Effect of peroxide bleaching on the biaxial flexural strength and modulus of bovine dentin

ABSTRACT

Objective: This study evaluated the effects of carbamide peroxide and hydrogen peroxide on the biaxial flexural strength and flexural modulus of bovine dentin. Materials and Methods: Thirty coronal dentin disks (0.5 mm thick × 6.0 mm diameter) were prepared from bovine teeth. The disks were randomly divided into three groups (n=10): A control group (unbleached), a group bleached with 10% carbamide peroxide (8 h at 37°C), and a group bleached with 38% hydrogen peroxide (three 10 min applications at 37°C). The specimens were tested in a biaxial flexural apparatus held in a universal testing machine at 1.27 mm/min until failure occurred, and the biaxial mechanical properties were calculated. For each test parameter, the data were statistically analyzed by Fisher's PLSD test (predetermined ⍺ = 0.05). Results: The group bleached with 38% hydrogen peroxide demonstrated significantly lower flexural strength than the unbleached control group. Hydrogen peroxide treatment resulted in a significantly lower flexural modulus compared with the control group and with carbamide peroxide bleaching. Conclusion: Exposure of dentin to hydrogen peroxide significantly reduced both the flexural strength and the flexural modulus compared with the no-treatment control, whereas exposure to carbamide peroxide did not significantly affect either parameter.

Key words:

Biaxial flexural strength - bleaching - carbamide peroxide - dentin - flexural modulus - hydrogen peroxide

• REFERENCES

• 1 Moghadam FV, Majidinia S, Chasteen J, Ghavamnasiri M. The degree of color change, rebound effect and sensitivity of bleached teeth associated with at-home and power bleaching techniques: A randomized clinical trial. Eur J Dent 2013; 7: 405-11
• 2 Alexandrino L, Gomes Y, Alves E, Costi H, Rogez H, Silva C. Effects of a bleaching agent with calcium on bovine enamel. Eur J Dent 2014; 8: 320-5
• 3 Joiner A. The bleaching of teeth: A review of literature. J Dent 2006; 34: 412-9
• 4 Kihn PW. Vital tooth whitening. Dent Clin North Am 2007; 51: 319-31 viii
• 5 Haywood VB, Heymann HO. Nightguard vital bleaching. Quintessence Int 1989; 20: 173-6
• 6 Seghi RR, Denry I. Effects of external bleaching on indentation and abrasion characteristics of human enamel in vitro . J Dent Res 1992; 71: 1340-4
• 7 Tam LE, Abdool R, El-Badrawy W. Flexural strength and modulus properties of carbamide peroxide-treated bovine dentin. J Esthet Restor Dent 2005; 17: 359-67
• 8 da Silva AP, de Oliveira R, Cavalli V, Arrais CA, Giannini M, de Carvalho RM. Effect of peroxide-based bleaching agents on enamel ultimate tensile strength. Oper Dent 2005; 30: 318-24
• 9 Piemjai M, Surakompontorn J. Effect of tooth-bleaching on the tensile strength and staining by caries detector solution on bovine enamel and dentin. Am J Dent 2006; 19: 387-92
• 10 Tam LE, Kuo VY, Noroozi A. Effect of prolonged direct and indirect peroxide bleaching on fracture toughness of human dentin. J Esthet Restor Dent 2007; 19: 100-9
• 11 Tam LE, Noroozi A. Effects of direct and indirect bleach on dentin fracture toughness. J Dent Res 2007; 86: 1193-7
• 12 Ghavamnasiri M, Abedini S, Mehdizadeh TazangiA. Effect of different time periods of vital bleaching on flexural strength of the bovine enamel and dentin complex. J Contemp Dent Pract 2007; 8: 21-8
• 13 Woo JM, Ho S, Tam LE. The effect of bleaching time on dentin fracture toughness in vitro . J Esthet Restor Dent 2010; 22: 179-84
• 14 Titley K, Torneck CD, Smith D. The effect of concentrated hydrogen peroxide solutions on the surface morphology of human tooth enamel. J Endod 1998; 14: 69-74
• 15 Gökay O, Müjdeci A, Algin E. In vitro peroxide penetration into the pulp chamber from newer bleaching products. Int Endod J 2005; 38: 516-20
• 16 Camargo SE, Valera MC, Camargo CH, Gasparoto ManciniMN, 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 Costa CA, Riehl H, Kina JF, Sacono NT, Hebling J. Human pulp responses to in-office tooth bleaching. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010; 109: e59-64
• 18 McGuckin RS, Babin JF, Meyer BJ. Alterations in human enamel surface morphology following vital bleaching. J Prosthet Dent 1992; 68: 754-60
• 19 Pinto CF, Oliveira Rd, Cavalli V, Giannini M. Peroxide bleaching agent effects on enamel surface microhardness, roughness and morphology. Braz Oral Res 2004; 18: 306-11
• 20 Berger SB, Cavalli V, Ambrosano GM, Giannini M. Changes in surface morphology and mineralization level of human enamel following in-office bleaching with 35% hydrogen peroxide and light irradiation. Gen Dent 2010; 58: e74-9
• 21 Berger SB, Cavalli V, Martin AA, Soares LE, Arruda MA, Brancalion ML. et al. Effects of combined use of light irradiation and 35% hydrogen peroxide for dental bleaching on human enamel mineral content. Photomed Laser Surg 2010; 28: 533-8
• 22 Dadoun MP, Bartlett DW. The microhardness of bleached dentine and its bond strength to a dentine bonding agent. Eur J Prosthodont Restor Dent 2007; 15: 131-4
• 23 Jiang T, Ma X, Wang Y, Zhu Z, Tong H, Hu J. Effects of hydrogen peroxide on human dentin structure. J Dent Res 2007; 86: 1040-5
• 24 Tam LE, Lim M, Khanna S. Effect of direct peroxide bleach application to bovine dentin on flexural strength and modulus in vitro . J Dent 2005; 33: 451-8
• 25 Toledano M, Yamauti M, Osorio E, Osorio R. Bleaching agents increase metalloproteinases-mediated collagen degradation in dentin. J Endod 2011; 37: 1668-72
• 26 Giannini M, Mettenburg D, Arrais CA, Rueggeberg FA. The effect of filler addition on biaxial flexure strength and modulus of commercial dentin bonding systems. Quintessence Int 2011; 42: e39-43
• 27 Kim BM, Eichler J, Reiser KM, Rubenchik AM, Da Silva LB. Collagen structure and nonlinear susceptibility: Effects of heat, glycation, and enzymatic cleavage on second harmonic signal intensity. Lasers Surg Med 2000; 27: 329-35
• 28 Lin PY, Lyu HC, Hsu CY, Chang CS, Kao FJ. Imaging carious dental tissues with multiphoton fluorescence lifetime imaging microscopy. Biomed Opt Express 2010; 2: 149-58
• 29 Tersariol IL, Geraldeli S, Minciotti CL, Nascimento FD, Pääkkönen V, Martins MT. et al. Cysteine cathepsins in human dentin-pulp complex. J Endod 2010; 36: 475-81
• 30 White DJ, Duschner H, Götz H. Effects of hydrogen peroxide bleaching strips on root surfaces in vitro . J Clin Dent 2007; 18: 87-90