Aim: To evaluate the antibacterial efficacy of diclofenac potassium as intracanal medicament versus triple antibiotic paste against Enterococcus faecalis biofilm developed in single root canals by bacterial count assessment.



Methodology: Forty-two human-extracted mandibular premolars with single canals were instrumented up to #25 k-file then sterilized in an autoclave before inoculation with E. faecalis and then incubated for 14 days at 37°C. The 1st sample (S1) was taken after 14 days. The root canals were prepared up to #40 (MG3 Gold), then the 2nd sample (S2) was taken. The specimens were divided into 3 groups (n=14), the 1st group: (triple antibiotic paste), 2nd group; (diclofenac potassium paste), and the 3rd group (no medicament was applied). All specimens were sealed and left in an incubator for 7 days then the 3rd sample (S3) was taken after medicament removal. Bacterial count assessment was done by visually counting bacterial colonies on agar plates in which the measurement unit was (CFU/ml).



Results: There was a statistically significant difference between (TAP), (DP) and (NC) groups where (p<0.001). Regarding S3 samples, a statistically significant difference was found between (NC) group and each of (TAP and DP) groups where (p<0.001) while no statistically significant difference was found between (TAP) and (DP) where (p=0.098).



Conclusions: Diclofenac potassium has shown a significant reduction in E. faecalis count which is comparable to triple antibiotic paste.