Photodynamic Treatment of Endodontic Polymicrobial Infection In Vitro

Abstract

We investigated the photodynamic effects of methylene blue (MB) on multi-species root canal biofilms comprising Actinomyces israelii, Fusobacterium nucleatum subspecies nucleatum, Porphyromonas gingivalis and Prevotella intermedia in experimentally infected root canals of extracted human teeth in vitro. The four test microorganisms were detected in root canals using DNA probes. Scanning electron microscopy (SEM) showed the presence of biofilms in root canals prior to therapy. Root canal systems were incubated with MB (25 µg/ml) for 10 minutes followed by exposure to red light at 665 nm with an energy fluence of 30 J/cm 2 . Light was delivered from a diode laser via a 250 µm diameter polymethyl methacrylate optical fiber that uniformly distributed light at 360°. Photodynamic therapy (PDT) achieved up to 80% reduction of colony-forming unit counts. We conclude that PDT can be an effective adjunct to standard endodontic antimicrobial treatment when the PDT parameters are optimized.

Evaluation of the dentin changes in teeth subjected to endodontic treatment and photodynamic therapy

“…Conventional endodontic therapy combined with PDT has shown to be capable of reducing the presence of resistant and biofilm-forming microorganisms within the RCS, as demonstrated by in vitro, in vivo, and ex vivo studies [11][12][13] . However, the literature has scarce information regarding morphological changes induced to the dentin structure by PDT.…”

Comparison of the Antibacterial Effect of 810 nm Diode Laser and Photodynamic Therapy in Reducing the Microbial Flora of Root Canal in Endodontic Retreatment in Patients With Periradicular Lesions

“…14 Several studies have shown that oral bacteria are sensitive to photodynamic therapy (PDT). 15,16 In recent years, in vitro [17][18][19][20][21][22][23][24][25][26] and in vivo [27][28][29] studies have been performed to investigate the antibacterial effect of the PDT on the microorganisms in root canal. Most of these studies have focused on the PDT capability as a complementary technique besides the conventional endodontic treatment.…”

Assessment of Photodynamic Therapy (PDT) in Disinfection of Deeper Dentinal Tubules in a Root Canal System: An In Vitro Study

“…Photo Dynamic Therapy was actually developed as a therapy for cancer and is based on the concept that a nontoxic photosensitizing agent, known as a photosensitizer, which can be preferentially localized in premalignant and malignant tissues and subsequently activated by light of the appropriate wavelength to generate singlet oxygen and free radicals that are cytotoxic to cells of the target tissue [14]. Several studies have shown that oral bacterias are susceptible to PDT.…”

“…MB predominantly interacts with the anionic macromolecule lipopolysaccharide, resulting in the generation of MB dimmers, which participate in the photosensitization process [14].…”

“…Jacob Lee Fimple et al, [14] Garcez AS et al, used PDT along with conventional endodontic treatment in vivo and concluded that PDT leads to major reduction of microbial count. PDT is an efficient treatment to kill micro organisms having multi-drug resistant [18].…”