Use of a plaque light on the maxillary premolar teeth of a dog. Plaque fluoresces a bright pink color when the blue light is applied. This can be a training tool for owners to recognize the amount of plaque on the tooth surface. In addition, for owners who are diligent with home care, it can identify areas in which they could improve their brushing technique. Note that the image demonstrates the use of a plaque light to identify plaque, but it is overlying a heavy layer of calculus, which can only be removed by a professional.