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NCT Number: NCT07464197

Effectiveness of Dental Bleaching Using Different Designs of 3D-Printed and Conventional Customized Nightguards

This randomized, double-blind, split-mouth clinical trial evaluates the effectiveness of at-home dental bleaching using customized nightguards fabricated by digital (3D-printed CAD-CAM) and conventional methods, with and without reservoirs. Adult participants with good general and oral health and a baseline tooth shade of A2 or darker undergo bleaching with 10% carbamide peroxide. Outcomes include tooth color change (subjective and spectrophotometric measures), tooth sensitivity, gingival irritation, patient comfort, and patient satisfaction over time.

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Key information

Conditions

Tooth Discoloration Dentin Sensitivity Stomatognathic Diseases Tooth Diseases Tooth Staining

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Clínica Universitària d'Odontologia UIC Barcelona

Sant Cugat del Vallès, BARCELONA, 08195, Spain

Location status: Recruiting

About this study

This study compares the effectiveness of at-home dental bleaching using customized conventional vacuum-formed trays and digitally fabricated (3D-printed CAD-CAM) trays. It also compares tray designs with and without reservoirs using a randomized split-mouth design.

Each participant receives both tray fabrication approaches and both reservoir conditions, distributed according to randomized allocation. Bleaching is performed with 10% carbamide peroxide. Participants are followed during and after treatment to assess tooth color change, tooth sensitivity, gingival irritation, comfort, and satisfaction.

Tooth color is assessed using both visual and spectrophotometric methods. A customized positioner is used to standardize the measurement location throughout the study.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adults aged 18 years or older
  • Good general and oral health
  • No current medical treatment (self-reported)
  • No need for surgical, endodontic, periodontal, or restorative dental treatment
  • At least six upper and six lower anterior teeth free of caries and restorations
  • Maxillary central incisors with baseline shade A2 or darker
  • Willingness to follow the study protocol and use the study-provided oral hygiene products/instructions

Exclusion criteria

  • Previous tooth bleaching treatment
  • Orthodontic appliances or prostheses that interfere with treatment
  • Severe intrinsic discoloration (e.g., tetracycline staining, fluorosis, or endodontically treated teeth with discoloration)
  • Pregnancy or lactation
  • Bruxism
  • Gingival recession, dentin exposure, visible enamel cracks, or other conditions associated with increased sensitivity
  • Use of anti-inflammatory or analgesic medication during the study period (according to protocol)

Treatment and study plan

Customized bleaching tray fabrication

Procedure

Customized bleaching trays were fabricated using either a conventional vacuum-forming technique or a digital CAD-CAM 3D-printing technique, according to randomized allocation within a split-mouth design.

Other names: Conventional vacuum-formed tray fabrication, Digital 3D-printed CAD-CAM tray fabrication

Reservoir tray design

Procedure

Tray designs were prepared either with a reservoir or without a reservoir, according to randomized allocation across hemiarches within the split-mouth design.

Other names: With reservoir, Without reservoir

Carbamide peroxide 10%

Drug

At-home bleaching gel containing 10% carbamide peroxide applied in customized trays according to the study protocol

Other names: 10% carbamide peroxide bleaching gel

Primary outcomes

  1. Tooth color change (spectrophotometer; ΔE*ab)

    Time frame: T0 (baseline, Day 0); T1 (Week 1); T2 (Week 2); T3 (Week 3); T4 (Week 4); T5 (Week 6, end of bleaching); T6 (Week 8, 2 weeks post-bleaching).

    Tooth color measured with a spectrophotometer (VITA Easyshade) using CIE L*, a*, b* values. Color change will be calculated as ΔE*ab relative to baseline (T0). Measurements are standardized using a customized positioner. Bleaching was performed from T0 through T5. No bleaching gel was applied between T5 and T6; T6 assessed post-treatment stability and adverse effects.

  2. Tooth shade change (VITA Bleachedguide 3D-MASTER; shade guide units)

    Time frame: T0 (baseline, Day 0); T1 (Week 1); T2 (Week 2); T3 (Week 3); T4 (Week 4); T5 (Week 6, end of bleaching); T6 (Week 8, 2 weeks post-bleaching).

    Tooth shade assessed visually using the VITA Bleachedguide 3D-MASTER. Shade guide scores will be converted to numeric values and reported as change from baseline (T0) at each time point. Bleaching was performed from T0 through T5. No bleaching gel was applied between T5 and T6; T6 assessed post-treatment stability and adverse effects.

Secondary outcomes

  1. Tooth sensitivity (Numeric Rating Scale, 0-4)

    Time frame: T0 (baseline, Day 0); T1 (Week 1); T2 (Week 2); T3 (Week 3); T4 (Week 4); T5 (Week 6, end of bleaching); T6 (Week 8, 2 weeks post-bleaching).

    Tooth sensitivity assessed using a 5-point Numeric Rating Scale (NRS): 0 = none, 1 = slight, 2 = moderate, 3 = considerable, 4 = severe. For each visit, the worst (highest) NRS value reported at that assessment point will be used for analysis. Bleaching was performed from T0 through T5. No bleaching gel was applied between T5 and T6; T6 assessed post-treatment stability and adverse effects.

  2. Tooth sensitivity (Visual Analog Scale, 0-10)

    Time frame: T0 (baseline, Day 0); T1 (Week 1); T2 (Week 2); T3 (Week 3); T4 (Week 4); T5 (Week 6, end of bleaching); T6 (Week 8, 2 weeks post-bleaching).

    Tooth sensitivity assessed using a 10-cm Visual Analog Scale (VAS) from 0 (no sensitivity) to 10 (severe sensitivity). For each visit, the highest VAS value reported at that assessment point will be used for analysis. Bleaching was performed from T0 through T5. No bleaching gel was applied between T5 and T6; T6 assessed post-treatment stability and adverse effects.

  3. Gingival irritation presence (NRS, 0-2)

    Time frame: T0 (baseline, Day 0); T1 (Week 1); T2 (Week 2); T3 (Week 3); T4 (Week 4); T5 (Week 6, end of bleaching); T6 (Week 8, 2 weeks post-bleaching).

    Gingival irritation presence assessed using a Numeric Rating Scale: 0 = absent, 1 = localized, 2 = generalized.

  4. Gingival irritation severity (NRS, 0-2)

    Time frame: T0 (baseline, Day 0); T1 (Week 1); T2 (Week 2); T3 (Week 3); T4 (Week 4); T5 (Week 6, end of bleaching); T6 (Week 8, 2 weeks post-bleaching).

    Gingival irritation severity assessed using a Numeric Rating Scale: 0 = no irritation, 1 = gingival burning, 2 = erosion.

  5. Patient comfort (VAS, 0-10)

    Time frame: T0 (baseline, Day 0); T1 (Week 1); T2 (Week 2); T3 (Week 3); T4 (Week 4); T5 (Week 6, end of bleaching); T6 (Week 8, 2 weeks post-bleaching).

    Patient comfort assessed using a Visual Analog Scale (VAS): 0 = no comfort, 10 = high comfort.

  6. Patient satisfaction with tooth color change (VAS, 0-10)

    Time frame: T0 (baseline, Day 0); T1 (Week 1); T2 (Week 2); T3 (Week 3); T4 (Week 4); T5 (Week 6, end of bleaching); T6 (Week 8, 2 weeks post-bleaching).

    Patient satisfaction (acceptance) with tooth color changes assessed using a Visual Analog Scale (VAS): 0 = least satisfaction, 10 = most satisfaction.

Interested in participating?

Recruiting

Interested in participating?

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Sponsors and collaborators

Lead sponsor

Universitat Internacional de Catalunya

Other

Registry information

Official study title

Evaluation of the Effectiveness in Dental Bleaching by Different Designs of 3D-Printed Digital Customized Nightguards

Important dates

Study start
2022
Primary completion
2026
Study completion
2026
First posted
Mar 11, 2026
Registry last updated
Mar 16, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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