A dental restorative composite and a method of curing the composite are disclosed in which the composite includes a polymerizable organic resin, a radiation activated initiator having an activation wavelength, an inert filler； and luminescent crystals, wherein the luminescent crystals emit radiation at a predetermined wavelength matching the initiator activation wavelength when the luminescent crystals are irradiated with radiation having a wavelength longer than the activation wavelength, the luminescent crystals being up-converting particles that result in those particles emitting radiation at a wavelength that initiates curing.
