Comparison of Blue Light Blocking Effects of Tips and Tinted Lenses for Dental Light Curing Machines

Background/Objectives: This study aimed to examine the blue-light blocking effect according to the curing light tip and the color of the protective eyeglass lens for the operator’s eye protection.

Method/Statistical Analysis: The transmittance of light with a wavelength between 200 and 900 nm was measured three times at 1.8 nm intervals using a UV-vis spectrophotometer (LAMBDA 265, Perkinelmer, Inc.). Then the average values obtained were compared for analysis. The visible- and blue-light transmittances of all the tips and tinted lenses were examined, and the ratios of blue light in the transmitted visible light were analyzed to compare the blue-light blocking effects.

Findings: The transmittance of visible light with a wavelength between 380 and 750 nm was highest in the yellow lens (60.58%), followed by company B’s tip (55.23%), company A’s tip (51.46%), the orange lens (47.48%), company C’s tip (41.53%), and the red lens (41.00%). The blue-light transmittance was 0.14% in company A’s tip for the curing light gun, 0.75% in company B’s tip, and 0.12% in company C’s tip, which were all very low. Among the tinted lenses, the orange lens had the lowest blue-light transmittance (0.20%), the red lens had a blue-light transmittance of 6.59%, and the yellow lens had the highest blue-light transmittance (12.53%). For the analysis results of the ratio of blue light in the transmitted visible light, it was 0.27% for company A’s tip, the best blue-light blocking rate, and 20.68% for the yellow lens, the worst blue-light blocking rate. The ratios of blue light in the transmitted visible light for companies B and C’s tips were 1.35 and 0.29%, respectively, showing that they have a good blue-light blocking effect.

Improvements/Applications: The curing light tips and orange lens used for the analyses in this study showed a blue-light blocking effect. In the case of blue-light blocking by tinted lenses, further studies are required because the blocking rate may vary depending on the lens tint concentration.