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Albumin is a salivary enzyme capable of cleaving ester linkages and catalyzing degradation of resinbased dental materials. However, the effect of concentration-dependent esterolytic action on composite resins as yet remains unexplored. Aim: The purpose of this study was to evaluate whether artificial saliva formulations with different concentrations of albumin affected the surface roughness, flexural strength and microhardness of a composite resin. Materials and Method: Specimens (25x2x2mm) of a nanofilled composite (Filtek Z350XT, 3M/ESPE) were prepared and analyzed for average surface roughness (Ra/µm). The specimens were then allocated to 6 groups (n=30), to be treated with different salivary albumin concentrations: 0, 10, 50, 100, 200, 400 µg/mL. The specimens were stored in their respective artificial saliva groups, half of them for 24 h and the remainder for 180 days (artificial saliva renewed weekly), after which they were submitted to a new Ra reading, and tested for three-point flexural strength (FS, MPa). The specimens stored for 180 days were analyzed for Knoop microhardness (KH, Kg/mm2 ). Data were submitted to two-way ANOVA (Ra and FS) and one-way ANOVA (KH). Results: Although Ra increased (p < 0.001) and FS decreased (p < 0.001) from 24 hours to 180 days of storage, the albumin concentration did not significantly affect Ra (p = 0.168), FS (p = 0.477) or KH (p = 0.378). Conclusion: The esterolytic action of albumin did not increase the artificial-saliva-induced hydrolytic degradation of the composite resin.

The title chalcone derivative, C15H10F2O, is almost planar, with the benzene ring being inclined to the phenyl ring by 7.45 (9)°. The conformation about the C=C bond isE. In the crystal, molecules are linked by two pairs of C—H...F hydrogen bonds, forming inversion dimers enclosingR22(8) andR21(10) ring motifs. The dimers stack along theaaxis with the separation of the C=C bonds being 4.2926 (4) Å.