Jornal de Lasers, Óptica e Fotônica

Microrganism Collected in Periodontal Pocket Inactivation through Photodynamic Therapy: Pilot Project of an In vitro Study

Abstract

Rafael Monteiro*

This pilot study evaluated in vitro whether photodynamic therapy and the application of methylene blue are effective methods for eliminating microorganisms collected in periodontal pockets deeper than 5mm and cultivated in a petri dish. The study design consisted in the division of control group (G1) and two test groups (G2 and G3). Material resulting from subgingival scraping was collected in a region were periodontal pocket range from 5 to 7 mm in 1 patient, and this material was used to make a smear in a previously prepared culture medium, using a flamed bacteriological loop, inside a laminar flow hood. The growth of the cultures was monitored in a 36? incubator during 72 hours and after that period, tests of application of methylene blue 0.005% were performed in G2 and methylene blue 0.005% associated with photodynamic therapy in G3. 48 hours after this intervention, the cell colonies were removed from the culture medium using a bacteriological loop and applied to a glass plate, to perform the Gram staining method. The results indicated that there was no visible reduction in the size of cell cultures in G2 in relation to the control (G1), but there was a visible reduction in G3 in relation to the other groups. Microscopic analysis of gram staining indicated a significant reduction in the count of gram positive and negative bacteria in G3, but the same did not occur in G2 compared to G1. This pilot study demonstrated that photodynamic therapy is effective in inactivating microorganisms cultivated in vitro and that methylene blue at 0.005% concentration do not have enough antimicrobial effect to represent visible change in electron microscopy at 10X magnification.