Irradiance
Pronunciation: ih-RAY-dee-ants
The radiant power per unit area delivered to a dental material's surface by a curing unit, expressed in milliwatts per square centimetre (mW/cm²).
Full Definition
Irradiance is a critical parameter in the polymerisation of light-cured dental materials, defining the intensity of light energy received per unit area of material surface from the curing unit tip. It is measured in mW/cm² and must be distinguished from radiant exposure (energy dose), which is the product of irradiance and exposure time, expressed in J/cm². Both values influence the degree of conversion achieved. Editors commonly encounter the incorrect use of 'intensity' in place of 'irradiance'; the correct physical quantity for reporting curing light output in dental research is irradiance. Radiometer readings should accompany experimental protocols.
Usage
Usage note: Do not substitute 'intensity' for 'irradiance' in formal manuscripts; irradiance is the correct radiometric term. Radiant exposure (J/cm²) is the dose; irradiance (mW/cm²) is the rate. Both must be reported in polymerisation studies.
In Context
- "The curing unit delivered an irradiance of 800 mW/cm² as verified by a calibrated dental radiometer." — Methods section, depth-of-cure experiment
- "The author wrote 'light intensity' throughout; the editor replaced each instance with 'irradiance' in accordance with ISO 10650 nomenclature." — Editorial revision note, biomedical engineering journal