IADR Abstract Archives
Curing Light Outputs, Protocols and Composite Requirements at 422 Dental Offices
Objectives: This study examined light curing unit (LCU) outputs (mW/cm2) and curing protocols in dental offices to estimate the energy available (EA) in J/cm2 to cure the resin-based composites (RBC) used. The resulting EA for each LCU was compared to the RBC manufacturer’s minimum energy requirement (ER). Distance and operator technique variables were applied to estimate the energy reaching the RBC surface intra-orally.
Methods: The curing time, mode and LCU tip condition were recorded for 915 LCUs in 422 dental offices in 14 North American cities. LCU output was measured using a NIST-referenced spectrometer (checkMARC®, BlueLight Analytics). The EA at the LCU tip was calculated as power (mW)/LCU tip active area (cm2), multiplied by curing time (s) and number of curing cycles used. Ten LCU brands made up 55% of those tested. The LCUs were evaluated for their performance over clinically relevant distances, and the weighted percentage decrease in irradiance from 0 to 5 mm was measured and multiplied by the EA at the tip. EA was then reduced by another 32% to account for demonstrated variations in operator technique (JADA 2014;145:32-43).
Results: ER information was available for only 1,902 of the 2,250 LCU-RBC combinations. The range of EA at 0 mm distance was from 1.9 to 99.3 J/cm2. For 67% of LCU-RBC combinations, EA exceeded ER at 0 mm. At the clinically relevant distance of 5 mm, only 56% had sufficient EA, and this was further reduced to 34% of the combinations when operator technique variations were considered.
Conclusions: This comprehensive study includes data directly obtained from over 400 dental offices and shows that when LCU output, total curing time, clinical distance and operator technique are considered together, in only approximately one in three composite light-curing situations is the manufacturer’s recommended minimum required energy to adequately cure their composite material achieved.
Methods: The curing time, mode and LCU tip condition were recorded for 915 LCUs in 422 dental offices in 14 North American cities. LCU output was measured using a NIST-referenced spectrometer (checkMARC®, BlueLight Analytics). The EA at the LCU tip was calculated as power (mW)/LCU tip active area (cm2), multiplied by curing time (s) and number of curing cycles used. Ten LCU brands made up 55% of those tested. The LCUs were evaluated for their performance over clinically relevant distances, and the weighted percentage decrease in irradiance from 0 to 5 mm was measured and multiplied by the EA at the tip. EA was then reduced by another 32% to account for demonstrated variations in operator technique (JADA 2014;145:32-43).
Results: ER information was available for only 1,902 of the 2,250 LCU-RBC combinations. The range of EA at 0 mm distance was from 1.9 to 99.3 J/cm2. For 67% of LCU-RBC combinations, EA exceeded ER at 0 mm. At the clinically relevant distance of 5 mm, only 56% had sufficient EA, and this was further reduced to 34% of the combinations when operator technique variations were considered.
Conclusions: This comprehensive study includes data directly obtained from over 400 dental offices and shows that when LCU output, total curing time, clinical distance and operator technique are considered together, in only approximately one in three composite light-curing situations is the manufacturer’s recommended minimum required energy to adequately cure their composite material achieved.