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VOLUME 8 , ISSUE 2 ( February, 2007 ) > List of Articles


Effectiveness of Second-generation Light-emitting Diode (LED) Light Curing Units

Fabrício Aulo Ogliari, Ulisses Bastos Campregher, Susana Maria Werner Samuel, Carmen Beatriz Borges Fortes, Alberth David Correa Medina, Fabricio Mezzomo Collares

Citation Information : Ogliari FA, Campregher UB, Samuel SM, Fortes CB, Medina AD, Collares FM. Effectiveness of Second-generation Light-emitting Diode (LED) Light Curing Units. J Contemp Dent Pract 2007; 8 (2):35-42.

DOI: 10.5005/jcdp-8-2-35

License: CC BY-NC 3.0

Published Online: 00-02-2007

Copyright Statement:  Copyright © 2007; Jaypee Brothers Medical Publishers (P) Ltd.



The purpose of this study was to evaluate the effectiveness of three commercially available light emitting diode (LED) light curing units (LCU) (Elipar FreeLight - 3M ESPE; UltraLume LED2 - Ultradent; and Single V - BioArt) for polymerizing Z250-A3 composite (3M ESPE) using Knoop hardness, polymerization depth, and flexural strength properties.

Methods and Materials

The XL 2500 (3M ESPE) LCU, which is a conventional halogen unit, was used as a control. In all cases the curing time was 20 seconds. Hardness was determined 24 hours after composite cure for 10 samples of 8 mm diameter and 2 mm height for each LCU tested. Samples were stored dry in a lightproof container prior to testing. The depth of cure of the composite was measured immediately after composite polymerization for each LCU using three samples 4 mm in diameter and 6 mm in height. Flexural strength was determined for five samples 24 hours after immersion in distilled water at 37°C. Each sample measured 25 mm in length, 2 mm in width, and 2 mm in height for each LCU tested.


The results were treated statistically for comparison of the LCUs. In all cases the results obtained by LED LCUs were not different or were higher than a conventional halogen LCU.

Clinical Significance

Second generation LED LCUs were as effective as/or more effective than a halogen LCU for polymerization of the used composite. The present study shows second generation LEDs have the potential to replace halogen LCUs.


Campregher UB, Samuel SMW, Fortes CBB, Medina ADC, Collares FMC, Ogliari FA. Effectiveness of Second-generation Light-emitting Diode (LED) Light Curing Units. J Contemp Dent Pract 2007 February;(8)2:035-042.

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