Distance Dependent Depth of Cure of a New Curing Light

Objectives: The aim of this study was to evaluate the curing performance of a prototype LED curing light as compared to commercially available devices by means of depth of cure (DOC) measurements. Previous studies showed a pronounced decrease in the curing performance with many common lights if the light guide was not in direct contact to the composite. Therefore, we tested the DOC not only at zero distance between light guide and composite material but also at a distance of 7mm.

Methods: DOC was measured according to ISO 4049 with the following devices: Bluephase (B, Ivoclar/Vivadent), Demi (D, Kerr), Elipar FreeLight 2 (E, 3M ESPE) and the prototype (P) of a new curing light. With each device and both distances, 7 samples of composite material (Filtek Supreme A2 body shade, 3M ESPE) were cured with a curing time of 10 seconds. The mean DOC values were compared and tested by one-way ANOVA (p<0.05).

Results: At zero distance the following means of the DOC values were found (units in mm, SD in brackets): B: 2.50 (0.03); D: 2.45 (0.01); E: 2.47 (0.03); P: 2.71 (0.04). The DOC value for P was significantly higher as compared to the others. The results with 7mm distance were: B: 1.90 (0.01); D: 2.08 (0.03); E: 1.95 (0.03); P: 2.27 (0.05). D was significantly higher than B and E. P was significantly higher than all other values at 7mm.

Conclusions: With the depth of cure measurements of this study, the new LED curing light showed the highest curing performance at zero as well as at a clinically relevant distance of 7mm.