Curing efficiency of high-intensity light-emitting diode (LED) devices

Area of Science:

• Dental Materials Science
• Polymer Chemistry
• Biomaterials Engineering

Background:

• Light-curing is crucial for dental resin polymerization.
• High-intensity light-emitting diode (LED) devices offer advantages over traditional quartz-tungsten-halogen (QTH) lights.
• Evaluating the curing efficiency of different LED devices is essential for clinical success.

Purpose of the Study:

• To compare the curing efficiency of four high-intensity LED light-curing units against a QTH control.
• To assess key parameters including residual double bond percentage (%RDB), surface microhardness (SM), depth of cure (DC), linear shrinkage-strain (%LS), and wall-to-wall contraction (%WWC).

Main Methods:

• Four LED devices (Allegro, Bluephase, FreeLight2, The Cure TC-01) and one QTH light were tested.
• %RDB was measured using microFTIR spectroscopy.
• Microhardness was assessed at various depths (H0, H3, H5) to determine DC.
• %LS was evaluated using the bonded disc method.
• %WWC was quantified using micro-CT imaging.

Main Results:

• No significant differences were found among LED devices for %RDB or %LS.
• The Bluephase and Allegro LEDs demonstrated the highest SM values.
• Bluephase and The Cure TC-01 showed lower depth of cure at 3 mm and 5 mm compared to other LEDs.
• %WWC did not differ significantly among LEDs, with QTH exhibiting the lowest %WWC.

Conclusions:

• LED devices exhibit comparable performance in %RDB and %LS, but vary in SM and DC.
• Clinical selection of LED curing units should consider their specific performance characteristics.
• Further research may explore long-term clinical performance and material interactions.