The Journal of Contemporary Dental Practice

Register      Login



Volume / Issue

Online First

Related articles

VOLUME 19 , ISSUE 2 ( February, 2018 ) > List of Articles


Influences of Light-emitting Diode Illumination Bleaching Technique on Nanohardness of Computer-aided Design and Computer-aided Manufacturing Ceramic Restorative Materials

Apa Juntavee, Niwut Juntavee, Phuwiwat Saensutthawijit

Citation Information : Juntavee A, Juntavee N, Saensutthawijit P. Influences of Light-emitting Diode Illumination Bleaching Technique on Nanohardness of Computer-aided Design and Computer-aided Manufacturing Ceramic Restorative Materials. J Contemp Dent Pract 2018; 19 (2):196-204.

DOI: 10.5005/jp-journals-10024-2236

License: CC BY 3.0

Published Online: 01-04-2013

Copyright Statement:  Copyright © 2018; The Author(s).



This study evaluated the effect of light-emitting diode (LED) illumination bleaching technique on the surface nanohardness of various computer-aided design and computer-aided manufacturing (CAD/CAM) ceramic materials.

Materials and methods

Twenty disk-shaped samples (width, length, and thickness = 10, 15, and 2 mm) were prepared from each of the ceramic materials for CAD/CAM, including Lava™ Ultimate (LV), Vita Enamic® (En) IPS e.max® CAD (Me), inCoris® TZI (IC), and Prettau® zirconia (Pr). The samples from each type of ceramic were randomly divided into two groups based on the different bleaching techniques to be used on them, using 35% hydrogen peroxide with and without LED illumination. The ceramic disk samples were bleached according to the manufacturer's instruction. Surface hardness test was performed before and after bleaching using nanohardness tester with a Berkovich diamond indenter.


The respective Vickers hardness number upon no bleaching and bleaching without or with LED illumination [mean ± standard deviation (SD)] for each type of ceramic were as follows: 102.52 ± 2.09, 101.04 ± 1.18, and 98.17 ± 1.15 for LV groups; 274.96 ± 5.41, 271.29 ± 5.94, and 268.20 ± 7.02 for En groups; 640.74 ± 31.02, 631.70 ± 22.38, and 582.32 ± 33.88 for Me groups; 1,442.09 ± 35.07, 1,431.32 ± 28.80, and 1,336.51 ± 34.03 for IC groups; and 1,383.82 ± 33.87, 1,343.51 ± 38.75, and 1,295.96 ± 31.29 for Pr groups. The results indicated surface hardness reduction following the bleaching procedure of varying degrees for different ceramic materials. Analysis of variance (ANOVA) revealed a significant reduction in surface hardness due to the effect of bleaching technique, ceramic material, and the interaction between bleaching technique and ceramic material (p < 0.05).


Bleaching resulted in a diminution of the surface hardness of dental ceramic for CAD/CAM. Using 35% hydrogen peroxide bleaching agent with LED illumination exhibited more reduction in surface hardness of dental ceramic than what was observed without LED illumination.

Clinical significance

Clinicians should consider protection of the existing restoration while bleaching.

How to cite this article

Juntavee N, Juntavee A, Saensutthawijit P. Influences of Light-emitting Diode Illumination Bleaching Technique on Nanohardness of Computer-aided Design and Computer-aided Manufacturing Ceramic Restorative Materials. J Contemp Dent Pract 2018;19(2):196-204.

  1. Eight in-office tooth whitening systems evaluated in vivo: a pilot study. Oper Dent 2007 Jul-Aug;32(4):322-327.
  2. Night guard vital bleaching. Quintessence Int 1989 Mar;20(3):173-176.
  3. Tooth bleaching—a critical review of the biological aspects. Crit Rev Oral Biol Med 2003;14(4):292-304.
  4. Nonvital tooth bleaching: a review of the literature and clinical procedures. J Endod 2008 Apr;34(4):394-407.
  5. Clinical evaluation of in-office dental bleaching treatments with and without the use of light-activation sources. Oper Dent 2008 Jan-Feb;33(1):15-22.
  6. Effects of KTP laser irradiation, diode laser, and LED on tooth bleaching: a comparative study. Photomed Laser Surg 2007 Apr;25(2):91-95.
  7. Safety issues when using carbamide peroxide to bleach vital teeth—a review of the literature. Eur J Prosthodont Restor Dent 2003 Mar;11(1):9-13.
  8. Cytotoxicity and dentin permeability of carbamide peroxide and hydrogen peroxide vital bleaching materials, in vitro. J Dent Res 1993 May;72(5):931-938.
  9. Review of the current status of tooth whitening with the walking bleach technique. Int Endod J 2003 May;36(5):313-329.
  10. Incidence of external root resorption and esthetic results in 58 bleached pulpless teeth. Endod Dent Traumatol 1988 Feb;4(1):23-26.
  11. A review of dental CAD/CAM: current status and future perspectives from 20 years of experience. Dent Mater J 2009 Jan;28(1):44-56.
  12. Emerging ceramic-based materials for dentistry. J Dent Res 2014 Dec;93(12):1235-1242.
  13. Effects of in-office tooth whiteners on hardness of tooth-colored restoratives. Oper Dent 2002 Mar-Apr;27(2):137-141.
  14. Effect of bleaching on restorative materials and restorations-a systematic review. Dent Mater 2004 Nov;20(9):852-861.
  15. The effect of a bleaching system on properties related to different ceramic surface textures. J Prosthodont 2009 Apr;18(3):223-229.
  16. Effect of different concentrations of carbamide peroxide on microhardness of dental ceramics. Am J Dent 2011 Feb;24(1):57-59.
  17. Discoloration of restorative materials after bleaching application. Quintessence Int 2005 Jan;36(1):33-39.
  18. Changes in the mechanical properties and surface texture of compomer immersed in various media. J Prosthet Dent 2000 Oct;84(4):444-452.
  19. Effects of home bleaching products on composite resins. Quintessence Int 1992 Jul;23(7):489-494.
  20. Degradability of dental ceramics. Adv Dent Res 1992 Sep;6(1):82-89.
  21. Flexural strength and fracture toughness of dental core ceramics. J Prosthet Dent 2007 Aug;98(2):120-128.
  22. The effect of bleaching agents on the microhardness of dental aesthetic restorative materials. J Oral Rehabil 2002 Jul;29(7):657-661.
  23. The relationship between composition and properties of posterior resin composites. J Dent Res 1990 Mar;69(3):852-856.
  24. Effects of bleaching gels on the surface microhardness of tooth-colored restorative materials in situ. J Dent 2008 Apr;36(4):261-267.
  25. The effect of at-home bleaching on the microhardness of six esthetic restorative materials. J Am Dent Assoc 2007 Jul;138(7):978-984.
  26. The effect of home bleaching agents on the surface roughness of tooth-colored restoratives with time. Oper Dent 2004 Jul-Aug;29(4):398-403.
  27. Carbamide peroxide bleaching agents: effects on surface roughness of enamel, composite and porcelain. Clin Oral Investig 2006 Mar;10(1):23-28.
  28. Indentation properties of young and old osteons. Calcif Tissue Int 2006 Jun;78(6):392-397.
PDF Share
PDF Share

© Jaypee Brothers Medical Publishers (P) LTD.