Product: Eye protection filters for use with curing lamps
Test methods: Light transmittance measurement
Requirements: Less than 0.1% light transmittance in the wavelength region 390–525 nm
Light transmittance measurement:
The filter is irradiated polychromatically by a 100 W Xenon lamp fitted with collimating optics. The flux entering and passing the filter material is collected by an integrating sphere, connected to a high-resolution double-monochromator spectroradiometer. Measurements are made for the wavelength range 250 nm to 800 nm (optionally 1000 nm). The transmittance spectrum is calculated as the ratio between the spectrum entering and passing the filter material. Irradiance calibrations are traceable to Physikalisch-Technische Bundesanstalt, Braunschweig, Germany (PTB) via Physikalisch-Meteorologisches Observatorium Davos – World Radiation Center, Switzerland (PMOD-WRC).
Requirements for transmittance of eye protection filters against light emission from dental curing lamps. The transmittance of an eye protective filter must be less than 0.1% within the wavelength interval 390–525 nm.
To determine whether the filter in question is suitable to protect against direct and/or reflected light from dental curing lamps, the maximum permissible exposure time will be estimated according to ICNIRP (International Commission on Non-Ionizing Radiation Protection): Guidelines on limits of exposure to incoherent visible and infrared radiation, Health Physics 2013; 105 (1): 74–96.
The estimation procedure is described in:
Bruzell E, Johnsen B, Aalerud TN, Dahl JE, Christensen T. In vitro efficacy and risk for adverse effects of light-assisted tooth bleaching. Photochem and Photobiol Sci 2009; 8: 377–85.