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Evaluation of in-office tooth whitening treatment with violet LED: protocol for a randomised controlled clinical trial
  1. Ana Eliza Castanho Garrini dos Santos1,
  2. Sandra Kalil Bussadori1,2,
  3. Marcelo Mendes Pinto3,
  4. Dácio Antonio Pantano Junior3,
  5. Aldo Brugnera Jr4,
  6. Fátima Antonia Aparecida Zanin5,
  7. Maria Fernanda Setúbal Destro Rodrigues1,
  8. Lara Jansiski Motta1,6,
  9. Anna Carolina Ratto Tempestini Horliana1
  1. 1 Postgraduate Program in Biophotonics Appliedto Health Sciences, Nove de Julho University, São Paulo, Brazil
  2. 2 Postgraduate Program in Rehabilitation Sciences, Universidade Nove de Julho, UNINOVE, São Paulo, Brazil
  3. 3 School of Dentistry, Universidade Nove de Julho, UNINOVE, São Paulo, Brazil
  4. 4 IFSC (Phisics Institute of São Carlos)
  5. 5 Brugnera and Zanin Biophotonic Center Institute, São Paulo, Brazil
  6. 6 Nove de Julho University, São Paulo, Brazil
  1. Correspondence to Dr Anna Carolina Ratto Tempestini Horliana; annacrth{at}


Introduction In-office tooth whitening treatment using violet light emited diode (LED) (405 nm) is a novel bleaching method that causes less sensitivity while offering the same effectiveness as the gold standard (35% hydrogen peroxide, H2O2). This study describes a protocol for the first randomised controlled clinical trial to compare the effects of the two methods.

Methods and analysis Eighty patients will be divided into four groups: G1 violet LED; G2 violet LED +35% carbamide peroxide; G3 35% H2O2 and G4 violet LED +gingivoplasty. Colour will be measured at baseline, immediately after the first session and at the 15 and 180 days follow-up using the Vita Classical and the digital Easyshade V spectrophotometer (Vita, Zahnfabrik, Germany). Sensitivity after whitening will be measured using the Visual Analogue Scale at baseline and at each session in all groups and in all follow-ups. The tissue removed during gingivoplasty (G4) will be submitted to immunohistochemical analysis for the determination of inflammatory changes caused by violet LED. The Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) will be evaluated before, as well as at established time point controls. The results will be expressed as mean and SD values. After determining the normality of the data, a one-way repeated-measures analysis of variance will be used for the comparison of data with normal distribution and the Kruskal-Wallis test will be used for data with non-normal distribution. A p<0.05 will be considered indicative of statistical significance. After determining the normality of the data, the Kruskal-Wallis test will be used for non-parametric data. Multivariate analysis of variance (MANOVA) and the Wilcoxon test will be used for comparing data from the PIDAQ.

Ethics and dissemination This protocol has been approved by the Human Research Ethics Committee of UniversidadeNove de Julho (certificate: 2.034.518). The findings will be published in a peer-reviewed journal.

Trial registration number NCT03192852; Pre-results.

  • tooth bleaching
  • dental aesthetics
  • clinical trial
  • violet led
  • sensitivity

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  • Contributors AECGdS and MMP made substantial contributions to the conception and design of the study as well as the acquisition, analysis and interpretation of the data. SKB, DAP, AB, FAAZ, MFSDR and LJM involved in drafting the manuscript and revising it critically for important intellectual content. ACRTH gave final approval of the version to be published.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent Obtained.

  • Ethics approval The UNINOVE Human Research Ethics Committee ( (#2.034.518).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Author note Only principal investigators (authors of this paper) will be given full access to the cleaned data sets. Project data sets will be saved on the computer of Biophotonics Applied to Health Sciences, Universidade Nove de Julho, UNINOVE, R. Vergueiro, 235/249, CEP 01504-001- São Paulo, SP, Brazil. Phone: +55 (11) 33859222 and all data sets will be protected by password.

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