Clinical and microbiological efficacy of indocyanine green-based antimicrobial photodynamic therapy as an adjunct to non-surgical treatment of periodontitis: a randomized controlled clinical trial

Objectives: The aim of the present randomized clinical trial (RCT) with a parallel arm design was to evaluate the clinical and microbiological efficacy of repeated ICG-aPDT as an adjunct to full-mouth subgingival debridement in the treatment of periodontitis. Materials and methods: Twenty-four periodontitis patients were treated with full-mouth ultrasonic subgingival debridement (FMUD). Initial sites with probing depth (PD) > 4 mm were randomly assigned to receive the test (ICG-aPDT with an 810 nm diode laser) or the control treatment (off-mode aPDT) one and four weeks after FMUD. Clinical parameters were registered after 3 and 6 months. The presence of the main periodontal pathogens in subgingival samples was assessed with real-time PCR. Results: Both treatment modalities resulted in significant clinical improvements at 3 and 6 months. The only significant differences in favour of the test group were found at 6 months for a higher PD reduction in initial deep pockets (PD ≥ 6 mm) and a higher percentage of closed pockets (PD ≤ 4 mm/no bleeding on probing). Limited microbiological changes were observed in both groups after treatment with no inter-group difference, except for a more significant reduction in Aggregatibacter actinomycetemcomitans and Parvimonas micra levels in the test group at 3 months. Conclusion: The combination of repeated ICG-aPDT and FMUD provided no benefits except for selective clinical and microbiological improvements compared to FMUD alone. Clinical relevance: Based on the obtained results, only limited adjunctive effects could be found for the combined use of ICG-aPDT and FMUD. Further, well-designed RCT with larger sample sizes are required to confirm these findings. Trial registration: ClinicalTrials.gov NCT04671394.