Effects of an Experimental Propolis Gel on Tooth Sensitivity Control and Post-bleaching Color Change: a Randomized Clinical Trial

Effects of a 0.5% Experimental Propolis Gel on Tooth Sensitivity Control and Post-bleaching Color Change: a Randomized Clinical Trial

This randomized, parallel, double-blind, placebo-controlled clinical study aims to investigate the effects of an experimental 0.5% propolis gel on controlling tooth sensitivity and discoloration after in-office dental bleaching. Sixty-six volunteers will be selected according to inclusion and exclusion criteria and will be randomly assigned to three experimental groups: Placebo - received application of a gel without active ingredient (K-Y Original), KF2 - received application of 5% potassium nitrate and 2% sodium fluoride (Desensitize KF 2%), and Propolis 0.5% - application of the experimental 0.5% propolis gel. All participants will undergo two in-office bleaching sessions with 35% hydrogen peroxide, with seven-day intervals between them. The bleaching agent will be applied for 30 minutes. The desensitizing agents will be applied prior to bleaching and kept in contact with the vestibular dental surface for ten minutes. Sensitivity will be monitored daily using the Visual Analogue Scale for fourteen days, while color change will be determined by spectrophotometry, using the parameters of the CIELab* system and calculation of ΔE00, measured before bleaching (T0) and 7 days after the second bleaching session (T1). The data will be subjected to statistical analysis according to sample distribution, adopting a power of 80% and a significance level of 5%.

Study Overview

• Status: Not yet recruiting
• Conditions: Pain; Tooth Bleaching; Dentin Desensitizing Agents
• Intervention / Treatment: Other: Placebo - gel KY original; Other: KF2- Potassium nitrate; Other: Propolis gel

Detailed Description

All groups will undergo in-office whitening treatment, carried out in 2 sessions with a 7-day interval, according to the steps described below:

Prophylaxis; Application of gingival barrier; Application of desensitizing agent or placebo, according to the established groups; Handling of the whitening material following the manufacturer's instructions: application of Whiteness HP 35% whitening gel for 30 minutes Final removal of the whitening gel and gingival barrier, followed by rinsing with water.

The application of the desensitizing agent or its placebo will follow this sequence:

Relative isolation with cotton rolls; Active application of the product on the buccal surfaces of all teeth using a rubber cup for 10 minutes; Rinsing with water.

• Study Type: Interventional
• Enrollment (Estimated): 66
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Cecy M Silva, Doctor; Phone Number: +55 (91) 3201-7563; Email: cecymsilva@gmail.com

Study Locations

• Brazil
  • Pará
    • Belém, Pará, Brazil, 66075-110
      • UFPA
      • Contact: University F Para; Phone Number: 55(91) 3201-7390; Email: ppgo@ufpa.br

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• good oral hygiene
• absence of active caries lesions
• never having previous whitening therapy
• not present dental hypersensitivity
• don't be a smoker
• not be pregnant
• present at least 28 teeth in the oral cavity.

Exclusion Criteria:

• volunteers who were under orthodontic treatment,
• presence of periodontal disease
• dental cracks or fractures
• restorations and prostheses on anterior teeth
• extensive molar restorations
• gastroesophageal disorders
• severe internal dental darkening
• presence of dentinal exposure in anterior and/or posterior teeth.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo- KY original gel; The Placebo group received the application of placebo gel for post tooth bleaching sensitivity.	Other: Placebo - gel KY original; Prior to bleaching treatment with 35% hydrogen peroxide, the Placebo group received the application of a placebo gel (without active ingredient), under the same conditions described for the experimental gel.
Active Comparator: KF2- Potassium nitrate; The KF2 group received the application of potassium nitrate for post tooth bleaching sensitivity.	Other: KF2- Potassium nitrate; Prior to bleaching treatment with 35% hydrogen peroxide, the dental elements of the KF2 received application of the potassium nitrate gel on the buccal surfaces of the central incisors, lateral incisors, canines and upper and lower premolars, for 10 minutes.
Experimental: Propolis- Propolis 0,5% gel; The Propolis group received the application of experimental gel of propolis 0,5% for post tooth bleaching sensitivity.	Other: Propolis gel; Prior to bleaching treatment with 35% hydrogen peroxide, the dental elements of the Propolis received application of the experimental desensitizing gel on the buccal surfaces of the central incisors, lateral incisors, canines and upper and lower premolars, for 10 minutes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Post-whitening sensitivity assessment	To assess post-operative sensitivity, patients will be instructed to fill out a form to record daily tooth sensitivity during the 14 days of treatment, based on their individual perception of pain. This form will be handed out at each whitening session and returned to the researcher at the following session, that is, always one week after each whitening session. The assessment form will consist of a visual analogue scale (VAS). This scale consists of a 10 cm horizontal line with scores of 0 and 10 at its ends, where 0 means no sensitivity and 10 means severe tooth sensitivity. The patient will be instructed to draw a vertical line along the horizontal line of the scale, recording the intensity of tooth sensitivity per day. So that the distance in millimeters from the zero end can later be measured with the aid of a millimeter ruler, thus obtaining the patient's pain intensity level.	14 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Color evaluation	The VITA Easyshade spectrophotometer (VITA Zahnfabrik, Bad Säckingen, Germany) will be used to measure the color, where the area of dental correspondence to be evaluated will be the middle third of the vestibular surface of the upper canines. To standardize the color readings, silicone matrices will be made, where the impression will be extended from canine to canine. A window will be created on the vestibular surface of each canine of the silicone guide using a metal device with a radius of 6 mm, corresponding to the diameter of the spectrophotometer tip. Thus, the tip of the device will be inserted into the silicone guide to obtain the color parameters. Subsequently, the color difference between the baseline (T0) and one week after the 2rd bleaching session (T1) will be calculated using the CIEDE2000 formulas (ΔE00).	Baseline (T0) and one week after the 2rd whitening session (T1)

Collaborators and Investigators

• Sponsor: Universidade Federal do Para

Study record dates

Study Major Dates

• Study Start (Estimated): April 29, 2026
• Primary Completion (Estimated): December 30, 2026
• Study Completion (Estimated): March 30, 2027

Study Registration Dates

• First Submitted: April 29, 2026
• First Submitted That Met QC Criteria: April 29, 2026
• First Posted (Actual): May 6, 2026

Study Record Updates

• Last Update Posted (Actual): May 6, 2026
• Last Update Submitted That Met QC Criteria: April 29, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neurologic Manifestations; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain
• Other Study ID Numbers: 93881125.4.0000.0018

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No