Abstract
Many dental bleaching techniques are now available, several of them using a laser source. However, the literature on the exact role of coherent light in the biochemical reaction of the whitening process is very discordant. The aims of this in vitro study were: (1) to compare two different laser sources, a KTP laser with a wavelength of 532 nm and a diode laser with a wavelength of 808 nm, during dental bleaching, and (2) to investigate the relationships among changes in gel temperature, tooth shade and hydrogen peroxide (HP) concentration during laser irradiation. Altogether, 116 bovine teeth were bleached using a 30% HP gel, some of them with gel only and others with gel plus one of the two lasers (532 or 808 nm) at two different powers (2 and 4 W). The KTP laser produced a significant shade variation with a minimal temperature increase. The diode laser led to a higher temperature increase with a greater reduction in HP concentration, but the change in shade was only statistically significant with a power of 4 W. At a power of 2 W, the KTP laser caused a greater change in shade than the diode laser. No significant correlations were found among temperature, HP concentration and shade variation. The KTP laser appears to provide better results with less dangerous thermal increases than the diode laser. This might call into question most of the literature affirming that the action of laser bleaching is by increasing the gel temperature and, consequently, the speed of the redox reaction. Further study is required to investigate the correlations between the parameters investigated and efficacy of the bleaching process.
Similar content being viewed by others
References
Dahl JE, Pallesen U (2003) Tooth bleaching – a critical review of the biological aspects. Crit Rev Oral Biol Med 14:292–304
Garber DA, Goldstein RE, Goldstein GE, Schwartz CG (1991) Dentist monitored bleaching: a combined approach. Pract Periodontics Aesthet Dent 3:22–26
Sulieman M (2008) An overview of tooth-bleaching techniques: chemistry, safety and efficacy. Periodontol 2000 48:148–169
Luna AJ, Nascimento CAO, Chiavone-Filho O (2006) Photodecomposition of hydrogen peroxide in highly saline aqueous medium. Braz J Chem Eng 23:341–349
Nathoo SA, Gaffar A (1995) Studies on dental stains induced by antibacterial agents and rational approaches for bleaching dental stains. Adv Dent Res 9:462–470
Luk K, Tam L, Hubert M (2004) Effect of light energy on peroxide tooth bleaching. J Am Dent Assoc 135:194–201
Strobl A, Gutknecht N, Franzen R, Hilgers RD, Lampert F, Meister J (2010) Laser-assisted in-office bleaching using a neodymium:yttrium-aluminum-garnet laser: an in vivo study. Lasers Med Sci 25:503–509
Kinoshita JI, Jafarzadeh H, Forghani M (2009) Vital bleaching of tetracycline stained teeth by using KTP laser: case report. Eur J Dent 3:229–232
Dostalova T, Jelinkova H, Housova D, Sulc J, Nemec M, Miyagi M, Brugnera Junior A, Zanin F (2004) Diode laser-activated bleaching. Braz Dent J 15 (Spec no):SI3–SI8
Polydorou O, Hellwig E, Hahn P (2008) The efficacy of three different in-office bleaching systems and their effect on enamel microhardness. Oper Dent 33:579–586
Wutter NU, Barroso MC, Pelino JE (2004) Dental bleaching efficacy with diode laser and LED irradiation: an in vitro study. Lasers Surg Med 35:254–258
Joiner A (2006) The bleaching of teeth: a review of the literature. J Dent 34:412–419
Chu SJ (2002) The science of color and shade selection in aesthetic dentistry. Dent Today 21:86–89
Sfreddo M, Mason E (2005) Valutazione dello sbiancamento dentale mediante spettrofotometria e SEM. Quintessenza Int 5:55–76
Glodberg M, Grootveld M, Lynch E (2010) Undesirable and adverse effect of tooth-whitening products: a review. Clin Oral Invest 14:1–10
Kwon YH, Huo MS, Kim KH (2002) Effect of hydrogen peroxide on the light reflectance and morphology of bovine enamel. J Oral Rehabil 29:473–477
Nascimento EA, Machado AEH, Morais S (1995) Photochemical hydrogen peroxide bleaching of eucalyptus organosolv pulp. J Braz Chem Soc 6:365–371
Carrasco TG, Carrasco-Guerisoli LD, Fröner IC (2008) In vitro study of the pulp chamber temperature rise during light-activated bleaching. J Appl Oral Sci 16:355–359
Marcondes M, Paranhos MP, Spohr AM, Mota EG, da Silva IN, Souto AA, Burnett LH Jr (2009) The influence of the Nd:YAG laser bleaching on Physical and Mechanical Properties of the Dental Enamel. J Biomed Mater Res Part B 90 B:388–395
Goharkhay K, Schoop U, Wernisch J, Hartl S, De Moor R, Moritz A (2009) Frequency doubled neodymium:yttrium-aluminum-garnet and diode laser-activated power bleaching--pH, environmental scanning electron microscopy, and colorimetric in vitro evaluations. Lasers Med Sci 24:339–346
Fornaini C, Rocca JP, Merigo E, Meleti M, Manfredi M, Nammour S, Vescovi P (2011)Low energy KTP laser in oral soft tissue surgery: a 52 patients clinical study. Med Oral Patol Oral Cir Bucal. doi:10.4317/medoral.17428
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
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 28, 1–6 (2013). https://doi.org/10.1007/s10103-011-1037-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10103-011-1037-4