Tooth Discoloration, Tooth Staining
Conditions
Keywords
dental bleaching, custom tray, 3D-printed tray, CAD-CAM, Carbamide peroxide, Nightguard vital bleaching, Tooth sensitivity, Gingival irritation, Spectrophotometer, Split-mouth trial, tooth whitening
Brief summary
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.
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.
Interventions
PROCEDURECustomized 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.
PROCEDUREReservoir 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.
At-home bleaching gel containing 10% carbamide peroxide applied in customized trays according to the study protocol
Sponsors
Universitat Internacional de Catalunya
Study design
Allocation
RANDOMIZED
Intervention model
FACTORIAL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Masking description
Participants and clinical outcome evaluators were unaware of group assignments. Data analysis was performed by a separate researcher who was not involved in treatment administration or outcome assessment. Due to the nature of tray fabrication and delivery, personnel involved in tray preparation may not have been blinded.
Intervention model description
This is a randomized split-mouth clinical trial. Each participant receives both tray fabrication methods (conventional vacuum-formed and digital 3D-printed CAD-CAM) in different arches, and both tray designs (with and without reservoirs) distributed across hemiarches according to randomized allocation. Therefore, within-participant comparisons are performed for tray fabrication method and reservoir presence.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
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)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Tooth color change (spectrophotometer; ΔE*ab) | 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. |
| Tooth shade change (VITA Bleachedguide 3D-MASTER; shade guide units) | 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
| Measure | Time frame | Description |
|---|---|---|
| Tooth sensitivity (Numeric Rating Scale, 0-4) | 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. |
| Tooth sensitivity (Visual Analog Scale, 0-10) | 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. |
| Gingival irritation presence (NRS, 0-2) | 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. |
| Gingival irritation severity (NRS, 0-2) | 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. |
| Patient comfort (VAS, 0-10) | 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. |
| Patient satisfaction with tooth color change (VAS, 0-10) | 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. |
Countries
Spain
Contacts
CONTACTMARTA VALLES, DDS, PhD
CONTACTLISSETHE PEÑATE, DDS, PhD
PRINCIPAL_INVESTIGATORMARTA VALLES, DDS, PhD
Universitat Internacional de Catalunya
Outcome results
None listed