IADR Abstract Archives
Curing Light Output Specifications Compared to Measured Output at 439 Dental Offices
Objectives: Studies have reported on suspected low outputs from light curing units (LCUs) in dental offices, but without regard to manufacturer’s stated specifications for the light, tip size, and curing regimen. This study measured irradiance (mW/cm2) coupled with curing protocols used for 946 LCUs in 439 dental offices from 14 North American cities to calculate total energy deliverable clinically, compared to the manufacturer stated specifications.
Methods: LCU output was measured using a NIST-referenced spectrometer (checkMARC®, BlueLight Analytics). The energy at the LCU tip was calculated as power (mW)/measured LCU tip active area (cm2), multiplied by curing time (s) and number of curing cycles used. The variance was calculated for the 735 LCUs where the manufacturer output specification was obtainable, with omissions being primarily older LCUs (10+ years) where documentation was unavailable.
Results: Irradiance of the LCUs ranged from 86 to 12,578 mW/cm2 (mean = 1050±550 mW/cm2). When incorporating the dentists’ curing protocols, the range of energy available at the light tip averaged 18±11 J/cm2, but was highly variable with more than 30% of the curing schemes delivering less than 12 J/cm2 and about 20% delivering more than 24 J/cm2 (Figure). For 184 LCUs, the output was >20% below specification, with the lowest being -91%. 111 LCUs measured >20% above specification, with the maximum being +91% over specification. The output of more than 40% of LCUs was more than ± >20% of specification.
Conclusions: Some LCUs perform well above specification, while others perform well below, due to damage, debris and/or light source degradation. This study demonstrates the wide variability in light curing applications performed by dentists in their practices, and emphasizes the need to accurately measure one’s curing light output in order to provide the appropriate energy to adequately cure resin-based dental materials, without producing excessive heat in the tooth.
Methods: LCU output was measured using a NIST-referenced spectrometer (checkMARC®, BlueLight Analytics). The energy at the LCU tip was calculated as power (mW)/measured LCU tip active area (cm2), multiplied by curing time (s) and number of curing cycles used. The variance was calculated for the 735 LCUs where the manufacturer output specification was obtainable, with omissions being primarily older LCUs (10+ years) where documentation was unavailable.
Results: Irradiance of the LCUs ranged from 86 to 12,578 mW/cm2 (mean = 1050±550 mW/cm2). When incorporating the dentists’ curing protocols, the range of energy available at the light tip averaged 18±11 J/cm2, but was highly variable with more than 30% of the curing schemes delivering less than 12 J/cm2 and about 20% delivering more than 24 J/cm2 (Figure). For 184 LCUs, the output was >20% below specification, with the lowest being -91%. 111 LCUs measured >20% above specification, with the maximum being +91% over specification. The output of more than 40% of LCUs was more than ± >20% of specification.
Conclusions: Some LCUs perform well above specification, while others perform well below, due to damage, debris and/or light source degradation. This study demonstrates the wide variability in light curing applications performed by dentists in their practices, and emphasizes the need to accurately measure one’s curing light output in order to provide the appropriate energy to adequately cure resin-based dental materials, without producing excessive heat in the tooth.
2120917_File000001.jpg