Effectiveness of Sealed In-office Bleaching Technique: Randomized Controlled Clinical Trial
Condition: Tooth Discoloration
MeSH terms: Tooth Discoloration
Study type: Interventional

Summary: 
      Thus, the aim of this study is to evaluate the sealed bleaching technique on tooth
      sensitivity and bleaching efficacy. The hypothesis is that the sealed bleaching technique
      reduce the tooth sensitivity when compared to conventional technique, without alters the
      bleaching efficacy.
    

Detailed description: 
      This is a randomized, single-blind, and controlled trial with a parallel group and an equal
      allocation rate to receive either one of two treatments, whereas the sealed technique is the
      experimental intervention and the conventional technique is control one.

      PICO Question:

      P (Population) - Patients of dentistry service of Federal University of Sergipe.

      I: (Intervention) - In-office bleaching using 35% hydrogen peroxide bleaching agent covered
      with a customized tray.

      C: (Control) - In-office bleaching using 35% hydrogen peroxide bleaching agent covered
      without a customized tray.

      O: (Outcomes) - Primary outcomes: presence of tooth sensitivity during the bleaching
      procedure; Secondary outcome: Bleaching efficacy.

      Sample Patients attempted in clinical service of Federal University of Sergipe requiring
      tooth bleaching will be recruited for this trial. For sample size calculation was considered
      80% of test power, significance level of 5%, the presence of tooth sensitivity of 90% at
      control intervention and 40% at experimental intervention. These levels of sensitivity were
      based in pilot study. Thus the sample size for a proportions test (SigmaStat 3.5 (Systat
      Software, Point Richmond, USA) was 17 participants for each intervention.

      Randomization Previously to beginning of study, a blocked randomisation list will be created
      using the website www.sealedenvelope.com, using block size of 4, by an operator different
      from those who will be perform the bleaching procedures. The bleaching protocol for each
      participant will be placed into a sealed envelope, while this only will be opened in the
      moment of bleaching procedure.

      Evaluations During the permanence of bleaching agent, the tooth sensitivity will be monitored
      and the scores (VAS and verbal scale) will be recorded at 20th and 40th minute. The score
      also will be recorded immediately after the bleaching agent removal. In the after day, the
      participants will be argued (only verbal scale) about the maximum level of sensitivity during
      the first 24 hours after bleaching procedure and in 24th hour after this. A week after the
      bleaching procedure, the scores based on shade guides will be recorded again. For CIE L*a*b*
      measurement, ΔE will be calculated by the following equation: ∆E= [(∆L)2 + (∆a)2 + (∆b)2]1/2,
      while ∆L = L1 - L0; ∆a = a1 - a0; e ∆b = b1 - b0. After the shade evaluation, a new bleaching
      procedure, using the same protocol, will be performed in this second appointment and the same
      measurements of tooth sensitivity will be performed similarly to first one. After a week of
      second session, only the shade will be evaluated.

      Blinding Once that it is not possible to blind the operators responsible by bleaching
      procedures and the participants, only the operators responsible by evaluations and by
      statistical analysis will be blinded.

      Analysis of data The average of scores corresponding to shade guides will be calculated for
      each participant in the three moments of evaluation. Data will be submitted to Friedman and
      Man-Whitney tests. The average of ∆E will be calculated for each participant in the two
      moments of re-evaluation, while the data will be submitted to two-way ANOVA (protocol x
      moment of evaluation). Data for tooth sensitivity scores will be submitted to Friedman and
      Man-Whitney tests. The multiple-comparison test of Tukey will be used when necessary. The
      number of participants presenting any sensitivity during each session of bleaching will be
      calculated, while the percentage of these participants for each protocol will be calculated
      using Chi-square test. All statistical analysis will be performed with significant level of
      5%.
    

Intervention name(s): Tooth bleaching
Intervention type(s): Drug
Intervention description(s): The bleaching agent will be used in a single-application of 45 minutes.
Other intervention name(s): 35% hydrogen peroxide based bleaching agent, Whiteness HP Maxx, FGM, Joinville, SC, Brazil.
Intervention MeSH terms: Hydrogen Peroxide
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Tooth Discoloration; Bleaching Agents; Tooth Bleaching