Camphorquinone derivative (i.e. carboxylated camphorquinone) is used as visible-light photoinitiator in biomedical applications. It is also used in dentistry and is often used in conjunction with hydrogen donating amine.
Ratanajanchai, M.; Tanwilai, D.; Sunintaboon, P. Visible light-induced surfactant-free emulsion polymerization using camphorquinone/tertiary amine as the initiating system for the synthesis of amine-functionalized colloidal nanoparticles. J. Colloid Interface Sci. 2013, 409, 25-31.
Wessels, M.; Leyhausen, G.; Volk, J.; Geurtsen, W. Oxidative stress is responsible for genotoxicity of camphorquinone in primary human gingival fibroblasts. Clin.Oral.Invest. 2014, 18 (6), 1705-1710.