Assessment of radiant exitance of light-curing units used in Dental Clinics in Benghazi, Libya

Aim: To evaluate the radiant exitance (RE) of light-curing units (LCUs) used in dental clinics and educational centers in Benghazi, Libya, and assess dentists’ knowledge of LCU usage. Materials and Methods: RE measurements of 180 LCUs from various dental clinics in Benghazi were obtained using a handheld dental radiometer. Data collected included: I) Device specifications (type [quartz-tungsten-halogen (QTH) or light-emitting diode (LED)], manufacturer, model, and version; II) Usage and maintenance history (clinical age, date of last use, and type of last maintenance of the LCU, III) Clinical practice parameters (exposure time per resin composite increment, tip size, presence of residual cured resin composite on the tips, and radiometer availability). Three measurements per LCU were taken, and the average was recorded as the RE value. The acceptable RE range was set between 300-1200 mW/cm2. Data were analyzed using SPSS with descriptive statistics. Results: LED LCUs were the most frequently used in the dental clinics (179, 99.4%), with only one QTH unit (0.6%). Woodpecker cordless models were the most common. Mean RE was 930.86 mW/cm2 (SD: 633; range: 0–3125 mW/cm²). Out of the 180 LCUs, 111 (61.7%) fell within the acceptable RE range, while 20 (11.1%) delivered insufficient RE (<300 mW/cm2) and 49 (27.2%) exceeded the upper limit (>1200 mW/cm²). Dentists exhibited limited knowledge of LCU functionality. Conclusions: Within the study’s limitations, the following conclusions were drawn: a) Great variations in RE performance among LCUs with clinically significant outliers, b) Majority were LED LCUs and operating within the acceptable RE range; c) The predominant LCU brand showed deficiencies in RE efficiency. Dentists’ knowledge regarding LCU functionality maintenance was limited.