Effect of photodynamic therapy in combination with various irrigation protocols on an endodontic multispecies biofilm ex vivo

Abstract

Aim To analyse the antibacterial effect of photodynamic therapy (PDT) in combination with various irrigation protocols on a multispecies biofilm in root canals ex vivo. Methodology A total of 160 extracted human single-rooted teeth were divided into four groups (n = 40). In group G1, root canals were instrumented up to size 60 (control group), whereas in G2 to G4 canals were enlarged up to size 40. All root canals were inoculated with a multispecies biofilm (Enterococcus faecalis, Streptococcus oralis, Prevotella intermedia) for 5 days. In G2 to G4, instrumentation up to size 60 was performed using 0.9% sodium chloride (NaCl) (G2), 1% sodium hypochlorite (NaOCl) (G3), 1% NaOCl and a final irrigation with 2% chlorhexidine (CHX) (G4), respectively. In all groups half of the specimens received adjunctive PDT using phenothiazine chloride as photosensitizer and a diode laser (wavelength 660 nm). Counts of colony-forming units (CFUs) in each group were analysed separately for planktonic and dentine-adherent bacteria immediately after therapy (T1) and after 5 days of further incubation (T2). Descriptive statistics and two-way analysis of variance were carried out to analyse reduction of planktonic bacteria and nonparametric tests were used to analyse dentine-adherent bacteria.Results CFU reduction in planktonic bacteria was significantly affected by the irrigation protocol at T1 and T2 (P < 0.0001), but PDT significantly reduced CFUs only at T2 (P = 0.01; ANOVA). Irrigation using NaOCl, CHX and adjunctive PDT significantly reduced CFUs at T2 (P < 0.0001; Tukey HSD) compared to the control group. In 85.6% of all samples the same categories of CFU counts in both planktonic and dentine-adherent bacteria were detected at T1 and T2. Conclusions Adjunctive photodynamic therapy in combination with an irrigation protocol including NaOCl and CHX was an effective method for reduction of bacterial biofilm inside the root canals of extracted teeth.

Disinfect Porphyromonas gingivalis Biofilm on Titanium Surface with Combined Application of Chlorhexidine and Antimicrobial Photodynamic Therapy

“…In this study, the combination of CHX and aPDT treatment was more effective than CHX or aPDT alone in reducing the number of P. gingivalis on both polished and SLA titanium surfaces. Few reports have been published regarding the concurrent application of CHX and aPDT in eradicating endodontic (44,45) or periodontal pathogens (42). Hoedke et al evaluated the antibacterial effects of aPDT with different irrigation solutions on a multispecies biofilm in root canals ex vivo.…”

Microbiota of periodontal pockets and root canals in induced experimental periodontal disease in dogs

“…Even considering the limitations of sampling biofilms by using endodontic files/paper points, this approach is a well‐established protocol because all floating species present in the main RC/PP are or were members of the endodontic/periodontal biofilm . For assessment of microbiota in PP and/or RC, the literature has reported several studies using sterile paper points for sample collection . In addition, VMGA III is frequently used as transport medium, which avoids bacterial loss from PP and RC samples until laboratorial procedures …”

“…Besides the importance of microorganisms for induction/perpetuation of pulpal and periodontal diseases, the time required for bacteria to reach the apical foramen and, consequently, the main RC, remains unclear. Severe periodontal disease was induced for 125 days.…”

“…reported several studies using sterile paper points for sample collection. 3,13,22 In addition, VMGA III is frequently used as transport medium, which avoids bacterial loss from PP and RC samples until laboratorial procedures. 3…”

Diode laser in dental practice

“…D. Hoedke и соавт. (2017) также отмечают, что дополнитель-ное использование диодного лазера значитель-но снижало количество КОЕ [48]. E.M. Decker и соавт.…”