Water Absorption and Solubility of Fluoride-Based Restorative Materials Exposed to Ionizing Radiation

Radiotherapy is a key treatment for head and neck cancers but often compromises oral health, partly through its impact on restorative materials. A specific concern is whether ionizing radiation alters the water absorption and solubility of fluoride-releasing restoratives, potentially affecting their durability. This study aimed to evaluate these properties following clinically relevant radiation exposure.

Seven contemporary fluoride-releasing restorative materials (Fuji IX, Equia Forte HT, Fuji Triage, Activa Presto, Cention, Luminos, and Beautifil II) were tested (n = 10 per group). Specimens were either irradiated with 70 Gy in 35 fractions using a clinical linear accelerator or maintained as non-irradiated controls. Water absorption and solubility were measured over 35 days according to ISO 4049 protocols, and data were analyzed with repeated-measures ANOVA.

Across all materials, irradiated specimens exhibited slightly higher water absorption and solubility values compared to controls; however, differences were not statistically significant (p > 0.05). Material-specific trends were observed, with Fuji IX, Fuji Triage, Beautifil II, and Equia Forte showing relatively higher absolute values.

Clinically relevant ionizing radiation did not significantly affect the water absorption or solubility of the tested fluoride-releasing restorative materials, suggesting preserved physicochemical stability under therapeutic conditions.