Comparative evaluation of LED- and diode laser-assisted in-office tooth whitening: a pilot randomized clinical study

BACKGROUND/OBJECTIVES: Light‐assisted in‐office whitening procedures are widely used in clinical practice; however, comparative clinical data remain limited, particularly when evaluated using objective outcome measures. This exploratory pilot randomized clinical trial aimed to generate preliminary comparative data on two commercially available light‐assisted in‐office tooth whitening protocols used under their respective manufacturers' clinical recommendations. The study also explored immediate color change, tooth sensitivity, and patient‐reported satisfaction to inform the design of future adequately powered randomized clinical trials. MATERIALS AND METHODS: Twelve healthy adult participants (18‐45 years) presenting extrinsic or mixed‐type tooth discoloration (baseline shade VITA A3 or darker) were randomly allocated into two parallel groups (n = 6 each). One group received whitening with a 35% hydrogen peroxide gel activated by a diode laser device, while the other group underwent whitening with a 25% hydrogen peroxide gel activated by an LED‐based device. Tooth color was measured before and immediately after treatment using a digital spectrophotometer (VITA Easyshade V), and color differences (ΔE) were calculated based on CIE L*a*b* coordinates. Post‐treatment tooth sensitivity was recorded using a Visual Analog Scale (VAS), and patient satisfaction was evaluated through a structured questionnaire. Statistical analysis was performed using the Mann‐Whitney U test. RESULTS: Both light‐assisted interventions resulted in clinically perceptible whitening outcomes (ΔE > 3.3). The LED‐assisted group showed a slightly higher median ΔE value (9.71 [IQR 7.64‐13.47]) compared with the laser‐assisted group (10.87 [IQR 8.91‐13.46]; however, the difference was not statistically significant ( Mann‐Whitney U test, p = 0.818). Tooth sensitivity scores were higher in the LED‐assisted group ( median 3.5 [IQR 3‐4]) compared to the diode laser‐assisted group (median 2.5 [IQR 2‐3]), but the difference did not reach statistical significance (p = 0.065). Patient‐reported satisfaction was high in both groups. CONCLUSIONS: Within the limitations of this exploratory pilot randomized clinical trial, both light‐assisted in‐office whitening protocols were associated with clinically perceptible immediate color changes. No statistically significant differences were detected between the investigated protocols; however, the limited sample size precludes definitive comparative conclusions. These findings should be considered preliminary and require confirmation in larger, adequately powered randomized clinical trials with longer follow‐up periods. TRIAL REGISTRATION: This study was registered in the ISRCTN clinical trial registry (ISRCTN62124700) on 24.01.2026.