Dose Parameters for Photodynamic Therapy on Periodontal Disease
Status:
Completed
Trial end date:
2017-06-26
Target enrollment:
Participant gender:
Summary
Due to the phenomenon of bacterial resistance, photodynamic therapy (PDT) has been studied as
an alternative to the use of antibiotics on the periodontal treatment. However, the studies
show several discrepancies between the parameters adopted for PDT, which makes it difficult
to compare the results and measure their efficacy. The objective of this research was to
investigate the tissue dosimetric parameters used in PDT for the treatment of periodontal
disease. In order to achieve this objective, the scattering pattern of light in periodontal
tissue, the concentration of methylene blue in the periodontal pockets and the number of
viable microorganisms were evaluated. This clinical trial included 30 patients with chronic
periodontitis according to the eligibility criteria. The patients were in periodontal
treatment at the Dental Clinic at the University of Nove de Julho, where the research was
carried out. Three incisors from each patient were selected for the experimental procedures.
The pattern of light scattering was observed through intraoral photographs. A laser with
emission of radiation with wavelength of 660 nm and 100 mW of power was used. The
concentration of the photosensitizer (PS) in the periodontal pockets was evaluated by
spectrometer before irradiation. Methylene blue was used as PS at the concentration of 100 μM
in two different formulation and vehicles to evaluate the drug dimerization. Then, the
procedures of irradiation of the PDT were carried out, with 3 irradiation times of 1, 3 and 5
min. The microbiological evaluation was performed from subgengival biofilms of the
periodontal pockets of the experimental sites, before and immediately after the irradiation
procedures.