[Comparing the bacterial leakage in endodontic therapy following using EDTA as a irrigation and AH26 or tubliseal as selars]

Complete root canal seal is one of the most important aims of root canal treatment. For this purpose, elimination of the smear layer and the kind of sealer used have important roles. The aim of this study was to compare the sealing ability of two sealers [ZOE and resin based] against the microleakage of entrococcus faecalis when used in association with three different root canal irrigants [17% EDTA, 7% citric acid, 20% citric acid]. In this experimental study, 170 single - rooted extracted human teeth were selected. Step back canal preparation was performed to Iso size No. 40 in the apical portion of the canals with 5.25% Naocl irrigation. The teeth were randomly divided into 8 groups: six experimental groups of 25 teeth and two control groups of 10 teeth. Final irrigation in groups 1 and 2 was preformed with EDTA+NaClO; in groups 3 and 4 with 7% citric acid+NaClO; and in groups 5 and 6 with 20% citric acid+NaClO. Groups 1, 3 and 5 were obturated with guttapercha and AH[26] sealer, and groups 2, 4 and 6 with guttapercha and Tubliseal sealer using lateral condensation. The 10 positive control teeth were obturated with a single guttapercha cone and the 10 negative control teeth were thoroughly obturated with gutta-percha and sealer. After 48 hours in 100% humidity and 37°C temperature, the roots were assembled in the designed system for this experiment. A fresh solution of entrococus faecalis was injected to the system every 3 days. The samples were evaluated daily for 160 days and the time of culture contamination with E. faecalis was registerd in each case. ANOVA and Duncan tests were used to analyze the results. All the samples in positive control group were infected after 24 hours. None of the negative control samples were infected after 160 days. Group 1 [EDTA+AH[26]] and group 3 [7%citric acid+AH[26]] had no significant difference with group 2 [EDTA+Tubliseal] and group 5 [20% citric acid+AH[26]], but group 2 and 5 were significantly different [P<0.001]. Group 4 [7% citric acid+Tubliseal] was not significantly different from group 6 [20% citric acid+Tubliseal] but they both were significantly different from the other four groups [P<0.001]. In this study 20% citric acid used in association with AH[26] showed the greatest microleakage mean time. The least microleakage mean time occurred in the group for which 20% citric acid was used in association with Tubliseal

[Cytolethal distending toxin [CDT] produced by Campylobacter jejuni and Campylobacter coli isolated from chikens by tissue culture method in Isfahan]

Campylobacter jejuni is one of the most common bacterial cause of diarrheal disease in humans throughout the world. Contamination is mainly linked to the consumption of undercooked food products contaminated with Campylobacters. The most characterized toxin proposed is CDT, which has been detected in several Campylobacter species. With regard to the role of broiler chickens in transmission of campylobacter to human and the possible role of CDT in the pathogenesis of Campylobacter, detection of Campylobacter producing CDT is necessary. In this study 368 rectal swabs were collected from chikens. All the specimens were cultured on Skirrows and Blood agar and incubated in microaerophilic conditions at 42°C for 48-72 h. Hella cell was applied to detect CDT in C. jejuni and coil. Campylobacter strains were isolated from 114 [31%] of 368 chicken [101 C. jejuni and 13 C. coli]. Toxin production in C. jejuni and C. coil was 94% and 76.9% respectively. It seems that the majority of C. jejuni and C. coli produce CDT although C. jejuni produces a higher titer