Advances in light curing

Purpose: To review and connect the scientific background of light curing wi th clinical requirements and new technical opportunities in order to conclu de the best technology for next generation light curing units. Results: Thr ee conclusions are drawn for proper light curing: (1) A minimum dose of lig ht is needed (wavelength dependent); (2) Internal stress can be reduced by giving the sample time to flow before gel point is reached; (3) An upper in tensity limit has to be respected to limit temperature increase as well as light intensity dependent deactivation of activated photoinitiators. These conclusions can best be realized by using the softstart approach. A compari son of different light generation technologies shows that LEDs are most lik ely to shape the next generations of curing lights. Due to their superior p ower conversion rate as well as to their optimum spectral emission small an d handy devices can be realized that work battery-powered and totally silen t. The benefits for the dentist are improved reliability, handling, and hyg iene.