الفهرس | Only 14 pages are availabe for public view |
Abstract The present study aimed to compare the efficiency of single file system (Neoniti) versus multifile system (Protaper Universal) in reducing Enterococcus Faecalis biofilm in the root canals using different methods of activation of irrigation (conventional syringe, passive ultrasonic irrigation and vibringe). Fifty – four human extracted mandibular permanent first and second molars were selected. The mesial root of each molar was separated at the bifurcation. Root canals selected were type III. 48 roots were divided into 2 equal groups (n=24) and they were equally distributed in length. Root canals were enlarged to ISO # 20. Smear layer was removed. They were packed in two separate sterilization pouches and steam autoclaved at 121 ° C for 30 minutes. A clinical isolate of E. faecalis from the Microbiology laboratory was used for biofilm formation. Monitoring of bacterial biofilm development onto root canal dentin was assessed by SEM examination after three weeks using the positive control group (n=3). 3 samples were served as the negative control group to check for the sterility of the procedures and 3 samples were served as the positive control group to check for bacterial viability throughout the experiment & used as indicators for biofilm formation. Pre-instrumentation bacterial sampling (S1) was taken from the two experimental groups and the negative control group by placing # 15 K-file into the canal to within 1 mm of working length and circumferentially filed for 10 seconds then a sterile absorbent paper point size 15 was placed in the root canals, adsorb the transport fluid (Saline) and transferred into a test tube containing 1.0 ml of 0.9% sterile saline. Each sample was diluted then 0.1 ml from each dilution was smeared to be inoculated on surface of the plate media (BHI agar plates), incubated at 37°C for 48 hours, and colony-forming units (CFU) per 1 ml were enumerated. Root canal instrumentation was done according to the manufacturer instructions for the 2 experimental groups: group I: (n=24) (Protaper universal) till F2 (25/0.08). group II: (n=24) (Neoniti) single file (25/0.08). Patency by K-file # 10 and irrigation by saline (total amount for the 2 root canals = 10 ml) by 28 gauge needle were made between each file and the next. Post instrumentation bacteriologic sampling (S2) was taken by paper point size 30. Each group will be further subdivided into 3 subgroups (n = 8 ) according to the method of activation of irrigation : a) Subgroup A: By conventional plastic syringe. b) Subgroup B: By Passive Ultrasonic Irrigation. c) Subgroup C: By vibringe. Post activation bacteriologic sampling (S3) was taken by paper point size 30. |