Light-curing unit for effective polymerization of light-cured resins under nitrogen gas. Curing chamber is the ideal size for dental applications at 4.72" x 4.72" x 1.97" (120mm x 120mm x 50mm). Unit features 2 photo-flash lamps that produce 10 flashes/second with 200 watts of power in a spectral distribution from 280nm to 700nm. Because of this, the cured resin materials exhibit excellent physical properties and reduced residual monomer. Unit can be used with nitrogen to produce an inert environment, which prevents oxygen inhibition at the surface to produce an even higher quality product.