Effect of Electron Beam Irradiation on Flexural Strength of Two Nanocomposites-an In vitro Study

Aim: The aim of this study is to investigate whether dental nanocomposite Filtek Z350 XT and Ceram X-duo can benefit from electron beam irradiation in order to achieve increased flexural strength
Place and Duration of Study: Department of Conservative Dentistry and Endodontics,
A. B. Shetty Memorial Institute of Dental Sciences, Nitte University, Deralakatte, Mangalore, India and Microtron Centre; Department of Physics Mangalore University; Mangalore, India between May 2011 to March 2014.
Materials and Methods: Materials were prepared on rectangular bar shaped specimens of 25-×2-×2-mm according to ISO standard -4049. Electron beam irradiation dose selected for the study were 1KGy, 3KGy and 5KGy. In total, 48 specimens were fabricated and divided into 4 groups based on radiation dose group I (non-radiated), group II (1KGy), group III (3KGy), group IV (5KGy) with 12 specimens in each. After 24 hours, specimens were subjected to 3-point bend test on a universal uniaxial servo mechanical testing machine.
Statistical Analysis: Performed using one way ANOVA and inter group comparisons were done using tukeys multiple comparision. ‘P’ value<0.05 was considered statistically significant.
Results: Flexural strength of Filtex Z350 XT before radiation was170.89±9.07.Flexural strength of Filtex Z350 XT after irradiation with 1KGy, 3KGy and 5KGy was found to be 269.06±94.91, 326.53±54.74 and 377.64±74.5 respectively. P value statistically significant (P<0.0001). Flexural strength of Ceram X duo before radiation was120.14±7.12.Flexural strength of Ceram X duo after irradiation with 1KGy, 3KGy and 5KGy was found to be 206.27±76.38, 177.31±67.35 and 229.33±59.15 respectively. P value statistically significant (P<0.0001).
Conclusion: It can be concluded that electron beam irradiation can be used as a tool to modify the present day dental materials for enhancing their mechanical properties.