head JofIMAB
Journal of IMAB - Annual Proceeding (Scientific Papers)
Publisher: Peytchinski Publishing Ltd.
ISSN: 1312-773X (Online)
Issue: 2021, vol. 27, issue4
Subject Area: Dental Medicine
DOI: 10.5272/jimab.2021274.4164
Published online: 15 December 2021

Original article

J of IMAB. 2021 Oct-Dec;27(4):4164-4169
Georgi Georgiev1ORCID logo Corresponding Autoremail, Tsanka Dikova2ORCID logo, Vladimir Panov1ORCID logo,
1) Department of Conservative Dentistry and Oral Pathology, Faculty of Dental Medicine, Medical University of Varna, Bulgaria.
2) Department of Dental Materials Science and Propaedeutics of Prosthetic Dental Medicine, Faculty of Dental Medicine, Medical University of Varna, Bulgaria.

Quartz-tungsten halogen light curing units (LCUs) have been the main source of light for the polymerization of resin based composites (RBCs) for several decades. Since the beginning of the 20th century, however, their use has been reduced due to the invention and improvement of LED LCUs. Various factors can cause a decrease in the light intensity of LED LCUs, one of which is diode aging. The aim of the present paper is to study the change in light intensity of LCUs after different periods of intensive use. For this purpose, the light intensity of 94 regularly used LED LCUs aged between 1 and 10 years was measured with a digital radiometer. The devices were used in conventional mode with maximum light intensity. It was found that regardless of the type and model of LCU, there is a direct relationship between the time of use and light intensity - the longer the operation period of a device is and the more used it is, the lower its intensity is. The decrease in light intensity as devices age is different for different models, as well as for different devices of the same model. In the studied LCUs with a 10-year period of use, 77.5% have light intensity lower than the required minimum of 400 mW/cm2, which makes them unusable. It can be concluded that dentists should regularly monitor and measure the light intensity of their LCUs, especially as they age, to ensure the longevity of their restorative procedures.

Keywords: light curing units, LED, light intensity, period of use,

pdf - Download FULL TEXT /PDF 1002 KB/
Please cite this article as: Georgiev G, Dikova T, Panov V. Investigation of light intensity of light curing units after different periods of use. J of IMAB. 2021 Oct-Dec;27(4):4164-4169.
DOI: 10.5272/jimab.2021274.4164

Corresponding AutorCorrespondence to: Georgi Georgiev, Department of Conservative Dentistry and Oral Pathology, Faculty of Dental Medicine, Medical University of Varna; 84, Tsar Osvoboditel Blvd, 9000 Varna, Bulgaria; E-mail: dr_g_georgiev88@abv.bg

1. Domejean S, Leger S, Maltrait M, Espelid I, Tveit AB, Tubert-Jeannin S. Changes in occlusal caries lesion management in France from 2002 to 2012: a persistent gap between evidence and clinical practice. Caries Res. 2015 Jun;49(4):408-16. [PubMed]
2. Eklund SA. Trends in dental treatment, 1992 to 2007. J Am Dent Assoc. 2010 Apr;141(4):391-9. [PubMed]
3. Lynch CD, McConnell RJ, Wilson NH. Trends in the placement of posterior composites in dental schools. J Dent Educ. 2007 Mar;71(3):430-434. [PubMed]
4. Opdam NJ, Bronkhorst E, Roeters J, Loomans BA. Longevity and reasons for failure of sandwich and total-etch posterior composite resin restorations. J Adhes Dent. 2007 Oct;9(5):469-75. [PubMed]
5. Imazato S, McCabe JF, Tarumi H, Ehara A, Ebisu S. Degree of conversion of composites measured by DTA and FTIR. Dent Mater. 2001 Mar;17(2):178-83. [PubMed]
6. Peutzfeldt A, Sahafi A, Asmussen E. Characterization of resin composites polymerized with plasma arc curing units. Dent Mater. 2000 Sep;16(5):330-6. [PubMed]
7. Ruyter I, Svendsen SA. Remaining methacrylate groups in composite restorative materials. Acta Odontol Scand. 1978;36(2):75-82. [PubMed]
8. Indzhov B. [Obturatio cavi dentis.] [in Bulgarian] 7print, Sofia. 2009. Chapter 2, p.19-34.
9. Krifka S, Seidenader C, Hiller KA, Schmalz G, Schweikl H. Oxidative stress and cytotoxicity generated by dental composites in human pulp cells. Clin Oral Invest. 2012 Feb;16(1):215-24. [PubMed]
10. Chen YC, Ferracane JL, Prahl SA. Quantum yield of conversion of the photoinitiator camphorquinone. Dent Mater. 2007 Jun;23(6):655-64. [PubMed]
11. Al-Ahdal K, Ilie N, Silikas N, Watts D.C. Polymerization kinetics and impact of post polymerization on the degree of conversion of bulk-fill resin-composite at clinically relevant depth. Dent Mater. 2015 Oct;31(10):1207-13. [PubMed]
12. Rueggeberg FA, Caughman WF, Curtis JW, Jr. Effect of light intensity and exposure duration on cure of resin composite. Oper Dent. 1994 Jan-Feb;19(1):26-32. [PubMed]
13. Kofford KR, Wakefield CW, Nunn ME. The effect of autoclaving and polishing techniques on energy transmission of light-curing tips. Quintessence Int. 1998 Aug;29(8):491-6. [PubMed]
14. Dugan WT, Hartleb JH. Influence of a glutaraldehyde disinfecting solution on curing light effectiveness. Gen Dent. 1989 Jan-Feb;37(1):40-3. [PubMed]
15. Tongtaksin A, Leevailoj C. Battery charge affects the stability of light intensity from lightemitting diode light-curing units. Oper Dent. 2017 Sep-Oct;42(5), 497-504. [PubMed]
16. Georgiev G, Panov V, Dikova T. Investigation of light intensity of wireless LED light curing units. J Techn Univ Gabrovo. 2020; 60:40-45.
17. Barghi N, Berry T, Hatton C. Evaluating intensity output of curing lights in private dental offices. J Am Dent Assoc. 1994 Jul;125(7):992–6. [PubMed]
18. Martin FE. A survey of the efficiency of visible light curing units.& J Dent. 1998 Mar;26(3):239–43. [PubMed]
19. Poulos JG, Styner DL. Curing lights: changes in intensity output with use over time. Gen Dent. 1997 Jan-Feb;45(1):70–3. [PubMed]
20. Friedman J, Hassan R. Comparison study of visible curing lights and hardness of light-cured restorative materials. J Prosthet Dent. 1984 Oct;52(4):504–6. [PubMed]
21. Omidi B, Gosili A, Jaber-Ansari M, Mahdkhah A. Intensity output and effectiveness of light curing units in dental offices J Clin Exp Dent. 2018 Jun;10(6):e555–e560. [PubMed]
22. Miyazaki M, Hattori T, Ichiishi Y, Kondo M, Onose H, Moore BK. Evaluation of curing units used in private dental offices. Oper Dent. 1998 Mar-Apr;23(2):50-4. [PubMed]
23. Barghi N, Fischer DE, Pham T. Revisiting the intensity output of curing lights in private dental offices. Compend Contin Educ Dent. 2007 Jul;28(7):380–4,quiz 385-6. [PubMed]
24. Georgiev G. Factors associated with light curing units: a questionnaire survey. Scr Sci Med Dent. 2019;5(2):37-43. [Crossref].

Received: 28 May 2021
Published online: 15 December 2021

back to Online Journal