1. A dental apparatus, comprising: a light irradiation unit for emitting a near-infrared light to irradiate an oral cavity; an image capturing unit for image-capturing the oral cavity light irradiated by the light irradiation unit; and an output unit programmed to output data for highlighting and displaying that discerns between a plaque site and a calculus site on an image of the oral cavity based on a reflected light amount from an image captured result by the image capturing unit.