ABSTRACT

Background: The daily and repeated immersion of dentures in disinfectant solutions can cause changes in the properties of PMMA, but there is lack of studies evaluating the effects of hydrogen peroxide disinfectant solution on CAD/CAM based Polymethylmethacrylate (PMMA).

Aim: To investigate the effect of hydrogen peroxide solution immersion on various properties (transverse strength, impact strength and surface hardness) of CAD/CAM based polymethylmethacrylate (PMMA).

Methods: 90 samples were prepared in this study. Samples were divided into 3 groups according to the type of the test used (transverse strength, impact strength, hardness), For each test 30 samples were further subdivided into ten samples for each of the three groups according to the type of treatment, 1st group control, 2nd group immersed in 3% hydrogen peroxide solution for 10 minutes, 3rd group immersed in 3% hydrogen peroxide solution for 30 minutes. Specimens in each group were subjected to the three-point bending test for transverse strength test, impact strength test and Surface hardness using shore D hardness tester. Scanning electron microscope (SEM). Statistical analysis was performed using two-way ANOVA and the data was considered statistically significant at a level of< 0.05.

Results: Statistical analysis of transverse strength test using two-way ANOVA showed non-significant increases in the mean value of the transverse strength for both immersion times, while a non-significant decrease of impact strength was found for both immersion times. Statistical analysis of Surface hardness test showed a non-significant decrease in the Mean value of the Surface hardness for 30 minutes immersion time and a non-significant increase for the 10 minutes immersion time. Conclusions: CAD/CAM based polymethylmethacrylate (PMMA) Immersion in 3% hydrogen peroxide solution showed no significant effect and changes in the mechanical properties of the material specifically transverse strength, impact strength and surface hardness.

Keywords: CAD/CAM, disinfection, impact strength, transverse strength.