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VOLUME 15 , ISSUE 2 ( March-April, 2014 ) > List of Articles


Fracture Resistance of Teeth Submitted to Several Internal Bleaching Protocols

Renato de Toledo Leonardo, Edson Alves de Campos, Katia Cristina Keine, Milton Carlos Kuga, Flávia Angélica Guiotti, Carolina Andolfatto, Norberto Batista de Faria-Júnior, Andrea Abi Rached Dantas

Citation Information : de Toledo Leonardo R, de Campos EA, Keine KC, Kuga MC, Guiotti FA, Andolfatto C, de Faria-Júnior NB, Dantas AA. Fracture Resistance of Teeth Submitted to Several Internal Bleaching Protocols. J Contemp Dent Pract 2014; 15 (2):186-189.

DOI: 10.5005/jp-journals-10024-1512

Published Online: 01-10-2014

Copyright Statement:  Copyright © 2014; The Author(s).



The aim of this study was to evaluate the fracture resistance of teeth submitted to several internal bleaching protocols using 35% hydrogen peroxide (35HP), 37% carbamide peroxide (37CP), 15% hydrogen peroxide with titanium dioxide nanoparticles (15HPTiO2) photoactivated by LED-laser or sodium perborate (SP).

Materials and methods

After endodontic treatment, fifty bovine extracted teeth were divided into five groups (n = 10): G1—unbleached; G2—35HP; G3—37CP; G4—15HPTiO2 photoactivated by LED-laser and G5—SP. In the G2 and G4, the bleaching protocol was applied in 4 sessions, with 7 days intervals between each session. In the G3 and G5, the materials were kept in the pulp teeth for 21 days, but replaced every 7 days. After 21 days, the teeth were subjected to compressive load at a cross head speed of 0.5 mm/min, applied at 135° to the long axis of the root using an eletromechanical testing machine, until teeth fracture. The data were submitted to ANOVA and Tukey tests (á = 5%).


The 35HP, 37CP, 15HPTiO2 and SP showed similar fracture resistance teeth reduction (p > 0.05). All bleaching treatments reduced the fracture resistance compared to unbleached teeth (p < 0.05).


All bleaching protocols reduced the fracture resistance of endodontically-treated teeth, but there were no differences between each other.

Clinical significance

There are several internal bleaching protocols using hydrogen peroxide in different concentrations and activation methods. This study evaluated its effects on fracture resistance in endodontically-treated teeth.

How to cite this article

de Toledo Leonardo R, Kuga MC, Guiotti FA, Andolfatto C, de Faria-Júnior NB, de Campos EA, Keine KC, Dantas AAR. Fracture Resistance of Teeth Submitted to Several Internal Bleaching Protocols. J Contemp Dent Pract 2014;15(2):186-189.

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