Effectiveness of 16% Carbamide Peroxide in Reducing Hypersensitivity During Alternate-day Home Bleaching

September 28, 2025 updated by: Isabel Giráldez de Luis, Universidad Rey Juan Carlos

Efficacy in the Reduction of Hypersensitivity During Home Whitening With 16% Carbamide Peroxide Applied on Alternate Days: a Randomized Clinical Trial

The concentration of 16% carbamide peroxide is the highest concentration that European regulations allow for use in home whitening (Council directive 2011/84/EU). This concentration allows for faster results, but instead patients may suffer more frequently from dental sensitivity. The most commonly described side effect of all whitening procedures is the appearance of dentin hypersensitivity, hence the efforts to counteract or overcome this adverse effect.

The objective of the study is to clinically evaluate the difference in dental hypersensitivity produced by home dental whitening treatment using 16% carbamide peroxide in a tray for two hours daily applied daily or every other day for three weeks.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Volunteers will be instructed to use the whitening gel once a day for 2 hours, completing a total of 3 weeks of whitening procedure. Depending on the randomization, the bleaching procedure will be performed every other day or daily. In the upper arch, the teeth to be whitened will be from 15 to 25. The evaluations of efficacy, dental sensitivity and satisfaction will be carried out in the upper and lower arch. The color will be recorded before, weekly for 1 month, 6 months and 12 months after finishing the treatment. Shade assessment using the subjective method will be recorded with the Vita Classical color scale (Vita Zahnfabrik, Bad Säckingen, Germany), it will also be determined with the Vita 3D-MASTER scale (Vita Zahnfabrik, Bad Säckingen, Germany). For objective evaluation, the Vita Easyshade spectrophotometer (Vita Zahnfabrik, Bad Säckingen, Germany) will be used, according to the CIEL*a*b* system.

Study Type

Interventional

Enrollment (Actual)

110

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Spain
    • Madrid
      • Alcorcón, Madrid, Spain, 28922
        • Isabel Giraldez de Luis

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Patients older than 18 years.
  • Patients with vital teeth without restorations, single crowns, implants and/or bridges at the level of the anterior teeth.
  • Absence of cavities in the teeth to be whitened.
  • Patients with satisfactory oral hygiene and periodontally healthy, who are not undergoing periodontal maintenance and who do not use chlorhexidine mouthwashes. Patients with recessions without presenting sensitivity will be included.
  • Absence of sensitivity, measured with the application of air with the dental team's syringe.
  • Patients whose canines have at least an A2-A3 shade (VITA Classic® Guide).

Exclusion Criteria:

  • Patients who have previously undergone whitening (less than 5 years).
  • Patients undergoing orthodontic treatment.
  • Patients with white spots or alterations in the development of enamel or with stains.
  • Patients with a history of trauma to anterior teeth.
  • Patients who require internal whitening.
  • Smokers.
  • Pregnant or lactating.
  • Patients with allergies to any whitening component.
  • Patients presenting alterations of the oral mucosa (desquamative gingivitis, oral lichen planus, leukoplakia, etc.).
  • Patients with medical conditions considered by the researchers that may compromise the study or the individual safety of the patient.
  • Patients with poor oral hygiene.
  • Patients with previous hypersensitivity.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Daily whitening
Volunteers should whiten daily with a whitening tray from 15 to 25 and 35 to 45 for 2 hours. This procedure will last 3 weeks.
Other: Daily whitening
Daily application of a 16% carbamide peroxide bleaching gel in volunteers without sensitivity.
Experimental: Alternate whitening
Volunteers will bleach for 3 weeks with 16% carbamide peroxide, alternating one rest day for each placement day. They will wear a whitening tray from 15 to 25 and from 35 to 45 for 2 hours.
Other: Alternate whitening
Volunteers will apply the whitening gel at 16% carbamide peroxide, alternating a rest day with an application day. Patients should not be sensitive before starting the study.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Dental Sensitivity Visual Analog Scale (VAS) 0-10
Time Frame: 3 weeks
The aim of this study is to clinically evaluate the incidence of tooth sensitivity induced by home whitening with 16% carbamide peroxide applied in a tray for two hours daily or every other day for three weeks. For the assessment, the operators will apply air to the cervical area of the upper and lower canines and ask the patient if he/she experienced sensitivity at any time during the treatment.
3 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Whitening Efficacy CIEL*a*b*
Time Frame: 1 month
To assess whether the efficacy of the 16% carbamide peroxide bleaching treatment described above when used every other day is the same as when used every day, or whether there is a difference in bleaching efficacy. This will be determined at check-ups by measuring the upper and lower canines with the Vita EasyShade V® spectrophotometer, based on the CIEL*a*b* system, according to the CIELAB system, CIEDE2000 and the whiteness index. Where L* represents the value from 0 (black) to 100 (white) and a* and b* represent the colour, where a* is the measurement along the red-green axis and b* is the measurement along the yellow-blue axis. In addition, the operators will take shade readings on all 4 canines using the VITA Classical and 3D-MASTER guides.
1 month

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Gingival irritation VAS (0-10)
Time Frame: 3 weeks
Using the Visual Analogue Scale, compare the presence of gingival irritation after every other day bleaching with 16% carbamide peroxide compared to daily application. The patient should rate the gingival irritation experienced on a scale of 0 to 10, with 10 being very irritating and 0 being not irritating at all.
3 weeks
Patient's oral quality of life (OHIP-14)
Time Frame: 1 month
The impact of treatment outcome on the patient's oral quality of life (OHIP-14) will be assessed using a questionnaire after 16% carbamide peroxide home bleaching. The patient will complete a 14-question questionnaire on a daily basis, regardless of which group he/she belongs to, daily or alternate application.
1 month

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Universidad Rey Juan Carlos

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 6, 2024

Primary Completion (Actual)

February 27, 2025

Study Completion (Actual)

September 1, 2025

Study Registration Dates

First Submitted

September 6, 2023

First Submitted That Met QC Criteria

September 12, 2023

First Posted (Actual)

September 13, 2023

Study Record Updates

Last Update Posted (Estimated)

October 2, 2025

Last Update Submitted That Met QC Criteria

September 28, 2025

Last Verified

September 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • URJC University

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

The results obtained will only be shared once they have been published in an impact journal.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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