A study was performed to assess 13 different eye protection filters, glasses and shields, intended for use with dental material light curing procedures as a follow-up to a similar investigation in 2006. To assess the safety and efficiency, spectra of curing lamps and filters were measured using a spectroradiometric instrument and integrating sphere. Based on international guidelines, from the International Commission on Non-Ionising Radiation Protection for blue light exposure to the eyes, the “maximum permissible exposure time” (tmax) for the protection filters were calculated with high and low safety margins. The high safety margin risk estimation was based on transmission spectra of the filters, whereas the estimation for accepting a lower safety margin was based on the overlap between emission spectra of several different curing lamps with known emission and the transmission spectra of the filters. According to the high safety estimations, 7 of 13 products had acceptable filtering qualities. Low safety estimations increased the number of acceptable filters to 10. Eye hazards and associated diseases, suggested to be induced by UV radiation and/or blue light were discussed. UV and blue light could cause acute eye hazards, whereas increasing evidence suggests that blue light contributes to chronic diseases, such as cataracts and age-related macular degeneration. The use of eye protection with adequately low transmission properties (0,1 %) in the relevant wavelength range (390–525 nm) will eliminate or greatly reduce the risk of eye hazards when light curing dental materials.
Rätt skydd radar ögonen från skador av härdljus
Ellen M Bruzell, Terje Christensen and Bjørn Johnsen
Tandläkartidningen 2014; 106 (15): 60–68