The effect of the combination of cetrimide and photodynamic therapy in reducing Enterococcus faecalis load from the root canal system

Aim: To evaluate the effect of cetrimide (CT) in combination with photodynamic therapy (PDT) on the reduction of Enterococcus faecalis in the root canal system.

Methodology: Forty mesiobuccal canals from extracted human mandibular molars contaminated with the standard strain of Enterococcus faecalis were selected. Instrumentation was performed using the WaveOne Gold Primary file (25.07) and specimens were randomly divided into two groups (n=20): PDT - 0.01% methylene blue photosensitizer was applied for 5 minutes, PDT was performed with 660 nm, 9 J red laser for 90 seconds with fiber optics; CT + PDT - Cetrimude was placed for 60 seconds, photosensitizer was applied, and PDT was performed as described in the PDT group. Samples were collected before instrumentation and after disinfection procedures for each group. The results were subjected to the Kruskal-Wallis statistical test (Student-Newman-Keuls) with a significance level of 5%.

Results: There was a microbial reduction before and after PDT and CT +PDT (p<0.0001). The use of CT in conjunction with PDT resulted in a significant increase in microbial reduction compared to the use of PDT alone (p=0.0226). There was no significant difference between sample groups in microbial counts performed prior to disinfection protocols (p=0.5448).

Conclusion: The use of CT in conjunction with PDT proved to be highly effective in allowing deeper penetration of the photosensitizer into the dentinal tubules, thus improving the root canal disinfection process.