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Not yet recruiting NCT07560761

Contribution of a* to Dental Bleaching After Combined Dental Bleaching

No phase Interventional Healthy

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
The protocol lists: Combined Dental Bleaching.
Who it may be relevant to
Registry conditions: Healthy. Basic parameters: 18 years — 65 years · All.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
Spain
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

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Official title

Contribution of the a* Parameter to Dental Bleaching After Combined Bleaching: A Prospective Non-randomized Single-arm Interventional Clinical Study

Overview

A prospective, non-randomized, single-arm interventional clinical study with a before-after design will be conducted to assess changes in CIELab color parameters and the Whiteness Index for Dentistry (WID) following a standardized combined dental bleaching protocol. The study aims to evaluate the contribution of the a\* parameter (green-red axis) to overall dental whiteness.

Detailed description

Tooth whitening is one of the most commonly requested aesthetic dental treatments, requiring objective and reproducible methods to quantify color changes. The CIELab color system (L\*, a\*, b\*) and the Whiteness Index for Dentistry (WID) are widely used for this purpose.

While increases in L\* and decreases in b\* are recognized as the main contributors to dental whitening, the role of the a\* parameter remains unclear. Variations in a\*, including the presence of negative values or changes in sign during treatment, have been insufficiently studied.

A prospective, non-randomized, single-arm interventional clinical study with a before-after design will be conducted to evaluate changes in L\*, a\*, b\*, and WID following a combined dental bleaching protocol consisting of an in-office phase with hydrogen peroxide and an at-home phase with carbamide peroxide.

Spectrophotometric measurements will be performed at baseline, after the in-office phase, and after completion of the at-home phase. The study will also analyze the relationship between changes in CIELab parameters and WID.

The study will be conducted in accordance with ethical standards and will be approved by the corresponding institutional review board. All participants will provide written informed consent prior to inclusion.

Interventions

  • Procedure Combined Dental Bleaching
    The intervention consists of an in-office bleaching phase with two 20-minute applications of 40% hydrogen peroxide, followed by an at-home bleaching phase using 16% carbamide peroxide applied with custom trays for 90 minutes daily. Treatment will continue until color stabilization is achieved, defined as a change in WID of less than 2.6 units between two consecutive weekly measurements.

Primary outcome measures

  • Change in Whiteness Index for Dentistry (WID) [Time frame: From baseline to end of treatment (up to 12 weeks).]
Secondary outcome measures (4)
  • Change in L* parameter [Time frame: Baseline to end of treatment (up to 12 weeks).]
  • Change in a* parameter [Time frame: Baseline to end of treatment (up to 12 weeks).]
  • Change in b* parameter [Time frame: Baseline to end of treatment (up to 12 weeks)]
  • Correlation between WID and CIELab parameters [Time frame: At end of treatment (up to 12 weeks).]

Eligibility criteria

Inclusion criteria

  • Age 18 to 65 years
  • Good oral health
  • Presence of natural anterior teeth (incisors, canines, premolars)
  • Anterior teeth without restorations
  • Indication for tooth bleaching treatment
  • Ability to comply with study procedures and visits

Exclusion criteria

  • Smoking
  • Previous tooth bleaching treatment
  • Pregnancy
  • Breastfeeding
  • Restorations in anterior teeth
  • Presence of diseases affecting tooth color
  • Conditions that may interfere with study outcomes

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation
N/A
Model
Single group
Masking
Open label
Primary purpose
Treatment

Study locations

Spain · 1 center
  • University of Valencia — Valencia

Publications

  • Perez Mdel M, Ghinea R, Rivas MJ, Yebra A, Ionescu AM, Paravina RD, Herrera LJ. Development of a customized whiteness index for dentistry based on CIELAB color space. Dent Mater. 2016 Mar;32(3):461-7. doi: 10.1016/j.dental.2015.12.008. Epub 2016 Jan 6. PMID 26778404

Identifiers

NCT: NCT07560761 · Bleaching_aStar_WID_2026 · Application Reference 2026-ODO

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗