Ricerc@Sapienza

Background: Shade matching is a significant treatment step and a challenge for the clinical team with potentially high costs for color correction. Currently, in the United States, the majority of private dental practitioners use visual color matching, but a recent study has reported a high rate of mistakes of subjective color determination among graduate dentists. Objective: The aim of this retrospective study is to analyze whether a change in the oral background due to dental occlusion can influence tooth color determination.

With a view to characterizing the influence of the electronic structure of the Fe atom on the nature of its bond with dioxygen (O-2) in heme compounds, a study of the UV/Vis action spectra and binding energies of heme-O-2 molecules has been undertaken in the gas phase. The binding reaction of protonated ferrous heme [Fe-II-hemeH](+) with O-2 has been studied in the gas phase by determining the equilibrium of complexed [Fe-II-hemeH(O-2)](+) with uncomplexed protonated heme in an ion trap at controlled temperatures.