Abstract from Ellen Bruzells lecture at symposium MED-10 Dentistry. (Organized by Ellen Bruzell). ESP-IUPB World Congress, Light & Life, Barcelona, Spain. August 25-30. 2019.

Dental personnel encounter a number of optical sources emitting a broad spectrum of wavelengths. Along with the usefulness, to various extents, of optical radiation in treatment and diagnostics, comes the risk of radiation exposure to the operator’s eyes and the patients’ oral tissues. The presentation will cover the “involuntary” and “voluntary” use of different light sources.  The curing light used for photopolymerisation of dental materials is an everyday procedure in the clinic. Curing lights have evolved from emitting moderate intensities of UV to high intensity blue light LEDs of several watts per centimeter squared.

Dental bleaching procedures combined with light is a controversial topic. It is debated whether the light improves the efficiency. Thereby, the justification of the use is questionable. The bleaching lights may emit UV or blue light or both in doses that can exceed limit values. The light sources are diverse: halogen, LED, and lasers among others.

Lasers are used in a wide variety of applications depending on their optical characteristics. Some laser procedures are established, the use of others are being debated, and some are under development.

PDT to treat infections and oral lesions is a recent treatment option, and the applications that are under development can use several light sources. PDT protocols vary greatly between e.g. photosensitiser type and application time, light sources, and light dose. Examples will be given from our research group’s use of formulated curcumin, lumichrome and porphyrins.

The use of light in dental diagnostics of caries and oral cancer could be a valuable tool, but is not used by most dentist. Imaging of bacterial infections and lesions may be an aid in e.g. experimental PDT and toxicology.

Finally, illumination sources are important for optimal viewing conditions for dental personnel. The operating lights have increased intensity compared to previous versions, and the use of lights on loupes and in microscopy have increased. Can it be too much light?