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Influence of Irrigation Protocol on Peroxide Penetration into Dentinal Tubules Following Internal Bleaching: A Confocal Laser Scanning Microscopy Study

  • Shlomo Elbahary1,*,
  • Zafrir Gitit2
  • Nurit Flaisher-Salem2
  • Hanaa Azem3
  • Hagay Shemsesh4,5
  • Eyal Rosen2
  • Igor Tsesis2

1Department of Endodontology and Pediatric Dentistry, Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel

2Department of Endodontology, Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel

3Department of Pediatric dentistry, Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel

4Department of Endodontology, Academic Centre of Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Amsterdam, The Netherlands

5Department of Endodontology, Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel

DOI: 10.17796/1053-4625-45.4.6 Vol.45,Issue 4,October 2021 pp.253-258

Published: 01 October 2021

*Corresponding Author(s): Shlomo Elbahary E-mail:


Introduction: Discoloration of anterior teeth can result in cosmetic impairment in young children. The walking bleach technique stands out because of its esthetic results with minor side effects. Little information is available regarding the influence of various irrigation solutions on peroxide penetration. The aim of this study is to evaluate the influence of different irrigation protocols on peroxide penetration into dentinal tubules using confocal laser scanning microscopy (CLSM).

Study design: Cavity preparations were made in 50 extracted permanent premolars. The teeth went through different irrigation sequences: A. control B. saline C. EDTA, NaOCl D. phosphoric acid E. EDTA, NaOCl, phosphoric acid. Then, mixture of fluorescent dyed sodium perborate paste was placed along the pulp chamber and the coronal access cavity, and was refilled at days 7, 14 and 21.

Results: The minimal and maximal penetration depths were 324 and 3045 μm, respectively, with a mean of 1607μm. The stained areas were significantly larger in the buccal and lingual directions (P<0.05). Groups B and C showed significantly larger penetration in weeks 2 and 3 compared to week 1 (P<0.05). Group D and E showed significantly larger penetration compared to groups B and C at all times (P<0.05).

Conclusion: Bleaching agents penetrate to the extra-radicular region of teeth; however, the level of peroxide penetration is significantly higher when the irrigation sequence consists of phosphoric acid prior the bleaching agent placement.


Discoloration; Bleaching; Sodium perborate; Peroxide; CLSM

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Shlomo Elbahary,Zafrir Gitit,Nurit Flaisher-Salem,Hanaa Azem,Hagay Shemsesh,Eyal Rosen,Igor Tsesis. Influence of Irrigation Protocol on Peroxide Penetration into Dentinal Tubules Following Internal Bleaching: A Confocal Laser Scanning Microscopy Study. Journal of Clinical Pediatric Dentistry. 2021. 45(4);253-258.


1. Plotino, G., Buono, L., Grande, N. M., Pameijer, C. H. & Somma, F. Nonvital Tooth Bleaching: A Review of the Literature and Clinical Procedures. J. Endod. 34, 394–407. 2008.

2. Sattapan, B. The endodontic management of a late complication of intrusive luxation injury. Aust. Endod. J. 24, 74–77.1998.

3. Rotstein, I., Lehr, Z. & Gedalia, I. Effect of bleaching agents on inorganic components of human dentin and cementum. J. Endod. 18, 290–293. 1992.

4. Flores-Mir, C., Silva, E., Barriga, M. I., Lagravère, M. O. & Major, P. W. Lay person’s perception of smile aesthetics in dental and facial views. J. Orthod. 31, 204–209. 2004.

5. Cortes, M. I. de S., Marcenes, W. & Sheiham, A. Impact of traumatic injuries to the permanent teeth on the oral health-related quality of life in

12- 14-year-old children. Community Dent. Oral Epidemiol. 30, 193–8. 2002.

6. Cortes, M. I. S., Marcenes, W. & Sheiham, A. Prevalence and correlates of traumatic injuries to the permanent teeth of school-children aged 9-14 years in Belo Horizonte, Brazil. Dent. Traumatol. 17, 22–26. 2001.

7. Gökay, O., Zıraman, F., Çalı Asal, A. & Saka, O. M. Radicular peroxide penetration from carbamide peroxide gels during intracoronal bleaching. Int. Endod. J. 41, 556–560 .2008.

8. MacIsaac, A. M. & Hoen, C. M. Intracoronal bleaching: concerns and considerations. J. Can. Dent. Assoc. 60, 57–64 .1994.

9. Friedman, S., Rotstein, I., Libfeld, H., Stabholz, A. & Heling, I. Incidence of external root resorption and esthetic results in 58 bleached pulpless teeth. Dent. Traumatol. 4, 23–26.1988.

10. Titley, K., Torneck, C. D. & Smith, D. The effect of concentrated hydrogen peroxide solutions on the surface morphology of human tooth enamel. J. Endod. 14, 69–74. 1988.

11. Pashley, D. H., Kepler, E. E., Williams, E. C. & Okabe, A. The effects of acid etching on the in-vivo permeability of dentine in the dog. Arch. Oral Biol. 28, 555–559 .1983.

12. Pashley, D. H., Michelich, V. & Kehl, T. Dentin permeability: Effects of smear layer removal. J. Prosthet. Dent. 46, 531–537 .1981.

13. Rotstein, I., Zalkind, M., Mor, C., Tarabeah, A. & Friedman, S. In vitro efficacy of sodium perborate preparations used for intracoronal bleaching of discolored non-vital teeth. Dent. Traumatol. 7, 177–180 .1991.

14. Madison, S. & Walton, R. Cervical Root Resorption following Bleaching of Endodontically Treated Teeth. J Endod. 16(12):570-4 .1990.

15. Trope, M. Cervcial Root Resorption. J. Am. Dent. Assoc. 128, 56S-59S .1997.

16. Perrine, G. A., Reichl, R. B., Baisden, M. K. & Hondrum, S. O. Comparison of 10% carbamide peroxide and sodium perborate for intracoronal bleaching. Gen. Dent. 48, 264–70 .2000.

17. Carrillo, A., Arredondo Trevino, M. V & Haywood, V. B. Simultaneous bleaching of vital teeth and an open-chamber nonvital tooth with 10%carbamide peroxide. Quintessence Int. 29, 643–8 .1998.

18. Weiger, R., Kuhn, A. & Löst, C. In vitro comparison of various types of sodium perborate used for intracoronal bleaching of discolored teeth. J. Endod. 20, 338–341 .199.).

19. Macey-Dare, L. V. & Williams, B. Bleaching of a discoloured non-vital tooth: use of a sodium perborate/water paste as the bleaching agent. Int. J. Paediatr. Dent. 7, 35–38 .2009.

20. Kaneko, J., Inoue, S., Kawakami, S. & Sano, H. Bleaching Effect of Sodium Percarbonate on Discolored Pulpless Teeth In Vitro. J. Endod. 26, 25–28 .2000.

21. Weiger, R., Kuhn, A. & Löst, C. Radicular penetration of hydrogen peroxide during intra-coronal bleaching with various forms of sodium perborate. Int. Endod. J. 27, 313–317 .1994.

22. Attin, T., Paque, F., Ajam, F. & Lennon, A. M. Review of the current status of tooth whitening with the walking bleach technique. Int. Endod. J. 36, 313–329 .2003.

23. Salvas, J. C. Perborate as a Bleaching Agent. J. Am. Dent. Assoc. Dent. Cosm. 25, 324 .1938.

24. Rotstein, I. In vitro determination and quantification of 30% hydrogen peroxide penetration through dentin and cementum during bleaching. Oral Surgery, Oral Med. Oral Pathol. 72, 602–606 .1991.

25. Camargo, S. E. A., Valera, M. C., Camargo, C. H. R., Gasparoto Mancini, M. N. & Menezes, M. M. Penetration of 38% Hydrogen Peroxide into the Pulp Chamber in Bovine and Human Teeth Submitted to Office Bleach Technique. J. Endod. 33, 1074–1077 .2007..

26. Gharib, S. R., Tordik, P. A., Imamura, G. M., Baginski, T. A. & Goodell, G. G. A Confocal Laser Scanning Microscope Investigation of the Epiphany Obturation System. J. Endod. 33, 957–961 .2007.

27. Chauhan, R., Tikku, A. & Chandra, A. Detection of residual obturation material after root canal retreatment with three different techniques using a dental operating microscope and a stereomicroscope: An in vitro comparative evaluation. J. Conserv. Dent. 15, 218–22 .2012.

28. Zapata, R. O. et al. Confocal Laser Scanning Microscopy Is Appropriate to Detect Viability of Enterococcus faecalis in Infected Dentin. J. Endod. 34, 1198–1201 .2008.

29. Kagayama, M., Sasano Y, Sato H, Kamakura S, Motegi K, Mizoguchi I.. Confocal microscopy of dentinal tubules in human tooth stained with aliz-arin red. Anat. Embryol. (Berl). 199, 233–238 .1999.

30. Patel, D. V., Sherriff, M., Ford, T. R. P., Watson, T. F. & Mannocci, F. The penetration of RealSeal primer and Tubliseal into root canal dentinal tubules: a confocal microscopic study. Int. Endod. J. 40, 67–71 .2007.

31. Tsesis, I., Elbahary, S., Venezia, N. B. & Rosen, E. Bacterial colonization in the apical part of extracted human teeth following root-end resection and filling: a confocal laser scanning microscopy study. Clin. Oral Investig. 22, 267–274 .2018.

32. Rosen, E., Tsesis, I., Elbahary, S., Storzi, N. & Kolodkin-Gal, I. Eradication of Enterococcus faecalis Biofilms on Human Dentin. Front. Microbiol. 7, 2055 .2016.

33. Kuçi, A., Alaçam, T., Yavaş, Ö., Ergul-Ulger, Z. & Kayaoglu, G. Sealer Penetration into Dentinal Tubules in the Presence or Absence of Smear Layer: A Confocal Laser Scanning Microscopic Study. J. Endod. 40, 1627–1631 .2014.

34. Tredwin, C. J., Naik, S., Lewis, N. J. & Scully, C. Hydrogen peroxide tooth-whitening (bleaching) products: Review of adverse effects and safety issues. Br. Dent. J. 200, 371–376 .2006.

35. Rotstein, I., Torek, Y. & Misgav, R. Effect of cementum defects on radicular penetration of 30% H2O2 during intracoronal bleaching. J. Endod. 17, 230–233 .1991.

36. Koulaouzidou, E., Lambrianidis, T., Beltes, P., Lyroudia, K. & Papadopoulos, C. Role of cementoenamel junction on the radicular penetration of 30% hydrogen peroxide during intracoronal bleaching in vitro. Dent. Traumatol. 12, 146–150 .1996.

37. Camps, J., de Franceschi, H., Idir, F., Roland, C. & About, I. Time-Course Diffusion of Hydrogen Peroxide Through Human Dentin: Clinical Significance for Young Tooth Internal Bleaching. J. Endod. 33, 455–459 2007.

38. Heithersay, G. S. Invasive cervical resorption: an analysis of potential predisposing factors. Quintessence Int. 30, 83–95 1999.

39. Cvek, M. & Lindvall, A.-M. External root resorption following bleaching of pulpless teeth with oxygen peroxide. Dent. Traumatol. 1, 56–60 .1985.

40. Bowles, W. H. & Ugwuneri, Z. Pulp chamber penetration by hydrogen peroxide following vital bleaching procedures. J. Endod. 13, 375–377 .1987.

41. Benetti, A. R., Valera, M. C., Mancini, M. N. G., Miranda, C. B. & Balducci, I. In vitro penetration of bleaching agents into the pulp chamber. Int. Endod. J. 37, 120–124 .2004.

42. Russell, A. A., Chandler, N. P., Hauman, C., Siddiqui, A. Y. & Tompkins, G. R. The Butterfly Effect: An Investigation of Sectioned Roots. J. Endod. 39, 208–210 .2013.

43. Vasiliadis, L., Darling, A. I. & Levers, B. G. H. The amount and distribution of sclerotic human root dentine. Arch. Oral Biol. 28, 645–649 .1983.

44. Lenherr, P., Allgayer N, Weiger R, Filippi A, Attin T, Krastl G. Tooth discoloration induced by endodontic materials: a laboratory study. Int. Endod. J. 45, 942–949 .2012.

45. Casey, L. J., Schindler, W. G., Murata, S. M. & Burgess, J. O. The use of dentinal etching with endodontic bleaching procedures. J. Endod. 15, 535–538 .1989.

46. Pashley, D. H., Kepler, E. E., Williams, E. C. & Okabe, A. The effects of acid etching on the in-vivo permeability of dentine in the dog. Arch. Oral Biol. 28, 555–559 .1983.

47. Burrow, M. Clinical evaluation of non-carious cervical lesion restorations using a HEMA-free adhesive: three-year results. Aust. Dent. J. 56, 401–405 .2011.

48. Kenny, D. J. New dental trauma guidelines for permanent teeth: a perspective. J. Can. Dent. Assoc. 78, c86 .2012..

49. Himel, V. T. & Alhadainy, H. A. Effect of dentin preparation and acid etching on the sealing ability of glass ionomer and composite resin when used to repair furcation perforations over plaster of paris barriers. J. Endod. 21, 142–145 .1995.

50. Walton, R. E., O’Dell, N. L., Lake, F. T. & Shimp, R. G. Internal bleaching of tetracycline-stained teeth in dogs. J. Endod. 9, 416–420 .1983.

51. Pashley, D. H., Kepler, E. E., Williams, E. C. & Okabe, A. The effects of acid etching on the in-vivo permeability of dentine in the dog. Arch. Oral Biol. 28, 555–559 .1983.

52. Pashley, D. H., Michelich, V. & Kehl, T. Dentin permeability: effects of smear layer removal. J. Prosthet. Dent. 46, 531–7 .1981.

53. Howell, R. A. Bleaching discoloured root-filled teeth. Br. Dent. J. 148, 159–162 .1980.

54. Dippel, H. W., Borggreven, J. M. & Hoppenbrouwers, P. M. Morphology and permeability of the dentinal smear layer. J. Prosthet. Dent. 52, 657–62 .1984.

55. Freccia, W. F., Peters, D. D., Lorton, L. & Bernier, W. E. An in vitro comparison of nonvital bleaching techniques in the discolored tooth. J. Endod. 8, 70–77 .1982.

56. Boksman, L., Jordan, R. E. & Skinner, D. H. Non-vital bleaching-internal and external. Aust. Dent. J. 28, 149–152 .1983.

61. Dietschi, D., Rossier, S. & Krejci, I. In vitro colorimetric evaluation of the efficacy of various bleaching methods and products. Quintessence Int. 37, 515–26.2006.

62. Valera, M. C., Camargo CHR., Carcalho CAT., Oliveira LD., Camargo SEA. Effectiveness of carbamide peroxide and sodium perborate in non-vital discolored teeth. J. Appl. Oral Sci. 17, 254–61 .2009.

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