engleski

The antimicrobial effectiveness of photodynamic therapy used as an adjunct to conventional endodontic retreatment: a clinical study

Objective: The aim of this study was to evaluate the efficacy of photodynamic therapy (PDT) used as an adjunct to endodontic retreatment in the eradication of microorganisms. Background data: PDT is an antimicrobial strategy in which low laser energy is used to activate a photosensitizer, and the singlet oxygen released causes damage to the microorganisms. Methods: The study sample consisted of 21 patients with chronic periapical periodontitis on single rooted teeth, who have had previously endodontic treatment. Microbiological samples from the root canals were collected after accessing the canal, following endodontic retreatment and after the PDT procedure. Twenty one teeth were retreated, instrumented with ProTaper files, and irrigated with 2, 5% sodium hypochlorite and 17% ethylenediaminetetraacetic acid. Root canals were filled with phenothiazine chloride, which was removed after 2 min. Irradiation was performed with a 3D Endoprobe of a diode laser (λ=660 nm, 100 mW) for 1 min. Microbiological samples from the root canals were cultivated on selective plates, and identification was done by micromorphology, macromorphology and different API strips. Results: Fourteen bacteria species were isolated from root canals initially, with a mean value of 4.57 species per canal. Although endodontic retreatment alone produced a significant reduction in the number of bacteria species (p<0, 001), the combination of endodontic treatment and PDT was statistically more effective (p<0, 001), and suceeded in the total elimination of bacteria from 11 root canals. Conclusion: The results indicate that the PDT used as an adjunct to the conventional endodontic therapy achieves a significant futher reduction of intracanal microbial load.

laser; dentistry; endodontics; aPDT; microbiology

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