antimicrobial effect of different concentrations of simvastatin and triple antibiotic paste on enterococcus faecalis biofilm at different stages of development in dental canal

Abstract

Enterococcus faecalis is one of the most resistant species in the canal and is resistant to most canal disinfection processes and is one of the causes of root canal failure. It is also more resistant in biofilm mode than planktonic. The aim of this study was to evaluate and compare the antibacterial activity of TAP and simvastatin at concentrations of 1 and 10 on 4 and 6 weeks of Enterococcus faecalis biofilms. Methods: In this study, 70 single root and single canal teeth without anomalies and decay were used. After cleaning and preparing the canals, a solution containing Enterococcus faecalis was placed inside the canal of the teeth and new culture medium was added everyday to form biofilm of bacteria. In the first group, this procedure was performed for 4 weeks and in the second group for 6 weeks. Then, 5 samples from each group were examined for confirmation of biofilm formation under scanning electron microscope. Subsequently, each group was divided into 5 subgroups and the antimicrobial agent was administered as an intracanal medicament. In the first subgroup, TAP with a concentration of 1 mg / mL and the second subgroup of TAP with a concentration of 10 mg / mL and the third and fourth subgroups simvastatin with concentrations of 1 and 10 mg / mL and the fifth subgroup phosphate buffered saline (control) was used for one week. The results of the study were reported using descriptive statistics (mean ± standard deviation). Kruskal-Wallis test was used to compare the CFU level in three groups of TAP, simvastatin and phosphorous-buffered saline (PBS) separately at 4 and 6 weeks, due to unusual distribution of data. The comparison between CFU at 4 and 6 weeks in each group based on the abnormal distribution of data was performed by U-Mann-Whitney test. Statistical analysis was performed using SPSS 17 software. The significance level was considered as P <0.05. Results: The mean CFU observed in the 4-week subgroup in the simvastatin and TAP groups at 1 mg / ml were 814.29 ± 561.99 and 320 ± 207.36 and at 6 weeks was 348.57 ± 197.27 and 58.33 ± 91.09, respectively. There was no significant difference between the two times with concentration of 1 mg / ml in the simvastatin and TAP groups. Also, the mean CFU observed in the 4-week subgroup in the simvastatin and TAP groups at 10 mg / ml were 98.57 ± 99.07 and 20 ±20, and at 6 weeks was 247.29 ± 313.79 and 91/91 ± 33/58 respectively. There was a significant difference (P = 0.038) in the simvastatin group at a concentration of 10 mg / ml between 4 and 6 weeks. Conclusion: According to the results of the present study, the antibacterial activity of simvastatin and TAP in the concentration of 10 mg / ml against both 4 and 6-week-old Enterococcus faecalis biofilms was higher than their concentration of 1 mg / ml. The effect of these substances at a concentration of 10 mg / ml against biofilm for 4 weeks was more than 6 weeks.