Photodynamic Therapy with a Photoactive Plant Extract Improves Gingival Health

Objectives: The hypothesis was that daily exposures of teeth and gingiva to photodynamic therapy comprising a light-emitting device and photoactive dental foam with an antimetabolic antibacterial botanical plant extract leads to a cumulative suppressive effect on bacteria and improved oral health. To test this hypothesis, a pilot study was conducted in subjects with gingivitis.
Methods: A 2-week, proof-of-concept, randomized, placebo-controlled, double-blind study included twenty subjects with existing gingivitis assigned to test or control (placebo) groups. Safety and efficacy measurements were performed at baseline, days 3, 7 and 14. Changes from baseline in gingival index (GI), bleeding on probing (BOP), and amount of plaque (PI) were assessed between- and within-groups at days 7 and 14. Bacterial killing was tested ex vivo using Live/Dead assay and flow cytometry. Supragingival microbial profiles were assessed by 16S rDNA sequencing using V1-V3 region. Safety assessments included oral exam, adverse events and presence or growth of candida in dental plaque and oral swab samples at Day 14. Statistical analyses were conducted using Mann-Whitney U test and paired t-test.

Results: Photodynamic therapy with photoactive foam (PT+PAF) significantly reduced BOP at both 7 and 14 days compared to control (p=0.001 and p=0.002, respectively) and was close-to-significance for a lower GI on both days (p=0.059). Although PI was similarly reduced in both groups, PT+PAF showed prominent bacterial killing capacity with a greater reduction in cell density compared to control [-16%±22.7% (reduction) versus 29%±28% (increase); p=0.07]. PT+PAF resulted in greater reductions in periodontopathogens and increases in health-associated species. No adverse events, oral irritation or adverse microbial (candida) growth were seen.

Conclusions: Results of this proof-of-concept study demonstrate that PT with a photoactive dental foam, as an additional measure for daily oral hygiene, has preventive and therapeutic potential for gingival inflammation.