevent the spread of infection and improve a patient's health, the durability of the dentures, and the overall quality of life; therefore, it is necessary to choose a suitable cleanser that, in addition to being effective, does not have an unfavorable effect on the qualities of the denture base resin itself when used for an extended period.

Aim: This research aims to assess the effects of ozonated water on the surface roughness and hardness of heat-cured acrylic resin by immersion technique.

Materials: Sixty bars shape made of heat-cured acrylic were manufactured. Thirty samples for every test, including: (surface hardness and surface roughness). Then, these samples were divided into three groups, ten samples for each test group: The control group (immersion of samples in distal water) The group OZ-10 minute (immersion in 2mg/L ozone water disinfectant for 10 minutes) The group OZ-20 minute (immersion in 2mg/L ozone water disinfectant for 20 minutes) Next, the samples were tested using a profilometer tester and Vickers microhardness. Result: the hardness test readings were statistically significantly impacted by ozonized water but may be within clinically acceptable because the mean value was near. At the same time, the values of the mean roughness test did not significantly change (P>0.05) after soaking samples in ozone water among the groups.

Conclusion: Ozonized water had no adverse effects on heat-cured acrylic resin regarding surface roughness, but it did cause a decrease in hardness that was statistically significant but within clinically acceptable at 2mg/L concentration for (10 and 20) minutes.