The Open Dentistry Journal

ISSN: 1874-2106 ― Volume 14, 2020

Effect of Contamination, Damage and Barriers on the Light Output of Light-Curing Units

Abdulhaq A. Suliman1, *, Ahmad A. Abdo1, Hussein A. Elmasmari1
1 Unit of Restorative Dentistry, College of Dentistry, Ajman University, Ajman, UAE



Light-curing is a crucial step during the application of composite resin restorations. The clinical success of composite depends on the Light-Curing Units (LCU) to deliver adequate light energy to polymerize the resin. However, light-curing usually does not receive the proper awareness it deserves.


This study aims to evaluate the effect of contamination and debris of the LCU’s tip on its light output. Determine the effect of damage to the LCU’s tip such as chipping, dents and scratches. Additionally, it evaluates the effect of plastic barrier sleeves.


Sixty LED LCUs were tested using MARC™ Resin Calibrator (BlueLight Analytic Inc., Halifax, Canada) to measure their irradiance and energy before and after cleaning their tips. They were also tested with and without a clear plastic barrier. Additionally, four damaged LCUs received new tips and were tested again. Kruskal-Wallis H and One-Way ANOVA tests were used for statistical analysis.


Cleaning the LCUs’ tips showed significant improvement, an average increase of 8.2%. However, some units increased by up to 47% in irradiance and energy values. Replacing the damaged tip with a new one significantly improved the output of the LCUs, increasing light energy by up to 73%. The barrier used in this study caused 7% reduction in the energy delivered by the LCUs. The statistical analysis showed that cleaning the LCUs and replacing their damaged tips resulted in a significant increase in energy (p<0.05).


Unclean or damaged LCUs’ tips can drastically reduce the light output of the LCUs, reducing the quality of the composite restorations. Clinicians are strongly recommended to regularly monitor, clean and maintain their curing lights.

Keywords: Light-curing, Composite resins, Curing lights, Polymerization, Irradiance, Energy.

Article Information

Identifiers and Pagination:

Year: 2019
Volume: 13
First Page: 196
Last Page: 202
Publisher Id: TODENTJ-13-196
DOI: 10.2174/1874210601913010196

Article History:

Received Date: 07/04/2019
Revision Received Date: 12/05/2019
Acceptance Date: 03/06/2019
Electronic publication date: 30/06/2019
Collection year: 2019

© 2019 Suliman et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: ( This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Unit of Restorative Dentistry, College of Dentistry, Ajman University, Ajman, UAE, Tel: +971 6 705 6215 / +971 50 898 6334, Email:

Track Your Manuscript:


"Thank you for your magnificent and marvelous support throughout the publication stages. I would like to endorse my experience with you as a Junior Researcher and a recent graduate of the Dental school. Once again Thank you for your Great Help and Guidance throughout the stages of Publication. You guys are a great team and I am proud to be a Young Bentham author."

Asra Sabir Hussain
The University of Edinburgh Business School, UK

"My experience with Bentham Open was a valuable one because the quality of the services and analysis of my paper contributed in improving what we intended to convey to the readers."

José Ricardo Kina
Department of Surgery and Integrated Clinic,
Araçatuba School of Dentistry, São Paulo State University

"The Publication Manager was very cooperative and replied my mails and guided me without any delays; however the reviewing process was too long."

Mahtab Memarpour
Prevention of Oral and Dental Disease Research Center,
Department of Pediatric Dentistry, School of Dentistry,
Shiraz University of Medical Sciences, Shiraz,

Browse Contents

Webmaster Contact:
Copyright © 2020 Bentham Open