• Logo
  • SBMUJournals

Comparison of Tooth Color Change After Bleaching With Conventional and Different Light-Activated Methods

Sima Shahabi, Hadi Assadian, Alireza Mahmoudi Nahavandi, Hanieh Nokhbatolfoghahaei



Introduction: The demand for esthetic dental treatments is increasing in recent years mainly due to improved oral hygiene and better maintenance of oral health and teeth in older individuals. Bleaching of discolored anterior teeth is the most popular among esthetic dental treatments. Even individuals with sound teeth and adequate esthetics seek to have whiter teeth in the anterior region. The aim of this study was to evaluate tooth color changes following conventional in-office bleaching techniques compared to light-activated methods using different light sources.
Methods: Seventy sound anterior teeth (devoided of caries and/or fracture), extracted for periodontal and orthodontic reasons were selected and allocated to 7 groups: (A) control, (B) conventional bleaching (C) LED-activated bleaching, (D) KTP laser-activated bleaching, (E) diode laser-activated bleaching, (F) Nd:YAG laser-activated bleaching and (G) CO2 laser-activated bleaching. Colorimetric evaluation was carried out before and after treatment using a spectrophotoradiometer. Data were analyzed by one- and two-way analysis of variance (ANOVA) as well as multiple comparison methods.
Results: The results showed that all bleaching procedures were effective in reducing the yellowness index. However, the KTP laser-activated bleaching was significantly more effective than the other techniques in 95% confidence level. It was also seen that CO2 laser activated method has outperformed groups E, F and G and the conventional bleaching without light activation was not effective at all and represented similar results with the control group. Furthermore, the groups E and G had almost the same results in decreasing the yellowness index.
Conclusion: The results showed that all bleaching techniques were effective however, the KTP laser-activated bleaching was significantly more efficient, closely followed by the CO2 laser-activated bleaching technique.


Laser bleaching; Tooth color change; Spectroradiometer.


Fornaini C, Lagori G, Merigo E, et al. Analysis of shade, temperature and hydrogen peroxide concentration during dental bleaching: in vitro study with the KTP and diode lasers. Lasers Med Sci. 2013;28(1):1-6. doi:10.1007/s10103- 011-1037-4

Burrows S. A review of the efficacy of tooth bleaching. Dent Update. 2009;36(9):537-538, 541-534, 547-538 passim.

Matis BA, Cochran MA, Eckert G. Review of the effectiveness of various tooth whitening systems. Oper Dent. 2009;34(2):230-235. doi:10.2341/08-74

Mondelli RF, Azevedo JF, Francisconi AC, Almeida CM, Ishikiriama SK. Comparative clinical study of the effectiveness of different dental bleaching methods - two year follow-up. J Appl Oral Sci. 2012;20(4):435-443.

Joiner A. The bleaching of teeth: a review of the literature. J Dent. 2006;34(7):412-419. doi:10.1016/j.jdent.2006.02.002

Dostalova T, Jelinkova H, Housova D, et al. Diode laser-activated bleaching. Braz Dent J. 2004;15 Spec No:Si3-8.

Sulieman MA. An overview of tooth-bleaching techniques: chemistry, safety and efficacy. Periodontol 2000. 2008;48:148-169. doi:10.1111/j.1600-0757.2008.00258.x

Summitt JB, Robbins JW, Hilton TJ, Schwartz RS, Dos Santos JR Jr. Fundamentals of operative dentistry: a contemporary approach. 3rd ed. Quintessence: Chicago; 2006.

Joiner A. Review of the effects of peroxide on enamel and dentine properties. J Dent. 2007;35(12):889-896. doi:10.1016/j.jdent.2007.09.008

Buchalla W, Attin T. External bleaching therapy with activation by heat, light or laser--a systematic review. Dent Mater. 2007;23(5):586-596. doi:10.1016/j. dental.2006.03.018

Bernardon JK, Sartori N, Ballarin A, Perdigao J, Lopes GC, Baratieri LN. Clinical performance of vital bleaching techniques. Oper Dent. 2010;35(1):3-10. doi:10.2341/09- 008cr

Marson FC, Sensi LG, Vieira LC, Araujo E. Clinical evaluation of in-office dental bleaching treatments with and without the use of light-activation sources. Oper Dent. 2008;33(1):15-22. doi:10.2341/07-57

Ontiveros JC, Paravina RD. Color change of vital teeth exposed to bleaching performed with and without supplementary light. J Dent. 2009;37(11):840-847. doi:10.1016/j.jdent.2009.06.015

Sulieman M, Addy M, Macdonald E, Rees JS. A safety study in vitro for the effects of an in-office bleaching system on the integrity of enamel and dentine. J Dent. 2004;32(7):581- 590.

Kiomars N, Azarpour P, Mirzaei M, Hashemi Kamangar SS, Kharazifard MJ, Chiniforush N. Evaluation of the Diode laser (810nm, 980 nm) on color change of teeth after external bleaching. Laser Ther. 2016;25(4):267-272. doi:10.5978/islsm.16-OR-21

Linkevicius T, Vindasiute E, Puisys A, Linkeviciene L, Maslova N, Puriene A. The influence of the cementation margin position on the amount of undetected cement. A prospective clinical study. Clin Oral Implants Res. 2013;24(1):71-76. doi:10.1111/j.1600-0501.2012.02453.x

Dozic A, Kleverlaan CJ, El-Zohairy A, Feilzer AJ, Khashayar G. Performance of five commercially available tooth color-measuring devices. J Prosthodont. 2007;16(2):93-100. doi:10.1111/j.1532-849X.2007.00163.x

Johnston WM. Color measurement in dentistry. J Dent. 2009;37 Suppl 1:e2-6. doi:10.1016/j.jdent.2009.03.011

Wadhwani C, Hess T, Faber T, Pineyro A, Chen CS. A descriptive study of the radiographic density of implant restorative cements. J Prosthet Dent. 2010;103(5):295-302. doi:10.1016/s0022-3913(10)60062-5

Braun A, Jepsen S, Krause F. Spectrophotometric and visual evaluation of vital tooth bleaching employing different carbamide peroxide concentrations. Dent Mater. 2007;23(2):165-169. doi:10.1016/j.dental.2006.01.017

Joiner A. Tooth colour: a review of the literature. J Dent. 2004;32 Suppl 1:3-12.

Bolt RA, Bosch JJ, Coops JC. Influence of window size in small-window colour measurement, particularly of teeth. Phys Med Biol. 1994;39(7):1133-1142.

Wetter NU, Barroso MC, Pelino JE. Dental bleaching efficacy with diode laser and LED irradiation: an in vitro study. Lasers Surg Med. 2004;35(4):254-258. doi:10.1002/ lsm.20103

Luk K, Tam L, Hubert M. Effect of light energy on peroxide tooth bleaching. J Am Dent Assoc. 2004;135(2):194-201; quiz 228-199.

Kuzekanani M, Walsh LJ. Quantitative analysis of KTP laser photodynamic bleaching of tetracycline-discolored teeth. Photomed Laser Surg. 2009;27(3):521-525. doi:10.1089/ pho.2008.2332

Zhang C, Wang X, Kinoshita J, et al. Effects of KTP laser irradiation, diode laser, and LED on tooth bleaching: a comparative study. Photomed Laser Surg. 2007;25(2):91-95. doi:10.1089/pho.2006.2025

Strobl A, Gutknecht N, Franzen R, Hilgers RD, Lampert F, Meister J. Laser-assisted in-office bleaching using a neodymium:yttrium-aluminum-garnet laser: an in vivo study. Lasers Med Sci. 2010;25(4):503-509. doi:10.1007/ s10103-009-0675-2

Marcondes M, Paranhos MP, Spohr AM, et al. The influence of the Nd:YAG laser bleaching on physical and mechanical properties of the dental enamel. J Biomed Mater Res B Appl Biomater. 2009;90(1):388-395. doi:10.1002/jbm.b.31297