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.