[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

[Affect of three antibacterial mouthwashes chlorhexidine 0.2%, povidine iodine 1% and cetyl pyridinum chloride 2.5% on bacterials strep cultures]

Dental plaque is the main cause of periodontal disease. Prevention and treatment of periodontal disease is provided by inhibition of plaque formation or its removal. Uses of Mouthwashes are one of the methods for plaque control. The purpose of this study was to determine the most efficient mouthwash in prevention of plaque formation. This experimental study consisted of 48 microbial culture. Antibacterial effect of three well known mouthwash: povidine iodine 1%, chlorhexidine 0.2% and cetyl pyridinum chloride 2.5% were studied on two bacterial species: strep mutans and bacterial melaninogenicus, which were obtained from dental plaque of three different patients. This mentioned bacteriac were added to culture mediums until the turbidity equivalent of number 0.5 macfarland tube was achieved Then mouthwashes were added to the cultures which were then placed in 37°C incubator in two different conditions, aerobic and anaerobic. The turbidity of the aerobic and anaerobic cultures were compared with standard Macfarland tubes after 24 and 72 hours respectively. Data analysis was done with ANOVA, kroscal valis and T-test. The mean number of streptococus mutans in one milliliter of the culture medium, with mouthwashes including povidine iodine 1%, chlorhexidine 0.2% and cetylpyridinum chloride 0.5% added was determined. 19.5x10[8], 0.19x10[8] and 0. 75x10[8] respectively and for bacteroid melaninogenicus: 12.75 x10[8], 0, 0.56 x10[8] was achieved respectively. Total average of bacterial number in one milliliter of culture, when mouthwashes were added was determined: 16.1 x10[8], 0.09 x10[8] and 0.65 x10[8] respectively. Result of this study showed that for each type of species and also in general, antibacterial effect of three applied mouthwashes in descending order was: chlorhexidine 0.2%, celypyridmum chloride 2.5% and povidine iodine 1%. In other word chlorhexidine can be suggested as elective mouthwash. Finally longitudinal study, invivo-invitro, with application of more mouthwashes and bacterial species is suggested