In a dental system for the transillumination of teeth having an elongate handpiece with a light source for producing examination radiation, irradiation means for directing the examination radiation at a tooth to be examined, and means for acquiring an optical image of the tooth illuminated by the examination radiation, there is arranged at the front end of the handpiece a removable attachment which contains at least part of the irradiation means, the handpiece having means for detecting the attachment arranged on the handpiece.