Tooth bleaching increases dentinal protease activity

C. Sato, F. A. Rodrigues, D. M. Garcia, C. M.P. Vidal, David Henry Pashley, L. Tjäderhane, M. R. Carrilho, F. D. Nascimento, I. L.S. Tersariol

Research output: Contribution to journalArticlepeer-review

54 Scopus citations


Hydrogen peroxide is an oxidative agent commonly used for dental bleaching procedures. The structural and biochemical responses of enamel, dentin, and pulp tissues to the in vivo bleaching of human (n = 20) premolars were investigated in this study. Atomic force microscopy (AFM) was used to observe enamel nanostructure. The chemical composition of enamel and dentin was analyzed by infrared spectroscopy (FTIR). The enzymatic activities of dental cathepsin B and matrix metalloproteinases (MMPs) were monitored with fluorogenic substrates. The amount of collagen in dentin was measured by emission of collagen autofluorescence with confocal fluorescence microscopy. The presence of Reactive Oxygen Species (ROS) in the pulp was evaluated with a fluorogenic 2′,7′-dichlorodihydrofluorescein diacetate (DCFDA) probe. Vital bleaching of teeth significantly altered all tested parameters: AFM images revealed a corrosion of surface enamel nanostructure; FTIR analysis showed a loss of carbonate and proteins from enamel and dentin, along with an increase in the proteolytic activity of cathepsin-B and MMPs; and there was a reduction in the autofluorescence of collagen and an increase in both cathepsin-B activity and ROS in pulp tissues. Together, these results indicate that 35% hydrogen peroxide used in clinical bleaching protocols dramatically alters the structural and biochemical properties of dental hard and soft pulp tissue.

Original languageEnglish (US)
Pages (from-to)187-192
Number of pages6
JournalJournal of Dental Research
Issue number2
StatePublished - Feb 2013


  • FTIR
  • collagen
  • confocal microscopy
  • cysteine proteases
  • matrix metalloproteinase
  • tooth bleaching

ASJC Scopus subject areas

  • Dentistry(all)


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