Tetraacylgermanes as highly efficient photoinitiators for visible light cured dimethacrylate resins and dental composites

Norbert Moszner*, Urs Karl Fischer, Iris Lamparth, Pascal Fässler, Judith Radebner, Anna Eibel, Michael Haas, Georg Gescheidt-Demner, Harald Stüger

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Tetrabenzoylgermane 1 and various substituted tetrabenzoylgermanes 2–7 were investigated as visible light (VL) photoinitiators (PIs) for dental dimethacrylate resins and dimethacrylate-based composites. The tetrabenzoylgermanes 1–7 show a very strong VL absorption between 400 and 450 nm. Substituents on the benzoyl chromophore strongly influence their properties such as melting point, solubility, absorption behavior, or PI reactivity. A good photobleaching behavior and a very high reactivity as VL PI was found in photo-differential scanning calorimeter experiments for selected tetrabenzoylgermanes. Composite pastes containing only ∼0.1 wt % of Ge-PI exhibited a sufficient photocuring due to the high PI-reactivity of the tetraacylgermanes. Among the investigated germane PIs, tetrakis(2-methylbenzoyl)germane 2 shows the best performance as VL PI for restorative composites and enables the composites to be photocured using an LED with an emission maximum of 500 nm
Original languageEnglish
Article number46115
JournalJournal of Applied Polymer Science
Issue number15
Publication statusPublished - 2018

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