(PR16) Assessment of Antibacterial Effect and Flowability of a Modified BC Sealer with Chitosan Nano-Particles

Introduction: The primary reason for endodontic treatment failure is microbial infection inside the root canal system by different microbes including E. faecalis. Endodontic sealers with Chitosan (CS), a compound with antimicrobial effects, can decrease the growth of microorganisms and potentially prevent failure. The purpose of this study was to assess the antimicrobial activity and flowability of calcium silicate root canal sealers with added CS fillers. Materials and methods: EndoSequence (BC) sealer was mixed with CS fillers in two different concentrations (5% and 10%wt). Flowability was analyzed according to ISO-6876. To assess the antimicrobial activity extracted single-rooted teeth were infected with E. faecalis for seven days. Follow the root canal treatment the sealers (BC, BC+CS-5%, BC+CS-10%, N=6) were used for obturation and re-incubated in the bioreactor for 24 hours. Untreated teeth were used as positive control. Cell viability (CFU/mL) and fluorescence microscopy were used to determine the number of bacteria at the bonded interface. ANOVA was used for statistical analysis.

Results: Addition of CS fillers into BC resulted in a significant decrease in flowability (BC:22mm, BC+CS-5%:19mm, BC+CS-10%:16mm). All evaluated sealers showed antibacterial activity. The addition of CS significantly reduced the CFUs (CS-5%:5.3, CS-10%:4.6) compared with the BC (5.9) and positive control (7.2). Fluorescence analysis showed that CS-Sealers group had an increased number of dead cells (CS-10%:77.3%, CS-5%:64.4%) compared with the BC-Sealer (37.9%) and positive control (23.3%).

Conclusion: Endodontic sealers with added CS enhanced antimicrobial effects of the sealer. However, adding more than 5% of CS affects the flow properties of the sealer.