, Volume 107, Issue 3, pp 285–290 | Cite as

Non-invasive analysis of bleaching effect of hydrogen peroxide on enamel by reflectance confocal microscopy (RCM): study of series of cases

  • Alfredo De Rosa
  • Dario Di StasioEmail author
  • Dorina Lauritano
  • Rossella Santoro
  • Andrea Marotta
  • Angelo Itro
  • Alberta Lucchese
Original Article


The aim of this study is to evaluate in vivo the effects of in-office tooth whitening hydrogen peroxide (HP) agent on enamel-microstructured surface by a reflectance confocal microscopy (RCM). Ten healthy volunteers assisted at the Dental School presenting teeth with vital pulp were selected. The 35% HP whiteness product was applied in two visits on discolored teeth, 1-week interval between, via 20-min applications. A commercially available hand-held RCM (Vivascope3000®, Lucid, Rochester, NY, USA) was used to image in vivo the dental surface of the selected tooth of each volunteer. Twenty upper central incisors’ vestibular surfaces were imaged, before bleaching (T0), immediately after (T1) and 1 week later (T2). The peculiar structure of the enamel was seen at T0. After bleaching, white reflective circular bodies were found all over the teeth surfaces, which disappear 1 week later (T2). When the HP gel® was imaged, the same white circular areas were observed. Going deeper, the regular enamel architecture was preserved. Textural analysis of the images in T0 and T2 was performed: GLCM parameters were extracted. Mann–Whitney U test was performed to evaluate statistical differences between two groups of data (p > 0.05). Finally, 35 prisms were randomly selected from T0 and T2 image and diameters were measured; a paired t test was performed (p = 0.381). The RCM is a promisor tool for investigating the features of enamel in vivo, immediately after bleaching procedures, as well as longitudinally.


Bleaching Hydrogen peroxide Confocal laser scanning microscopy In vivo imaging Image analysis 



We want to acknowledge all the patients involved in the present study for their kindly collaboration and indirect support to this study with their smiles. Conceived and designed the experiments: AL, DD, DA, IA. Performed the clinical examination: AL, DD, DA. Performed the experiments: AL, DD. Analyzed the data: AL, DD, DA, SR, MA. Wrote this paper: DD, DA, AL, SR, DL, IA. Performed the statistical analysis: DD.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


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Copyright information

© The Society of The Nippon Dental University 2019

Authors and Affiliations

  1. 1.Multidisciplinary Department of Medical-Surgical and Dental SpecialtiesUniversity of Campania Luigi VanvitelliNaplesItaly
  2. 2.Department of Medicine and SurgeryUniversity of Milano BicoccaMonzaItaly

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