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Evaluation of human enamel permeability exposed to bleaching agents

Abstract

AIM: To evaluate the human enamel permeability after different external bleaching techniques. METHODS: The coronal portions of 20 maxillary human incisors were covered with an acid resistant varnish, except the labial surface, to prevent dye penetration of silver nitrate. The specimens were divided randomly into four groups (n=5) according to the bleaching treatments: Group 1 (G1) - without bleaching agent (control group), Group 2 (G2) - 35% hydrogen peroxide (HP) - one session of three 10-min applications, Group 3 (G3) - 35% HP - 2 sessions of three 10-min applications, and Group 4 (G4) - 6% HP - 14 days (1h/day). G1 was exposed to artificial saliva only and in the other groups the bleaching agents were applied following the manufacturers' recommendations. After bleaching, teeth were immersed in a 50% silver nitrate solution for 2 h and photodeveloped for 16 h. Then, three longitudinal slices of each tooth were photographed by an optical microscope (100x). The degree of dye penetration was analyzed in the middle third of the dental crowns using a 0 to 4 score system (0= no dye penetration, 1= less than half the enamel thickness, 2= half of the enamel thickness, 3= full extent of enamel without reaching the dentin, and 4= tracer agent reaching dentin). The data were analyzed statistically by the Kruskal-Wallis and Dunn tests (α=0.05). RESULTS: The median (1st/3rd interquartiles) ranges were: G1: 0(0/0), G2: 2(2/3), G3: 3(3/3) and G4: 3(3/3). G2, G3 and G4 showed significantly higher dye penetration compared with G1 (p=0.0017). CONCLUSIONS: The use of bleaching agents increased dental enamel permeability, regardless of the bleaching technique.

dental enamel; bleaching agents; permeability


  • 1
    Tin-Oo MM, Saddki N, Hassan N. Factors influencing patient satisfaction with dental appearance and treatments they desire to improve aesthetics. BMC Oral Health. 2011; 11: 6
  • 2
    Haywood VB, Heymann HO. Nightguard vital bleaching. Quintessence Int. 1989; 20: 173-6.
  • 3
    Heymann HO. Tooth whitening: facts and fallacies. Brit Dent J. 2005; 198: 514.
  • 4
    Li Y. Safety controversies in tooth bleaching. Dent Clin N Am. 2011; 55: 255-63.
  • 5
    Haywood VB, Hook V, Heymann H. Nightguard vital bleaching effects of various solutions on enamel surface texture and color. Quintessence Int. 1991; 22: 775-82.
  • 6
    Al-Salehi SK, Wood DJ, Hatton PV. The effect of 24h non-stop hydrogen peroxide concentration on bovine enamel and dentin mineral content and microhardness. J Dent. 2007; 35: 845-50.
  • 7
    Cavalli V, Arrais CAG, Giannini M. Influence of low-concentrated bleaching agents on the human enamel roughness and morphology. ClipeOdonto - UNITAU. 2009; 1: 14-9.
  • 8
    Martin JM, De Almeida JB, Rosa EA, Soares P, Torno V, Rached RN, et al. Effects of fluoride therapies on the surface roughness of human enamel exposed to bleaching agents. Quintessence Int. 2010; 41: 71-8.
  • 9
    Bistey T, Nagy IP, Simó A, Hegedus C. In vitro FT-IR study of the effects of hydrogen peroxide on superficial tooth enamel. J Dent. 2007; 35: 325-30.
  • 10
    Sun L, Liang S, Sa Y, Wang Z, Ma X, Jiang T, et al. Surface alteration of human tooth enamel subjected to acidic and neutral 30% hydrogen peroxide. J Dent. 2011; 39: 686-92.
  • 11
    Sa Y, Chen D, Liu Y, Wen W, Xu M, Jiang T, et al. Effects of two in-office bleaching agents with different pH values on enamel surface structure and colour: an in situ vs. in vitro study. J Dent. 2012; 40: e26-34.
  • 12
    Minoux M, Serfaty R. Vital tooth bleaching: biologic adverse effects - a review. Quintessence Int. 2008; 39: 645-59.
  • 13
    Iwamoto N, Shimada Y, Tagami J. Penetration of silver nitrate into bleached enamel, dentin, and cementum. Quintessence Int. 2007; 38: e183-8.
  • 14
    Mendonça LC, Naves LZ, Garcia LFR, Correr-Sobrinho L, Soares CJ, Quagliatto PS. Permeability, roughness and topography of enamel after bleaching: tracking channels of penetration with silver nitrate. Braz J Oral Sci. 2011; 10: 1-6.
  • 15
    Krifka S, Börzsönyi A, Koch A, Hiller KA, Schmalz G, Friedl KH. Bond strength of adhesive systems to dentin and enamel-human vs. bovine primary teeth in vitro. Dent Mater. 2008; 24: 888-94.
  • 16
    Camargo SEA, Valera MC, Camargo CHR, Mancini MNG, Menezes MM. Penetration of 38% hydrogen peroxide into the pulp chamber in bovine and human teeth submitted to office bleach technique. J Endod. 2007; 33: 1074-7.
  • 17
    International Standardization for Organization. Guidance on testing of adhesion to tooth structure. Geneve, Switzerland; 2003. CD TR 11405.
  • 18
    Soares DGS, Ribeiro APD, Sacono NT, Coldebella CR, Hebling J, Souza Costa CA. Transenamel and transdentinal cytotoxicity of carbamide peroxide bleaching gels on odontoblast-like MDPC-23 cells. Int Endod J. 2011; 44: 116-25.
  • 19
    Freire A, Archegas LR, de Souza EM, Vieira S. Effect of storage temperature on pH of in-office and at-home dental bleaching agents. Acta Odontol Latinoam. 2009; 22: 27-31.
  • 20
    Spalding M, Taveira LA, De Assis GF. Scanning electron microscopy study of dental enamel surface exposed to 35% hydrogen peroxide: alone, with saliva, and with 10% carbamide peroxide. J Esthet Restor Dent. 2003; 15: 154-64.
  • 21
    de Oliveira MAVC, Quagliatto PS, Magalhães D, Biffi JCG. Effects of bleaching agents and adhesive systems in dental pulp: a literature review. Braz J Oral Sci. 2012; 11: 428-32.
  • 22
    Dias Ribeiro AP, Sacono NT, Lessa FCR, Nogueira I, Coldebella CR, Hebling J, et al. Cytotoxic effect of a 35% hydrogen peroxide bleaching gel on odontoblast-like MDPC-23 cells. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009; 108: 458-64.
  • 23
    Coldebella CR, Ribeiro APD, Sacono NT, Trindade FZ, Hebling J, Costa CAS. Indirect cytotoxicity of a 35% hydrogen peroxide bleaching gel on cultured odontoblast-like cells. Braz Dent J. 2009; 20: 267-74.
  • 24
    Dantas CMG, Vivan CL, Ferreira LS, Freitas PM, Marques MM. In vitro effect of low intensity laser on the cytotoxicity produced by substances released by bleaching gel. Braz Oral Res. 2010; 24: 460-6.
  • 25
    Chuang SF, Chen HP, Chang CH, Liu JK. Effect of fluoridated carbamide peroxide gels on enamel microtensile bond strength. Eur J Oral Sci. 2009; 117: 435-41.
  • 26
    Uysal T, Basciftci FA, Usumez S, Sari Z, Buyukerkmen A. Can previously bleached teeth be bonded safely? Am J Orthod Dentofacial Orthop. 2003; 123: 628-32.
  • 27
    Cavalli V, Reis AF, Giannini M, Ambrosano GM. The effect of elapsed times following bleaching on enamel bond strength of resin composite. Oper Dent. 2001; 26: 597-602.
  • 28
    Vongsavan N, Matthews B. The permeability of cat dentin in vivo and in vitro. Arch Oral Biol. 1991; 36: 641-6.
  • 29
    Berger SB, Pavan S, Dos Santos PH, Giannini M, Bedran-Russo AK. Effect of bleaching on sound enamel and with early artificial caries lesions using confocal laser microscopy. Braz Dent J. 2012; 23: 110-5.

Publication Dates

  • Publication in this collection
    19 July 2013
  • Date of issue
    June 2013

History

  • Received
    21 Mar 2013
  • Accepted
    25 June 2013
Faculdade de Odontologia de Piracicaba - UNICAMP Avenida Limeira, 901, cep: 13414-903, Piracicaba - São Paulo / Brasil, Tel: +55 (19) 2106-5200 - Piracicaba - SP - Brazil
E-mail: brjorals@unicamp.br