Effect of ionizing radiation on the properties of restorative materials

The aim of this study is to evaluate the effect of different doses of the ionizing radiation (0 Gy, 10 Gy, 30 Gy, and 60 Gy) on the physical properties of dental materials.

Disc-shaped samples from each material (Ketac Molar Easymix, Vitro Molar, Vitremer, Vitro Fil Lc, Filtek Z 250 and Filtek Z 350) were made for water solubility, sorption analysis (n = 20), microhardness (n = 20), and surface roughness analysis (n = 24). Specimens were divided into four groups, according to radiation dose: control group (0 Gy), 10 Gy, 30 Gy, and 60 Gy. For water solubility and sorption analysis, the specimens were irradiated and were stored for 21 days to calculate the water solubility and sorption values. Microhardness analysis was carried out before and after irradiation doses. For surface roughness analysis, the specimens were submitted to brushing test, and after 24 h, initial surface roughness analysis was made in a rugosimeter. Subsequently, the samples were irradiated and final surface roughness analysis was made. The original water solubility and sorption, surface roughness, and microhardness values were subjected to ANOVA two-way statistical analysis and Paired t-test and Tukey post hoc test (α = 0.05), respectively.

Water solubility and sorption values, and surface roughness values presented statistical difference between groups (0, 10, 30 e 60 Gy) for all materials.

High doses of ionizing radiation (30 Gy and 60 Gy) increased the surface roughness, sorption, and solubility for the most materials.