Antibacterial Effect of Two Types of Nano Particles Incorporated in Zinc Oxide Based Sealers on Enterococcus Faecalis (in Vitro Study)

INTRODUCTION: Antibacterial properties of nanoparticles have recently come into the spotlight in endodontic therapy. OBJECTIVES: Evaluation of the antimicrobial efficacy of zinc oxide based sealer incorporated with silver and zinc oxide nanoparticles compared with simple zinc oxide sealer against Enterococcus faecalis. MATERIALS AND METHODS: The study was conducted on 60 human extracted mandibular premolars. After instrumentation of all teeth and inoculation of root canals with Enterococcus faecalis, teeth were divided into three groups according to the type of the tested sealer, Group I: control group where teeth were obturated with unmodified zinc oxide based sealer. Group II: teeth were obturated using sealer modified with silver nanoparticles, Group III: teeth were obturated using sealer modified with zinc oxide nanoparticles. Each group was subdivided into two subgroups according to the timing of filling removal and culture sample. Subgroup A: filling removal and culture sample were taken after one week. Subgroup B: filling removal and culture sample were taken after three weeks. Colony counting technique was used , the number of colony forming unites method was counted to assess the effect against Enterococcus faecalis. Data were recorded, tabulated and statistically analyzed using Friedman test to compare the differences between the three groups. RESULTS: After three weeks from obturation, silver nanoparticles had a superior antibacterial effect and there was a significant difference between the three tested groups, but after one week of obturation there was no significant difference between the three tested groups. CONCLUSION: In three weeks samples after obturation silver nanoparticles had a superior antibacterial effect and there was a significant difference between the three tested groups, but after one week of obturation there was no significant difference between the three tested groups.