Efficacy and Safety Assessment of Experimental Bleaching Agents

Tooth whitening treatments are widely used to address dental discoloration. This study compares the efficacy of two experimental bleaching gels, Gel A (Carbomer 940 + 6% Hydrogen Peroxide) and Gel B (Hyaluronic Acid + 6% Hydrogen Peroxide), with and without 5% of NF_TiO₂ nanoparticles, and with and without light activation (405 nm, 30 min) versus a control bleaching product (Whiteness HP 35%, FGM). The aim is to evaluate tooth color change, sensitivity, and patient satisfaction in patients with baseline tooth discoloration ranging from shades A3 to C4 on the Vita Classical Shade Guide. Methods: This is a randomized controlled trial that will include 200 participants aged 18-65 years with mild to moderate tooth discoloration. Participants will be randomly assigned to one of 10 treatment groups: Gel A (with or without nanoparticles, with or without light), Gel B (with or without nanoparticles, with or without light), Whiteness HP 35% (with or without light) and Whiteness Automixx 6% (with or without light). The primary outcome is tooth color change, measured using the Vita EasyShade V system to assess ΔE, ΔE00, and Whiteness Index for Dentistry (WiD). Secondary outcomes will include tooth sensitivity (measured with a Visual Analog Scale) and patient satisfaction (assessed via post-treatment questionnaire). Randomization will be computer-generated, and the study will be double-blinded for evaluators. Results: The study is expected to detect significant differences in color change between the experimental gels and Whiteness HP 35%, with or without nanoparticles and light activation. Tooth sensitivity and patient satisfaction will be evaluated to determine the overall effectiveness and safety of the treatments. Conclusions: This trial will provide insights into the whitening efficacy of two experimental gels compared to a widely used commercial product. The inclusion of nanoparticles and light activation as variables will help determine the optimal conditions for effective tooth bleaching in patients with moderate discoloration. The results will contribute to evidence-based recommendations for aesthetic dental treatments.

• BLEACHING GEL A (Device): Carbomer 940 hydrogel + 6% Hydrogen Peroxide
• 5% NF_TiO2 (Device): Bioactive nanoparticles
• BLEACHING GEL B (Device): Hyaluronic Acid hydrogel + 6% Hydrogen Peroxide
• VISIBLE LIGHT IRRADIATION (Radiation): Low intensity visible light irradiation (405 nm)
• Whiteness HP 35% (Device): Commercially available bleaching gel
• Whiteness HP Automixx 6% (Device): Commercially available bleaching gel

Primary outcomes

• Tooth Color - Delta E [At baseline (T0), after each clinical session (T1, T2 and T3; 7 days interval between sessions) and at T4 (14 days after T3)]: Delta E ; This outcome measure is dimensionless and will be extracted from L*, a* and b* values.
• Tooth Color - Delta E00 [At baseline (T0), after each clinical session (T1, T2 and T3; 7 days interval between sessions) and at T4 (14 days after T3)]: Delta E00; This outcome measure is dimensionless and will be extracted from L*, a* and b* values.
• Tooth Color - WiD [At baseline (T0), after each clinical session (T1, T2 and T3; 7 days interval between sessions) and at T4 (14 days after T3)]: WiD; This outcome measure is dimensionless and will be extracted from L*, a* and b* values.

Secondary outcomes

• Tooth sensitivity [At baseline (T0), after each clinical session (T1, T2 and T3; 7 days interval between sessions) and at T4 (14 days after T3)]: Visual Analog Scale (VAS). The scale will vary from 0 (no pain) to 10 (worst pain possible). In this outcome measure, higher scores reflect outcomes that are worse in nature
• Patient Satisfaction [at T4 (14 days after T3)]: Post-treatment questionnaire.

Sex: All, ages: 18 Years to 65 Years, accepts healthy volunteers

Inclusion Criteria:

* Age: 18-65 years old.
* Healthy periodontal tissues.
* Willingness to participate and follow the post-treatment protocols.
* Ability to provide informed consent.
* Teeth having baseline colors ranging from shade A2 to C4

Exclusion Criteria:

* Pregnant or breastfeeding women.
* Teeth with restorations.
* History of dentin hypersensitivity.
* Active caries, periodontal disease or endodontically treated teeth.
* Use of substances that could affect tooth color during the trial, such as smoking and vaping.

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• Matos ICRT, Kury M, de Melo PBG, de Souza LVS, Esteban Florez FL, Cavalli V. Effects of experimental bleaching gels containing co-doped titanium dioxide and niobium pentoxide combined with violet light. Clin Oral Investig. 2023 Aug;27(8):4827-4841. doi: 10.1007/s00784-023-05113-z. Epub 2023 Jun 28. PMID 37369816
• Kury M, Esteban Florez FL, Tabchoury CPM, Cavalli V. Effects of experimental in-office bleaching gels incorporated with co-doped titanium dioxide nanoparticles on dental enamel physical properties. Odontology. 2025 Jan;113(1):318-330. doi: 10.1007/s10266-024-00976-4. Epub 2024 Jul 4. PMID 38963521
• Kury M, de Oliveira Ribeiro RA, de Souza Costa CA, Florez FLE, Cavalli V. Co-doped titanium dioxide nanoparticles decrease the cytotoxicity of experimental hydrogen peroxide gels for in-office tooth bleaching. Clin Oral Investig. 2024 Sep 25;28(10):550. doi: 10.1007/s00784-024-05916-8. PMID 39320486

• Fernando L Esteban Florez, D.D.S., M.S., Ph.D., Principal investigator, The University of Oklahoma Health Sciences Center College of Dentistry