جستجوی مقالات مرتبط با کلیدواژه "انتروکوکوس فیکالیس" در نشریات گروه "پزشکی"

Conventional processes of drinking water disinfection could not completely remove contamination indicator bacteria. So, application of new technologies like ultrasonic process has been considered for drinking water disinfection. In this study, the performance of the ultrasonic process on removal of E. coli and E. faecalis from drinking water was evaluated. In this cross-sectional study, synthetic solution contained E. coli and E. faecalis with populations of 103, 105, 107 and 109 cfu/mL (Colony Forming Unit/ milliliter) were used. After microbial seeding, drinking water samples were exposed to ultrasonic waves with the cycle of 2, 6 and 10 Pulse/s in 5 and 10 minutes. A measurement criterion of the disinfection performance was removal efficiency of indicator bacteria. Microbial colonies were counted by McFarland and plate count methods. The ultrasonic power and microbial concentration in the process of inactivation of bacteria were compared by using McFarland method. In this study, the removal performance of E. coli with colony density of 103 cfu/mL and the sonication cycle of 2 pulse/s was 1.1 log, while in the sonication cycles of 6 and 10 pulse/s was 3 log (p<0.009). Also, the removal performance of E. faecalis with colony density of 103 cfu/mL, the sonication cycle of 2 pulse/s and retention time of 5 min was 0.52 log which had significant difference in compared to the sonication cycles of 6 and 10 pulse/s which was 3 log (p<0.001). The removal efficiency of all bacterial populations was 3 log, in retention time of 10 min. By increasing the initial population of the bacteria, the performance of the disinfection process was significantly decreased (p<0.001). The result of this study showed that the ultrasonic process was effective in removal of E. coli and E. faecalis from drinking water and its efficiency was independent from bacterial population.

The use of calcium hydroxide powder in saline as an intracanal drug is common. Recently, the use of chlorhexidine solution for irrigation due to its antibacterial property has increased significantly. The Purpose of this study was to compare the antimicrobial activity of calcium hydroxide combined with chlorhexidine gluconate against E-Feacalis and to compare the results with the calcium hydroxide mixed with saline and by chlorhexidine alone.In this study, 40 teeth with single canal were used. After removing the crown and preparation of the canal with step-back technique, the root canal was irrigated with EDTA solution to remove smear layer. Then, all the samples were sterilized in autoclave and the roots were infected with E faecalis and incubated. Subsequently, the roots were divided into 3 treatment groups. Group 1 was treated with calcium powder hydroxide in salin, group 2 with calcium hydroxide powder in chlorhexidine, and group 3 with chlorhexidine. All the samples were incubated for a period of one week at 37˚C. Sampling was done by paper point. The microbiological samples were plated to count the colony-forming units and the level of CFU was assessed at the wavelength of 540nm by photometer. The mean number of colonies in all the three groups was assessed by variance analysis, and turbidity and transparency of the samples were assessed via chi-squares (x2) test.The results showed that chlorhexidine gel was significantly more effective than calcium hydroxide with chlorhexidine, calcium hydroxide, and control saline solution (p = 0.06).The results revealed that chlorhexidine gel has antibacterial effects against E-Feacalis. In fact, the study in the field showed that adding chlorhexidine to calcium hydroxide results in an increase in antibacterial effect of calcium hydroxide and reduces the antimicrobial effect of chlorhexidine.

Statement of Problem: The main goal of endodontic treatment is eradication of microorganisms and their byproducts from the root canal system. The use of chemical irrigants during chemo-mechanical canal preparation is important for disinfection and cleaning of the canal system. The aim of this in vitro study was the assessment of bacterial growth after contact with several concentrations of essential oil of Zataria multiflora in varying time intervals. The essential oil of Zataria multiflora were serially diluted 8 folds and a fixed volume of the stationary phase culture of E.faecalis was added to each diluted solution, for varying intervals of 1, 5 and 15 minutes. 100µl of the contents of each tube were transferred to SF broth and incubated for 48h at 370c. Results of bacterial growth were recorded at the end of the incubation period. 2% solution of essential oil of Zataria multiflora at all intervals inhibits growth of E.feacalis. 1% solution of it showed antibacterial effect in 5, and 15 minutes. The concentrations under 0.5% dilution of Zataria multiflora did not eliminate E.faecalis at any time intervals. It seems that 1% and 2% solutions of essential oil of Zataria multiflora were effective at destroying E.faecalis. Application of this plant essential oil may be recommended for root canal irrigant following extensive ex-vivo and in-vivo experiments.

Statement of Problem: Bacteria and their destructive byproducts are the main causes of pulpal and periapical diseases. The main goal of the root canal therapy is to eliminate these bacteria from the root canal systems to prepare a suitable environment for the healing of periradicular tissues. Total elimination of these bacteria from root canal system is impossible, even by cleaning, shaping and irrigating with antibacterial solutions; therefore, utilization of antibacterial filling materials can help to achieve a better result. The purpose of this study was an in vitro comparison of antibacterial effect of AH26 and AHplus sealers on infected root canals with enterococcus faecalis bacteria. For this experimental study, 90 single rooted human teeth including upper incisors and canine were chosen. The crowns were removed and the root canals were cleaned and shaped. Smear layer was removed from canals and the roots were contaminated with entrococcuous faecalis bacteria following their sterilization. The roots were randomly divided into four experimental groups. The root canals of two groups were obturated using gutta percha and AH26 sealer with the lateral condensation technique. Root canals of the remaining groups were obturated by the same method but by using AHplus sealer. After incubation periods of 2 and 7 days, 4 mm segments were prepared from the middle third of roots and following removal of gutta percha from the segments, dentinal shavings were collected from the inside walls of the segments. The dentinal shavings were cultured and the presence of bacteria and the number of colonies were evaluated. The data were compared with each other by Mann-Withney and Chi-Square tests. The findings of this study demonstrated that AH26 sealer can kill all the bacteria in 2 and 7 days but AHplus sealer can not eliminate the bacteria from the infected root canals and a significant rise in the number of colonies was seen when comparing the incubation period of 2 days with 7 days. The findings of this survey illustrated a strong antibacterial effect of AH26 in comparing with AHplus which may be due to the greater amount of formaldehyde releases from this sealer.