The Journal of Contemporary Dental Practice

Register      Login



Volume / Issue

Online First

Related articles

VOLUME 22 , ISSUE 2 ( February, 2021 ) > List of Articles


Effect of LEDs with Different Wavelengths on the Microhardness and Nanohardness of Nanohybrid Composite Resins

Jesuína L N Araújo, Cristiane de Melo Alencar, Gabriela M Barbosa, Cecy M Silva, Míriam L Turbino

Keywords : Composite resin, Microhardness, Nanohardness, Photocuring

Citation Information : Araújo JL, Alencar CD, Barbosa GM, Silva CM, Turbino ML. Effect of LEDs with Different Wavelengths on the Microhardness and Nanohardness of Nanohybrid Composite Resins. J Contemp Dent Pract 2021; 22 (2):122-127.

DOI: 10.5005/jp-journals-10024-3032

License: CC BY-NC 4.0

Published Online: 17-12-2021

Copyright Statement:  Copyright © 2021; Jaypee Brothers Medical Publishers (P) Ltd.


Aim: The aim of this study is to compare the effectiveness of polymerization of nanohybrid composite resins with different colors and thicknesses, photocured by units of different wavelengths through Knoop microhardness (KHN) and Berkovich nanohardness (DUH). Materials and methods: One hundred twenty specimens of Tetric N-Ceram (Ivoclar/Vivadent) were divided into groups (n = 5) according to the experimental test, the color of the composite resin (A2 and Bleach-M/BM), the light source: monowave (Elipar™ FreeLight DeepCure-3M/ESPE), dental products—1200 mW/cm²/15 seconds (FL); or polywave (Bluephase-Ivoclar/Vivadent 1200 mW/cm²/15 and 30 seconds (BP), and thickness (irradiated surface,1, 2, and 3 mm). The specimens were stored dry for 24 hours at 37°C and received five indentations on the top and button surfaces. Analysis of variance (ANOVA), Tukey, and Pearson correlation (p < 0.01%) tests were used. Results: A direct correlation was found between KHN and DUH. The higher values of KHN and DUH were observed with Elipar™ FreeLight DeepCure unit in irradiated surface and 1-mm-thick specimens at A2 color. Conclusion: That Elipar™ FreeLight DeepCure unit showed better effectiveness in curing nanohybrid composite resins, used in this work, in different colors and depths as compared to Bluephase in both experimental tests, and that DUH can substitute KHN test when comparing the effectiveness of polymerization. Clinical significance: The evaluation of the mechanical properties of composite resins is essential to verify their possible clinical performance.

  1. Fugolin APP, Pfeifer CS. New resins for dental composites. J Dent Res 2017;96(10):1085–1091. DOI: 10.1177/0022034517720658.
  2. Alzraikat H, Burrow MF, Maghaireh GA, et al. Nanofilled resin composite properties and clinical performance: a review. Oper Dent 2018;43(4):E173–E190. DOI: 10.2341/17-208-T.
  3. Roy KK, Kumar KP, John G, et al. A comparative evaluation of effect of modern-curing lights and curing modes on conventional and novel-resin monomers. J Conserv Dent 2018;21(1):68. DOI: 10.4103/JCD.JCD_71_17.
  4. Frauscher KE, Ilie N. Depth of cure and mechanical properties of nano-hybrid resin-based composites with novel and conventional matrix formulation. Clin Oral Investing 2012;16(5):1425–1434. DOI: 10.1007/s00784-011-0647-3.
  5. Colombo M, Gallo S, Poggio C, et al. New resin-based bulk-fill composites: in vitro evaluation of micro-hardness and depth of cure as infection risk indexes. Materials 2020;13(6):1308. DOI: 10.3390/ma13061308.
  6. Labban N, Iskandar M, Platt JA, et al. The influence of delayed light curing on the degree of conversion and polymerization contraction stress in dual-cured resin luting agents. J Adhesion Sci Technol 2018;32(5):516–526. DOI: 10.1080/01694243.2017.1370165.
  7. Al-Zain AO, Marghalani HY. Influence of light-curing distances on microflexural strength of two resin-based composites. Oper Dent 2020;45(3):297–305. DOI: 10.2341/19-001-L.
  8. Price RB. The dental curing light. In: Dental Composite Materials for Direct Restorations. Cham: Springer; 2018, pp. 43–62. DOI: 10.1007/978-3-319-60961-4_4.
  9. André CB, Nima G, Sebold M, et al. Stability of the light output, oral cavity tip accessibility in posterior region and emission spectrum of light-curing units. Oper Dent 2018;43(4):398–407. DOI: 10.2341/17-033-L.
  10. Gan JK, Yap AU, Cheong JW, et al. Bulk-fill composites: effectiveness of cure with poly-and monowave curing lights and modes. Oper Dent 2018;43(2):136–143. DOI: 10.2341/16-304-L.
  11. Price RBT. Light curing in dentistry. Dent Clin 2017;61(4):751–778. DOI: 10.1016/j.cden.2017.06.008.
  12. Conte G, Panetta M, Mancini M, et al. Curing effectiveness of single-peak and multi-peak led light curing units on tpo-containing resin composites with different chromatic characteristics. Oral Implantol 2017;10(2):140. DOI: 10.11138/orl/2017.10.2.140.
  13. Price RBT, Felix CA. Effect of delivering light in specific narrow bandwidths from 394 to 515 nm on the micro-hardness of resin composites. Dent Mater 2009;25(7):899–908. DOI: 10.1016/
  14. Santini A, Miletic V, Swift MD, et al. Degree of conversion and microhardness of TPO-containing resin-based composites cured by polywave and monowave LED units. J Dent 2012;40(7):577–584. DOI: 10.1016/j.jdent.2012.03.007.
  15. Delgado AJ, Castellanos EM, Sinhoreti M, et al. The use of different photoinitiator systems in photopolymerizing resin cements through ceramic veneers. Oper Dent 2019;44(4):396–404. DOI: 10.2341/17-263-L.
  16. Okawa T, Clark IT, Tashiro K, et al. Area function for nanoindentation at high temperatures. Int J Mate Sci Appl 2019;8(6):98. DOI: 10.11648/j.ijmsa.20190806.11.
  17. Alsayed EZ, Hariri I, Nakashima S, et al. Effects of coating materials on nanoindentation hardness of enamel and adjacent areas. Dent Mater 2016;32(6):807–816. DOI: 10.1016/
  18. Choudhary S, Suprabha BS. Effectiveness of light emitting diode and halogen light curing units for curing microhybrid and nanocomposites. J Conserv Dent 2013;16(3):233. DOI: 10.4103/0972-0707.111322.
  19. Lucca DA, Herrmann K, Klopfstein MJ. Nanoindentation: measuring methods and application. CIRP Ann 2010;59(2):803–819. DOI: 10.1016/ j.cirp.2010.05.009.
  20. Santini A. Current status of visible light activation units and the curing of light-activated resin-based composite materials. Dent Update 2010;37(4):214–227. DOI: 10.12968/denu.2010.37.4.214.
  21. Ikemura K, Ichizawa K, Yoshida M, et al. UV–vis spectra and photoinitiation behaviors of acylphosphine oxide and bisacylphosphine oxide derivatives in unfilled, light-cured dental resins. Dent Mater J 2008;27:765–774. DOI: 10.4012/dmj.27.765.
  22. Albuquerque PPA, Bertolo ML, Cavalcante LM, et al. Degree of conversion, depth of cure, and color stability of experimental dental composite formulated with camphorquinone and phenanthrenequinone photoinitiators. J Esthet Restor Dent 2015;27:S49–S57. DOI: 10.1111/jerd.12131.
  23. Derchi G, Vano M, Ceseracciu L, et al. Stiffness effect of using polywave or monowave LED units for photo-curing different bulk fill composites. Dent Mater J 2018;2017:278. DOI: 10.4012/dmj.2017-278.
  24. Bortolotto T, Betancourt F, Krejci I. Marginal integrity of resin composite restorations restored with PPD initiatorcontaining resin composite cured by QTH, monowave and polywave LED units. Dent Mater J 2016;2015:339. DOI: 10.4012/dmj.2015-339.
  25. Miletic V, Santini A. Micro-Raman spectroscopic analysis of the degree of conversion of composite resins containing different initiators cured by polywave or monowave LED units. J Dent 2012;40(2):106–113. DOI: 10.1016/j.jdent.2011.10.018.
  26. Rueggeberg FA, Giannini M, Arrais CAG, et al. Light curing in dentistry and clinical implications: a literature review. Braz Oral Res 2017;31:e61. DOI: 10.1590/1807-3107bor.
  27. Ferracane JL, Greener EH. Fourier transform infrared analysis of degree of polymerization in unfilled resins–methods comparison. J Dent Res 1984;63(8):1093–1095. DOI: 10.1177/00220345840630081901.
  28. Ilie N, Rencz A, Hickel R. Investigations towards nano-hybrid resin-based composites. Clin Oral Investig 2013;17(1):185–193. DOI: 10.1007/s00784-012-0689-1.
  29. Andrade KC, Pini NIP, Moda MD, et al. Influence of different light-curing units in surface roughness and gloss of resin composites for bleached teeth after challenges. J Mech Behav Biomed Mater 2020;102:103458. DOI: 10.1016/j.jmbbm.2019.103458.
  30. Jeong TS, Kang HS, Kim SK, et al. The effect of resin shades on microhardness, polymerization shrinkage, and color change of dental composite resins. Dent Mater J 2009;28(4):38–45. DOI: 10.4012/dmj.28.438.
  31. Leprince JG, Hadis M, Shortall AC, et al. Photoinitiator type and applicability of exposure reciprocity law in filled and unfilled photoactive resins. Dent Mater 2011;27(2):157–164. DOI: 10.1016/
  32. Schuh CA. Nanoindentation studies of materials. J Mater Res 2006;9(5):32–40. DOI: 10.1016/S1369-7021(06)71495-X.
  33. Willems G, Celis JP, Lambrechts P, et al. Hardness and Young's modulus determined by nanoindentation technique of filler particles of dental restorative materials compared with human enamel. J Biomed Mater Res 1993;27:747–755. DOI: 10.1002/jbm.820270607.
  34. Lewis G, Nyman JS. The use of nanoindentation for characterizing the properties of mineralized hard tissues: state-of-the art review. J Biomed Mater Res Part B Appl Biomater 2008;87(1):286–301. DOI: 10.1002/jbm.b.31092.
PDF Share
PDF Share

© Jaypee Brothers Medical Publishers (P) LTD.