Measurement of the transmitted-light through human upper incisors

The light transmission through the human upper incisors was examined using infrared and green laser light in vivo. Both light simultaneously illuminated the labial surface of the tooth crown and the transmitted-light through the tooth crown was collected from the palatal surface. The intensities of transmitted infrared light and the transmitted green light (TGL) were smaller when the lights were illuminated and collected from cervical area than incisal area. TGL with nonvital teeth was almost nil. The intensities of transmitted-light through tooth crown were considered to indicate the condition of the pulp and to be applicable to pulp diagnostic testing.