Journal of Dental Research, Vol 66, 731-736, Copyright © 1987 by International & American Associations for Dental Research Online Journals
Potential retinal hazards of visible-light photopolymerization units
K. D. Satrom, M. A. Morris and L. P. Crigger
We evaluated the potential for retinal damage, both thermal and
photochemical, from commercially available visible-light
photopolymerization units. The spectral radiance profiles of 11
visible-light photopolymerization units were measured by means of a
spectroradiometer and the results weighted according to the American
Conference of Governmental Industrial Hygienists (ACGIH) Blue Light Hazard
Function and Thermal Hazard Function. The values were then integrated by
means of the proposed ACGIH hazard formulae, so that we could determine the
maximum permissible exposure (tMAX) duration for each light. This
calculation assumed a worst-case condition of direct vision of the light
source from a distance of 25 cm. The results indicate that there is no
thermal hazard to the retina. The tMAX duration values for the
photochemical (blue light) hazard to the retina ranged from 2.4 minutes per
day (for the most hazardous unit) to 16.0 minutes per day (for the least
hazardous). None of these hazard times is short enough to be of concern
unless the individual operator elects to focus on the light source or the
reflected output from these visible-light photopolymerization units for an
extended period of time.
