utilized over a protracted time on each patient and many times during the day may very well cause optical difficulties especially for the dentist and also for an attending nurse or other bystanders in accordance with the invention therefore we have provided a means to mitigate the difficulty and having other advantages in the customary instance there is afforded a dental handpiece 6 of any convenient size and shape usually rectilinear for the most part and having a connection 7 to an appropriate light source not shown this source is ordinarily of high intensity and transmits very intense light to the handpiece 6 and through the handpiece by means of a fiber optic bundle or the like the handpiece 6 includes an extension 8 having a curvilinear configuration ending in a circular cylindrical tip 9 with a squared off end 11 in the usual practice the handpiece is brought into position with the tip 9 close to the subjacent surface of the tooth or material to be treated or polymerized under most circumstances a great deal of the light is scattered or escapes to the general surroundings in the present case there is fitted over the tip 9 a shield structure.