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

Abstract

IntroductionMicrobial infection plays an important role in persistent periapical lesions.1 Insufficient disinfection of root canals could lead to treatment failure and persistent periapical pathology. 2Conventional techniques of root canal treatments such as mechanical instrumentation and chemical debridement with antimicrobial irrigants, such as sodium hypochlorite (NaOCl), chlorhexidine and calcium hydroxide do not always suffice to predictably render root canals free of bacteria.3,4 Factors such as anatomical complexities, bacterial growth as biofilm, render complete disinfection of the root canal system almost impossible. 5Studies have revealed a success rate of 94% with a negative culture before obturation has decreased to 68%, with a positive culture.2 Resolution of periapical lesions is more achievable when there is negative culture before obturation. 6Cross sectional studies have reported 20%-60% of treatment failure and 52% of endodontic failure in Iranian population.7-10 Existence of intracanal microorganisms would lessen the treatment outcomes of endodontic re-treatment comparing to primary endodontic treatment. 2Based on the previous studies, bacterial microflora in teeth with failed endodontic treatment is different from the microflora of the primary endodontic infection. All culture and PCR based methods have shown that primary endodontic infection is a polymicrobial infection involving fully anaerobic microorganisms, 5,11 while the failure AbstractIntroduction: The aim of this study was to compare the antibacterial efficacy of diode laser 810nm and photodynamic therapy (PDT) in reducing bacterial microflora in endodontic retreatment of teeth with periradicular lesion. Methods: In this in vivo clinical trial, 20 patients who needed endodontic retreatment were selected. After conventional chemo mechanical preparation of root canals, microbiological samples were taken with sterile paper point (PP), held in thioglycollate broth, and then were transferred to the microbiological lab. In the first group, PDT with methylene blue (MB) and diode laser (810 nm, 0.2 W, 40 seconds) was performed and in the second group diode laser (810 nm, 1.2 W, 30 seconds) was irradiated. Then second samples were taken from all canals. Results: CFU/ml amounts showed statistically significant reduction in both groups (P < 0.001). CFU/ml amounts were compared between the two groups and there was no statistical difference. Conclusion: PDT and diode laser 810 nm irradiation are effective methods for root canal disinfection. PDT is a suitable alternative for diode laser 810 nm irradiation, because of lower thermal risk on root dentin.

Comparison of the Antimicrobial Efficacy of Calcium Hydroxide and Photodynamic Therapy Against Enterococcus faecalis and Candida albicans in Teeth With Periapical Lesions; An In Vivo Study

“…No statistically significant difference was found between the 2 groups in this regard. Our results were in accordance with those of previous studies by George et al, 39 Garcez et al, 19,21,40 Bonsor et al 20 and Asnaashari et al 11,12,41 regarding the efficacy of PDT using laser or LED as light source. Only one study conducted by Souza et al reported opposite results.…”

Physiotherapeutic Intervention with Biofotododynamic Therapy for the Reduction of Pseudomonas Aeruginosa

“…Asnaashari, et al [28]. Also showed results that agree with our study, since they verified that the methylene blue in the concentration 0,01% associated to the application of low-level laser in the wavelengths of 810nm generate a reduction in the bacterial proliferation in the intensity of 0.2J [29]. Thus, we believe that these results occurred because the wavelength of 830nm is capable of stimulating the production of reactive oxygen that is responsible for the destruction of bacterial cells, justifying the reduction of colonies in applications with low-laser intensity associated or not with methylene blue [30].…”

Learning from clinical phenotypes: Low‐dose biophotonics therapies in oral diseases

“…The investigators noted addition of PDT showed increased effectiveness vs conventional chemo-mechanical preparation in endodontic retreatments associated with apical periodontitis. In another study, the same group utilized methylene blue and diode laser 810 nm at two powers settings, 0.2 W and 1.2 W for 40 s. They also noted a statistically significant reduction in bacterial microflora (CFU/ml) in endodontic retreatment of teeth with periradicular lesions (Asnaashari, Godiny, Azari-Marhabi, Tabatabaei, & Barati, 2016). Interestingly, the investigators did not note any differences between the two laser settings used suggesting the lower dose may be optimal for clinical safety and efficacy.…”