Objectives: The aim of this study was to compare two disinfection methods (microwave
disinfection and chemical immersion disinfection) and to determine the best disinfection
method for the gypsum cast which produce the least changes on compressive strength.
Materials and Methods: A total of 36 specimens were prepared using standardized carbon
steel dies. The specimens were divided into three groups (n=12 each): Control group
contains gypsum rinsed with distilled water, Study group I consists of gypsum casts
immersed in 0.5% Sodium Hypochlorite and Study group II consists of gypsum casts
irradiated in a microwave oven. Compressive strength of the specimens was evaluated using
a universal testing machine, where each specimen was placed on the test platform and
compressed to record the deformation at various loads.
Results:In this study, the mean compressive strength values obtained were 24.69 MPa for
Group 1, 13.77 MPa for Group 2, and 23.93 MPa for Group 3. Statistical evaluation showed
a significant variation among the groups, with Group 2 exhibiting considerably lower
compressive strength than Groups 1 and 3.
Conclusion:Based on the findings, it can be concluded that immersion in sodium
hypochlorite significantly reduces the compressive strength of the tested material, whereas
microwave disinfection does not cause a notable decrease compared to the control.