The purpose of this study was to determine the uptake of fluoride by dentin after pulsed Nd:YAG laser irradiation. Under SEM examination dentin lased by pulsed Nd:YAG laser appeared to be melted; there were no changes of calcium and phosphorus levels. Dentin irradiated by pulsed Nd:YAG laser and treated with 38% Ag(NH3)2F showed greater uptake and deep penetration of fluoride than topical application of fluoride alone, SEM examination revealed that CaF2-like and Ag3PO4-like deposits were formed on the dentin surface. These results suggested that pulsed Nd:YAG laser irradition could improve the absorption of fluoride in dentin.