Light-emitting diode (LED) polymerisation of dental composites: flexural properties and polymerisation potential

Area of Science:

• Dental Materials Science
• Polymer Chemistry
• Biomaterials Engineering

Background:

• Light-curing units (LCUs) significantly impact dental composite performance.
• Traditional halogen LCUs degrade over time, potentially compromising composite polymerization.
• Blue-light-emitting diode (LED) LCUs offer an alternative with potential advantages over halogen systems.

Purpose of the Study:

• To evaluate the flexural properties of dental composites polymerized by halogen versus LED LCUs.
• To investigate the curing effectiveness of LED LCUs compared to conventional halogen LCUs.
• To explore a model for predicting LCU curing effectiveness based on spectral properties.

Main Methods:

• Three dental composites in different shades were polymerized using a halogen LCU and an LED LCU.
• Flexural strength and flexural modulus were measured for all polymerized samples.
• A model correlating LCU emission spectra with camphorquinone absorption spectra was developed.

Main Results:

• No significant differences in flexural strength or modulus were observed between composites polymerized with halogen or LED LCUs in most cases.
• The study presents a model for assessing curing effectiveness based on spectral overlap.
• LED LCUs demonstrated comparable efficiency to halogen LCUs despite lower irradiance.

Conclusions:

• LED LCUs can effectively polymerize dental composites, yielding comparable flexural properties to those achieved with halogen LCUs.
• The spectral overlap model provides a basis for understanding and predicting LCU performance.
• LED LCUs represent a promising alternative to halogen LCUs in dental restorative procedures.