Efficacy of root canal treatment in c-shaped canals with adjunctive photodynamic therapy using micro-CT

Aim: To investigate the efficacy of conventional root canal treatment (cRCT) with adjunctive photodynamic therapy (aPDT) against microbial biofilms within infected c-shaped root canals. Methods: In this in vitro report, the inoculation of 20 freshly extracted human mandibular molar teeth having c-shaped root canal configuration was performed with E. faecalis and P. aeruginosa to produce three-day biofilms in prepared canal system. PDT used a combination of chlorin (ce6) and polyethylenimine (PEI) as the photosensitizer (PS). A 200 μ-fiber was employed to deliver a 660 nm diode laser light into the root canal, and this was compared and conjugated with conventional endodontic treatment utilizing antiseptic irrigation and mechanical debridement. Results: The utilization of aPDT (group-2) resulted in a considerable decrease in the count of E. faecalis and P. aeruginosa from 12.84 ± 2.18 CFU/mL to 5.13 ± 0.67 CFU/mL, and from 14.06 ± 3.98 CFU/mL to 4.82 ± 1.05 CFU/mL pre-and post-treatment, respectively. A statistically significant reduction in the bacterial counts of both microbes was observed after treatment among the samples of the both study groups (p < 0.05). Specimens in group-2 (8.42 ± 1.14 MPa) demonstrated the highest mean push-out bond strength, whereas the lowest was shown by samples in group-1 (7.08 ± 1.09 MPa). ANOVA showed no statistical difference between the research groups (p = 0.676). The independent t-test revealed that the mean push-out bond strength scores of the cervical segments were higher than the apical and middle segments of roots in research groups (p < 0.05). Conclusion: In c-shaped root canals, the application of photodynamic therapy as an adjuvant to conventional root canal treatment contributes to a statistically significant decrease in the microbial count of E. faecalis and P. aeruginosa along with an improved push-out bond strength of the root canal filling material with root.