Tooth bleaching is widely used to treat the colors of teeth. This study compares the efficiency of two experimental bleaching gels, with and without nanoparticles, and with and without light activation versus two commercial bleaching products of low and high concentrations. The objective is to evaluate tooth color change, sensitivity, and patient satisfaction in patients with moderate yellowing of their teeth. Methods: This is a randomized controlled trial that will include 120 participants aged 18-65 years. Participants will be randomly assigned to one of 12 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 a commercially-available equipment. Secondary outcomes will include tooth sensitivity and patient satisfaction. Randomization will be computer-generated. Results: The study is expected to show differences in color change between the experimental and commercial gels. Tooth sensitivity and patient satisfaction will be evaluated to determine the overall effectiveness and safety of the treatments. Conclusions: This trial will provide information into the whitening efficacy of two experimental gels compared to two widely used commercial products.

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.

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.

We will not share individual data. We plan on sharing data that have been statistically analyzed. The sharing of this data will occur via peer-reviewed publications and conferences such as the annual meetings of the American Association for Dental, Oral and Craniofacial Research, the International Association for Dental Research and the annual meeting of the Academy of Dental Materials.