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.
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
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
Factorial
Customized bleaching tray fabrication
Procedure/SurgeryCustomized 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.
Reservoir tray design
Procedure/SurgeryTray designs were prepared either with a reservoir or without a reservoir, according to randomized allocation across hemiarches within the split-mouth design.
Carbamide peroxide 10%
DrugAt-home bleaching gel containing 10% carbamide peroxide applied in customized trays according to the study protocol
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.
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.
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.
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.
Gingival irritation presence (NRS, 0-2)
Gingival irritation presence assessed using a Numeric Rating Scale: 0 = absent, 1 = localized, 2 = generalized.
Gingival irritation severity (NRS, 0-2)
Gingival irritation severity assessed using a Numeric Rating Scale: 0 = no irritation, 1 = gingival burning, 2 = erosion.
Click on the lead sponsor to view all of their trials.
