Development and application of an orthodontic near infrared photometer and thermometer

The paper describes the development, calibration and testing of a custom made photometric-thermometric sensor used to measure the penetration of NIR radiation from an intraoral therapeutic LED source, and the resultant temperature increase in tooth sockets. The difficulty of producing this novel device resides in its small dimensions. However a judicious choice of probes enabled successful development, calibration and in vivo testing. Apart from photometric and thermometric data the heart rate of the patients was also apparent, due to swelling of the capillaries in the gum tissue during systole — the contraction phase — of the cardiac cycle.