Lasers in Medical Science

, Volume 26, Issue 1, pp 35–42 | Cite as

Evaluation of carbon dioxide laser irradiation associated with calcium hydroxide in the treatment of dentinal hypersensitivity. A preliminary study

  • Ana Cristina Cury Camargo Romano
  • Ana Cecilia Corrêa Aranha
  • Bruno Lopes da Silveira
  • Sônia Lícia Baldochi
  • Carlos de Paula Eduardo
Original Article


Attempts have been made to treat dentinal hypersensitivity by sealing exposed dentinal tubules, and the carbon dioxide (CO2) laser has been shown to have a sealing effect on dentinal surfaces. The purpose of this study was to analyze the morphological ultra-structure and temperature change after CO2 laser irradiation of dentin. Fourteen human third molars were selected and cleaned. An area was delimited, and the samples were randomly divided into seven groups: Group 1 (G1): control; G2, calcium hydroxide paste (CA) + CO2 laser (L) (0.5 W/63,69 W/cm2); G3, CA + L (1 W/125,38 W/cm2); G4, CA + L (1.5 W/191,08 W/cm2); G5, L (0.5 W); G6, L (1 W); G7, L (1.5 W). All irradiation was performed in unfocused mode. The electron micrographs were analyzed by three observers. For temperature analysis, a thermocouple was used. Data were subjected to statistical analysis. The Kruskal–Wallis non-parametric test showed statistical differences between the groups (P < 0.05). For the two by two comparisons, all groups treated with calcium hydroxide paste presented significantly higher mean scores. In the groups treated by CO2 laser only, fusion, re-crystallization, cracks and carbonization were observed. A change of 1 ± 5°C was noted in the temperature. Under the limitation of an in vitro study, and with the protocols used, we concluded that CO2 laser is safe to use for the establishment of partial fusion and re-solidification of the dentinal surface.


CO2 laser Calcium hydroxide Dentin hypersensitivity 



The authors wish to express their gratitude to the Special Laboratory of Lasers in Dentistry (LELO) at the University of São Paulo, Brazil. They thank the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) for financial support, the Mestrado Profissionalizante de Lasers em Odontologia (MPLO; Professional Master’s Course in Lasers in Dentistry) and Fundação para o Desenvolvimento Científico e Tecnológico da Odontologia (FUNDECTO; Foundation for the Scientific and Technological Development of Dentistry) for the use of the CO2 laser.


  1. 1.
    Yoshiyama M, Niori Y, Ozaki K, Uchida A, Ishikawa Y (1990) Transmission electron microscopic characterization of hypersensitive human dentin. J Dent Res 69:1293–1297PubMedGoogle Scholar
  2. 2.
    Yoshiyama M, Suge T, Kawasaki A, Ebisu S (1996) Morphological characterization of tubule-like structure in hypersensitive human radicular dentin. J Dent 24:57–63CrossRefPubMedGoogle Scholar
  3. 3.
    Orchardson R, Gillam DG (2006) Managing dentin hypersensitivity. J Am Dent Assoc 137:990–998PubMedGoogle Scholar
  4. 4.
    Pashley DH (1986) Sensitivity of dentin to chemical stimuli. Endodont Dent Traumatol 2:130–137CrossRefGoogle Scholar
  5. 5.
    Jacobsen PL, Bruce G (2001) Clinical dentin hypersensitivity: understanding the causes and prescribing a treatment. J Contemp Dent Pract 2:1–8PubMedGoogle Scholar
  6. 6.
    Bartold PM (2006) Dentinal hypersensitivity: a review. Aust Dent J 51:212–218CrossRefPubMedGoogle Scholar
  7. 7.
    Tanji EY, Matsumoto K (1994) The comparative study of the morphological changes of dentin surface after Nd:YAG, CO2 and argon lasers irradiation. J Jpn Endod Assoc 15:14–20Google Scholar
  8. 8.
    Yonaga K, Kimura Y, Matsumoto K (1999) Treatment of cervical dentin hypersensitivity by various methods using pulsed Nd: YAG laser. J Clin Laser Med Surg 17:205–210PubMedGoogle Scholar
  9. 9.
    Wakabayashi H, Hamba M, Matsumoto K, Tachibana H (1993) Effect of irradiation by semiconductor laser on responses evoked in trigeminal caudal neurons by tooth pulp stimulation. Lasers Surg Med 13:605–619CrossRefPubMedGoogle Scholar
  10. 10.
    Birang R, Poursamimi J, Gutknecht N, Lampert F, Mir M (2007) Comparative evaluation of the effects of Nd:YAG and Er:YAG laser in dentin hypersensitivity treatment. Lasers Med Sci 22:21–24CrossRefPubMedGoogle Scholar
  11. 11.
    Ling TYY, Gillam DG (1996) The effectiveness of desensitizing agents for the treatment of cervical dentin sensitivity. A review. J West Soc Periodontol Periodontal Abstr 44:5–12PubMedGoogle Scholar
  12. 12.
    Zhang C, Matsumoto K, Kimura Y, Harashima T, Takeda F, Zhou H (1998) Effects of CO2 laser in treatment of cervical dentin hypersensitivity. J Endod 24:595–597CrossRefPubMedGoogle Scholar
  13. 13.
    Olsson H, Petersson K, Rohlin M (2006) Formation of a hard tissue barrier after pulp cappings in humans. A systematic review. Int Endod J 39:429–442CrossRefPubMedGoogle Scholar
  14. 14.
    Moritz A, Gutknecht N, Schoop U, Goharkhay K, Ebrahim D, Wernisch J, Sperr W (1996) The advantage of CO2-treated dental necks, in comparison with a standard method: results of an in vivo study. J Clin Laser Med Surg 14:27–32PubMedGoogle Scholar
  15. 15.
    Moritz A, Schoop U, Goharkhay K, Aoid M, Reichenbach P, Lothaller MA, Wernisch J, Sperr W (1998) Long-term effects of CO2 laser irradiation on treatment of hypersensitive dental necks: results of an in vivo study. J Clin Laser Med Surg 16:211–215PubMedGoogle Scholar
  16. 16.
    Misra V, Mehrotra J, Dixit J, Maitra SC (1999) Effects of a carbon dioxide laser on periodontally involved root surface. J Periodontol 70:1046–1052CrossRefPubMedGoogle Scholar
  17. 17.
    Steiner-Oliveira C, Rodrigues LK, Soares LE, Martin AA, Zezell DM, Nobre-dos-Santos M (2006) Chemical, morphological and thermal effects of 10.6-microm CO2 laser on the inhibition of enamel demineralization. Dent Mater J 25:455–462CrossRefPubMedGoogle Scholar
  18. 18.
    Sasaki KM, Aoki A, Masuno H, Ichinose S, Yamada S, Ishikawa I (2002) Compositional analysis of root cementum and dentin after Er:YAG laser irradiation compared with CO2 laser and intact roots using Fourier transformed infrared spectroscopy. J Periodont Res 5:50–59CrossRefGoogle Scholar
  19. 19.
    Zach I, Cohen G (1965) Pulp response to externally applied heat. Oral Surg Oral Med Oral Pathol 19:515–530CrossRefPubMedGoogle Scholar
  20. 20.
    Grossman LI (1935) A systematic method for the treatment of hypersensitive dentin. J Am Dent Assoc 22:592–602Google Scholar
  21. 21.
    Pashley E, Horner H, Liu M, Kim S, Pashley D (1992) The effects of CO2 laser energy on dentin permeability. J Dent Res 71:162Google Scholar
  22. 22.
    Luomanen M, Hemmerlé J, Voege CJ, Rauhamaa R, Meurman JH (1998) Transformation of hydroxyapatite to fluorapatite with CO2 laser irradiation. Proceedings of the 6th International Congress on Lasers in Dentistry. International Society for Lasers In Dentistry, Maui, Hawaii, pp 72–73Google Scholar
  23. 23.
    Lan WH, Chen KW, Jeng JH, Lin CP, Lin SK (2000) A comparison of the morphological changes after Nd:YAG and CO2 laser irradiation of dentin surfaces. J Endod 26:450CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag London Ltd 2010

Authors and Affiliations

  • Ana Cristina Cury Camargo Romano
    • 1
  • Ana Cecilia Corrêa Aranha
    • 2
  • Bruno Lopes da Silveira
    • 3
  • Sônia Lícia Baldochi
    • 4
  • Carlos de Paula Eduardo
    • 2
  1. 1.Lasers in Dentistry, School of DentistryUniversity of São Paulo (USP)São PauloBrazil
  2. 2.Department of Restorative Dentistry, Special Laboratory of Lasers in Dentistry (LELO), School of DentistryUniversity of São Paulo (USP)São PauloBrazil
  3. 3.Department of Restorative Dentistry, School of DentistryUniversity of São Paulo (USP)São PauloBrazil
  4. 4.Lasers and Applications Center, Energy and Nuclear Research Institute (IPEN)University of São Paulo (USP)São PauloBrazil

Personalised recommendations