Plaque control by dual-light photodynamic therapy in healthy adults - A randomized crossover pilot study

Twice-daily toothbrushing and flossing are standard oral hygiene practices, yet up to 50 % of plaque may remain even with proper technique. The home-use dual-light antibacterial photodynamic therapy (aPDT), consisting of 405 and 810 nm light, used together with indocyanine green photosensitizer, has emerged as a promising method to enhance plaque control. This study evaluated the efficacy of adjunctive daily ten-minute dual-light aPDT treatment in reducing dental plaque among healthy adults.

Thirty young healthy adults were randomly assigned to two groups in a six-week crossover design. Group 1 received two weeks of daily dual-light aPDT alongside conventional oral care, while Group 2 continued their regular oral care. After a two-week crossover phase, groups switched interventions. Plaque levels were measured at four time points using the Greene-Vermillion index.

At baseline, less plaque was observed in Group 1 (median [IQR] 1.0 [0.75-1-5]) than in Group 2 (1.0 [1.0-1.5]) (p = 0.026). After the first treatment phase, both Group 1 and Group 2 improved their oral hygiene 0.75 [0.5-1-0] (-28.4 %) and 1.0 [0.5-1.25] (-24.1 %), p < 0.0001 and p < 0.0001, respectively. During the second treatment phase, Group 2, which was now using aPDT, demonstrated a significant plaque reduction from 1.125 [0.94-1.5] to 0.75 [0.5-1.25] (-14.1 %) (p = 0.011), whereas Group 1 with standard treatment showed no statistical change, from 0.5 [0.44-0-81] to 0.63 [0.5-1.19] (+22.4) (p = 0.11). Pooled analysis revealed that the adjunct dual-light aPDT significantly reduced plaque compared to baseline, from 1.0 [1.0-1.5] to 0.5 [0.5-1.0] (-21.2 %)(p = 0.0001), while conventional care alone showed no significant change from 1.0 [0.5-1.5] to 1.0 [0.5-1.5] (-6.5%) (p = 0.11).

Daily use of dual-light aPDT as an adjunct to self-care significantly enhances plaque control beyond conventional toothbrushing and flossing, offering a potentially effective, non-invasive preventive strategy for maintaining oral hygiene in healthy adults.

This study shows that dual-light aPDT can serve as a clinically relevant adjunct to daily oral home care, enhancing plaque control even in individuals with good oral hygiene. It may be beneficial for patients with increased plaque-retentive challenges, including orthodontic appliances, implants, fixed prostheses, or reduced manual dexterity.