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

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

Study Overview

• Status: Recruiting
• Conditions: Tooth Discoloration; Tooth Staining
• Intervention / Treatment: Procedure: Customized bleaching tray fabrication; Procedure: Reservoir tray design; Drug: Carbamide peroxide 10%

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: MARTA VALLES, DDS, PhD; Phone Number: +34619747903; Email: mvalles@uic.es
• Study Contact Backup: Name: LISSETHE PEÑATE, DDS, PhD; Phone Number: +34 679 81 52 13; Email: lissethe@uic.es

Study Locations

• Spain
  • BARCELONA
    • Sant Cugat del Vallès, BARCELONA, Spain, 08195
      • Recruiting
      • Clínica Universitària d'Odontologia UIC Barcelona
      • Principal Investigator: MARTA VALLES, DDS, PhD
      • Contact: MARTA VALLES, Principal Investigator; Phone Number: 619747903; Email: mvalles@uic.es
      • Contact: LISSETHE PEÑATE, Sub Investigator; Email: lissethe@uic.es
      • Sub-Investigator: LISSETHE PEÑATE, DDS, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

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)

Study Plan

How is the study designed?

Design Details

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

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Digital tray with reservoir; Customized digital (3D-printed CAD-CAM) bleaching tray with reservoir design for at-home bleaching with 10% carbamide peroxide.	Procedure: Customized bleaching tray fabrication; 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; Procedure: Reservoir tray design; 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; Drug: Carbamide peroxide 10%; At-home bleaching gel containing 10% carbamide peroxide applied in customized trays according to the study protocol; Other Names: 10% carbamide peroxide bleaching gel
Experimental: Digital tray without reservoir; Customized digital (3D-printed CAD-CAM) bleaching tray without reservoir design for at-home bleaching with 10% carbamide peroxide.	Procedure: Customized bleaching tray fabrication; 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; Procedure: Reservoir tray design; 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; Drug: Carbamide peroxide 10%; At-home bleaching gel containing 10% carbamide peroxide applied in customized trays according to the study protocol; Other Names: 10% carbamide peroxide bleaching gel
Experimental: Conventional tray with reservoir; Customized conventional vacuum-formed bleaching tray with reservoir design for at-home bleaching with 10% carbamide peroxide.	Procedure: Customized bleaching tray fabrication; 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; Procedure: Reservoir tray design; 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; Drug: Carbamide peroxide 10%; At-home bleaching gel containing 10% carbamide peroxide applied in customized trays according to the study protocol; Other Names: 10% carbamide peroxide bleaching gel
Experimental: Conventional tray without reservoir; Customized conventional vacuum-formed bleaching tray without reservoir design for at-home bleaching with 10% carbamide peroxide.	Procedure: Customized bleaching tray fabrication; 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; Procedure: Reservoir tray design; 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; Drug: Carbamide peroxide 10%; At-home bleaching gel containing 10% carbamide peroxide applied in customized trays according to the study protocol; Other Names: 10% carbamide peroxide bleaching gel

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Tooth color change (spectrophotometer; ΔE*ab)	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.	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 change (VITA Bleachedguide 3D-MASTER; shade guide units)	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.	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).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Tooth sensitivity (Numeric Rating Scale, 0-4)	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.	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 (Visual Analog Scale, 0-10)	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.	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 (NRS, 0-2)	Gingival irritation presence assessed using a Numeric Rating Scale: 0 = absent, 1 = localized, 2 = generalized.	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 (NRS, 0-2)	Gingival irritation severity assessed using a Numeric Rating Scale: 0 = no irritation, 1 = gingival burning, 2 = erosion.	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 (VAS, 0-10)	Patient comfort assessed using a Visual Analog Scale (VAS): 0 = no comfort, 10 = high comfort.	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 with tooth color change (VAS, 0-10)	Patient satisfaction (acceptance) with tooth color changes assessed using a Visual Analog Scale (VAS): 0 = least satisfaction, 10 = most satisfaction.	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).

Collaborators and Investigators

• Sponsor: Universitat Internacional de Catalunya
• Investigators: Principal Investigator: MARTA VALLES, DDS, PhD, Universitat Internacional de Catalunya

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2022
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): July 1, 2026

Study Registration Dates

• First Submitted: February 25, 2026
• First Submitted That Met QC Criteria: March 5, 2026
• First Posted (Actual): March 11, 2026

Study Record Updates

• Last Update Posted (Actual): March 16, 2026
• Last Update Submitted That Met QC Criteria: March 11, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: CAD-CAM; Tooth sensitivity; dental bleaching; tooth whitening; Carbamide peroxide; Spectrophotometer; Gingival irritation; Split-mouth trial; custom tray; 3D-printed tray; Nightguard vital bleaching
• Additional Relevant MeSH Terms: Stomatognathic Diseases; Tooth Diseases; Dentin Sensitivity; Tooth Discoloration
• Other Study ID Numbers: REST-ECL-2021-06

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data (IPD) will not be shared because the dataset contains potentially identifiable clinical information from a small sample treated at a single center, and no data-sharing plan was included in the original participant consent.

Drug and device information, study documents

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