Current photo-initiators in dental materials

Light induced reactions are based on the absorption of light that excites the electrons of a molecule and can, under favorable circumstances, lead to dissociation, isomerization, abstraction, electron or energy transfer, and bond formation. The most commonly used initiating system for photopolymerizable dental implants is a Type II PI consisting of camphorquinone (CQ) and ethyl 4-dimethylaminobenzoate (DMAB). However, this bimolecular PI-system exhibits numerous significant drawbacks such as low reactivity and stability, especially in water-based formulations. The demand for an appropriate PI for visible light curing is high for dental restoratives. This paper reviews the options of new photoinitiators for restorative materials.