Evaluation of adding nanosized natural zeolite to photodynamic therapy against P. gingivalis biofilm on titanium disks

Photodiagnosis Photodyn Ther. 2021 Dec;36:102519. doi: 10.1016/j.pdpdt.2021.102519. Epub 2021 Aug 31.


Background: Antibacterial photodynamic therapy (aPDT) can be used as an adjunctive therapy for eliminating bacterial biofilm. The application of nanotechnology in aPDT, which is a growing trend, has improved the delivery of photosensitizers (PSs) into microorganisms. Encapsulation of molecules and ions is considered an outstanding potential feature of zeolites. This study sought to enhance the effect of aPDT using a diode laser (810 nm) with a potential PS, indocyanine green (ICG), combined with nanosized natural zeolite (NZ), against biofilm of P. gingivalis on sandblasted, large-grit, and acid-etched (SLA) implant titanium disks surface.

Methods: A bacterial suspension of standard P. gingivalis (™ATCC® 33277) strains was prepared. To prepare bacterial biofilm, the titanium disks were added to 48 microtubes containing bacterial suspension, and divided into eight groups, i.e., the control groups (positive and negative), and 6 test groups (ICG; NZ; Diod laser; NZ+ICG; aPDT; NZ+aPDT). After the treatments, the total number of colony-forming units per disk was calculated. Finally, the data was analyzed, and the eight groups were compared together.

Results: The highest reduction in the number of P. gingivalis was seen in group 8 (NZ+aPDT) with 3.55 log10 CFU/ml and the antibacterial effect of 45.7% compared with the negative control group. Conversley, group 5 (Diode Laser solely) represented the highest mean of colony count with the lowest antibacterial effects per disk (6.42 log10 CFU/ml, 1.8%).

Conclusions: The antibacterial effect of NZ+aPDT against P. gingivalis biofilm was noticeable. Thus, adding NZ to ICG improved the result of aPDT in this study.

Keywords: Antimicrobial photodynamic therapy; Indocyanine green; Nanosized natural zeolite; Peri-implantitis.

MeSH terms

  • Biofilms
  • Photochemotherapy* / methods
  • Photosensitizing Agents / pharmacology
  • Titanium / pharmacology
  • Zeolites* / pharmacology


  • Photosensitizing Agents
  • Zeolites
  • Titanium