Method: Cerium oxide (CeO2) was characterized by x-ray diffraction, particle size and FTIR. An experimental adhesive resin was formulated with 50% of BisGMA, 25% of TEGDMA and 25% of HEMA. Camphoroquinone and a tertiary amine were used as initiator system. To this blend were added different amounts of CeO2: 0; 0,36; 0,72; 1,44; 2,88; 4,32 and 5,76 vol%. The formulated adhesive resins were evaluated by degree of conversion, radiopacity and filler distribution by micro raman. Three samples of each group (n=3) was evaluated for the degree of conversion using FTIR. For radiopacity, five samples (n=5) of each group were evaluated using a digital system with phosphorous plates. One sample of each group used for radiopacity evaluation was used for the characterization of filler distribution into experimental adhesives. Data were analyzed by One-way ANOVA and Tukey, with a significant level of 5%.
Result: Particles used in this study presents a monoclinic crystalline phase with typical chemical groups and mean size of 15.57µm. Radiopacity increased with the increase of amount of CeO2. Groups with 4,32 and 5,76 vol% showed high radiopacity than other groups and groups with 1,44 and 2,88vol% showed higher radiopacity than group with no filler. The degree of conversion ranged from 47,90 to 61,51%. The groups with up to 1,44vol% showed no statistical difference to 0%. The particles of CeO2 were able to found dispersed into experimental adhesive resins in all groups.
Conclusion: Therefore CeO2 can be a promising alternative for polymer-based biomaterials.