J Korean Acad Conserv Dent.  2011 Mar;36(2):108-113. 10.5395/JKACD.2011.36.2.108.

Effect of the difference in spectral outputs of the single and dual-peak LEDs on the microhardness and the color stability of resin composites

  • 1Department of Conservative Dentistry, Pusan National University School of Dentistry, Yangsan, Korea. jeongkil@pusan.ac.kr
  • 2Department of Dental Materials, Pusan National University School of Dentistry and Medical Research Institute, Yangsan, Korea.


To determine the effect of the spectral output of single and dual-peak light emitting diode (LED) curing lights on the microhardness and color stability of commercial resin composites formulated with camphorquinone and alternative photoinitiators in combination.
Three light-polymerized resin composites (Z100 (3M ESPE), Tetric Ceram (Ivoclar Vivadent) and Aelite LS Posterior (Bisco)) with different photoinitiator systems were used. The resin composites were packed into a Teflon mold (8 mm diameter and 2 mm thickness) on a cover glass. After packing the composites, they were light cured with single-peak and dual-peak LEDs. The Knoop microhardness (KHN) and color difference (DeltaE) for 30 days were measured. The data was analyzed statistically using a student's t-test (p < 0.05).
All resin composites showed improved microhardness when a third-generation dual-peak LED light was used. The color stability was also higher for all resin composites with dual-peak LEDs. However, there was a significant difference only for Aelite LS Posterior.
The dual-peak LEDs have a beneficial effect on the microhardness and color stability of resin composites formulated with a combination of camphorquinone and alternative photoinitiators.


Alternative photoinitiators; Camphorquinone; Color stability; Dual-peak light emitting diode (LED); Microhardness; Spectral outputs

MeSH Terms

Composite Resins
Enzyme Multiplied Immunoassay Technique
Composite Resins

Cited by  1 articles

Optimal combination of 3-component photoinitiation system to increase the degree of conversion of resin monomers
Chang-Gyu Kim, Ho-Jin Moon, Dong-Hoon Shin
J Korean Acad Conserv Dent. 2011;36(4):313-323.    doi: 10.5395/JKACD.2011.36.4.313.


1. Fan PL, Schumacher RM, Azzolin K, Geary R, Eichmiller FC. Curing-light intensity and depth of cure of resin-based composites tested according to international standards. J Am Dent Assoc. 2002. 133:429–434.
2. Yap AU, Soh MS, Han TT, Siow KS. Influence of curing lights and modes on cross-link density of dental composites. Oper Dent. 2004. 29:410–415.
3. Park YJ, Chae KH, Rawls HR. Development of a new photoinitiation system for dental light-cure composite resins. Dent Mater. 1999. 15:120–127.
4. Tak HS, Park SJ. Influences of camphoroquinone on the properties of composites. J Korean Acad Conserv Dent. 2001. 26:41–50.
5. Neumann MG, Schmitt CC, Ferreira GC, Corrêa IC. The initiating radical yields and the efficiency of polymerization for various dental photoinitiators excited by different light curing units. Dent Mater. 2006. 22:576–584.
6. Burtscher P, Rheinberger V. Efficiency of various light initiators after curing with different light-curing units. J Dent Res. 2003. Abstract #0042.
7. Neumann MG, Miranda WG Jr, Schmitt CC, Rueggeberg FA, Correa IC. Molar extinction coefficients and the photon absorption efficiency of dental photoinitiators and light curing units. J Dent. 2005. 33:525–532.
8. de Souza Costa CA, Hebling J, Hanks CT. Effects of light-curing time on the cytotoxicity of a restorative resin composite applied to an immortalized odontoblast-cell line. Oper Dent. 2003. 28:365–370.
9. Imazato S, Tarumi H, Kobayashi K, Hiraguri H, Oda K, Tsuchitani Y. Relationship between the degree of conversion and internal discoloration of light-activated composite. Dent Mater J. 1995. 14:23–30.
10. Roh BD, Park SH, Lee CS. An experimental study of the degree of conversion and cytotoxicity of dual cure resin cements. J Korean Acad Conserv Dent. 1995. 20:33–53.
11. Ferracane JL. Correlation between hardness and degree of conversion during the setting reaction of unfilled dental restorative resins. Dent Mater. 1985. 1:11–14.
12. Asmussen E. An accelerated test for color stability of restorative resins. Acta Odontol Scand. 1981. 39:329–332.
13. Cho YG, Kim MC. Color changes in composites according to various light curing sources. J Korean Acad Conserv Dent. 2002. 27:87–94.
14. Uhl A, Sigusch BW, Jandt KD. Second generation LEDs for the polymerization of oral biomaterials. Dent Mater. 2004. 20:80–87.
15. Price RB, Felix CA, Andreou P. Third-generation vs a second-generation LED curing light: effect on Knoop microhardness. Compend Contin Educ Dent. 2006. 27:490–496.
16. Price RB, Felix CA, Andreou P. Evaluation of a dual peak third generation LED curing light. Compend Contin Educ Dent. 2005. 26:331–332.
17. Schneider LF, Pfeifer CS, Consani S, Prahl S, Ferracane JL. Influence of photoinitiator type on the rate of polymerization, degree of conversion, hardness and yellowing of dental resin composites. Dent Mater. 2008. 24:1169–1177.
18. Nomoto R. Effect of light wavelength on polymerization of light-cured resins. Dent Mater J. 1997. 16:60–73.
19. Arikawa H, Fujii K, Kanie T, Inoue K. Light transmittance characteristics of light-cured composite resins. Dent Mater. 1998. 14:405–411.
20. Oysaed H, Ruyter IE. Water sorption and filler characteristic of composites for use in posterior teeth. J Dent Res. 1986. 65:1315–1318.
21. Inokoshi S, Burrow MF, Kataumi M, Yamada T, Takatsu T. Opacity and color changes of tooth-colored restorative materials. Oper Dent. 1996. 21:73–80.
Full Text Links
export Copy
  • Twitter
  • Facebook
Similar articles
Copyright © 2023 by Korean Association of Medical Journal Editors. All rights reserved.     E-mail: koreamed@kamje.or.kr