mahdieh nourzadeh

The main cause of endodontic failure is residual bacteria in the root canal system. Enterococcus faecalis (E. faecalis) is the predominant species isolated from infected root canals. This study aims to compare the antibacterial activity of calcium-enriched mixture (CEM) cement and Biodentine as root canal filling materials on E. faecalis. Methods and Materials: Seventy extracted human single-rooted teeth were prepared and infected with E. faecalis for 24 h. Specimens were randomly divided into control or experimental groups; the later were filled with either CEM cement or Biodentine. Dentinal samples were collected after 7 and 30 days and transferred to test tubes. After incubation, the number of colony forming units (CFUs) were counted and analyzed using the Kruskal-Wallis test, followed by the Mann Whitney U test. The level of significance was set at 0.05. The reduction in mean CFU level of E. faecalis was significantly more in the presence of CEM cement at both time intervals (P<0.001). Compared to the positive control, Biodentine significantly reduced the mean CFU level only after 30 days (P<0.01). Although both biomaterials exerted antibacterial activity against E. faecalis, the CEM cement had more antibacterial activity than Biodentine.

Learning and memory requires a brain-derived neurotrophic factor (BDNF)-dependent phase in the hippocampus. It has been reported that chronic pain decreases hippocampal BDNF levels. We have also previously reported that noxious stimulation of the rat tooth pulp impairs learning and memory. Therefore, we decided to find the changes in the hippocampal BDNF expression which are associated with tooth pain and learning and memory impairment. Dental pulp nociception was induced by intradental injection of capsaicin (100μg) in male Wistar rats. BDNF expression levels were determined by semi-quantitative RT-PCR and western blotting. The data indicated that capsaicin elicited pain behaviors and impaired learning and memory in Morris water maze test. The protein and mRNA levels of BDNF were significantly (P<0.05) decreased in capsaicin-treated rats as compared with control animals. Furthermore, iboprofen (120mg/kg, ip) treatment caused a significant (P<0.05) up-regulation of the BDNF protein and mRNA in the hippocampus of capsaicin-injected animals. These findings suggest that inflammatory dental pain induces hippocampal function impairments by decreasing in BDNF expression.

The aim of this study was to evaluate the antimicrobial effect of Eucalyptus galbie and Myrtus communis L. methanolic extracts, chlorhexidine (CHX) and sodium hypochlorite (NaOCl) on Enterococcus faecalis (E. faecalis) as the predominant species isolated from infected root canals.
Methods and Materials: One hundred twenty mandibular premolars were randomly divided into 8 groups: Eucalyptus galbie (E. galbie) 12.5 mg/mL, Myrtus communis L. (M. communis L.) 6.25 mg/mL, 0.2% CHX, %2 CHX, 2.5% NaOCl, 5.25% NaOCl, positive and negative control group. Sampling was performed using paper points (from the root canal space lumen) and Gates-Glidden drills (from the dentinal tubules); then colony forming units (CFU) were counted and analyzed using the Kruskal-Wallis test, followed by Mann Whitney U test. The level of significance was set at 0.05.
All irrigants reduced more than 99% of bacteria in root canal. In the presence of M. communis L. and E. galbie, the bacterial count in dentin were significantly more than CHX and NaOCl groups (P0.05).
Although 5.25% NaOCl was the most effective irrigant, all agents exerted acceptable antimicrobial activity against E. faecalis.

Human dental pulp inflammation can progress to periapical lesion formation and conventional root canal treatment (RCT) has been the traditional method for disease management. This observational study presents two cases of vital pulp therapy in mature molars diagnosed with irreversible pulpitis and associated with apical periodontitis. In these two clinical cases, the involved teeth had deep carious lesions with a history of spontaneous/lingering pain and radiographic examinations revealed the presence of apical radiolucencies. A conservative miniature pulpotomy (MP) using calcium-enriched mixture (CEM) was performed and the teeth were permanently restored with amalgam. Clinical evaluations indicated resolution of pain 24 hours after treatment; the teeth showed normal vitality, remained asymptomatic and maintained normal function after recall examinations. Furthermore, the 18-month radiographic evaluation showed healing of the apical lesions. Vital pulp therapy using the MP technique with CEM appeared successful in avoiding RCT intervention. These two reports of case outcome suggest that simple MP using a CEM bioregenerative technique may provide a favorable outcome for permanent teeth diagnosed with irreversible pulpitis and associated with apical periodontitis.

The aim of the present study was to evaluate the effect of different needle-insertion depths on the accuracy of the Root ZX II and Root ZX mini apex locators in the presence of various irrigants. Ninety extracted single-canal human teeth were used in nine experimental groups. The coronal one-third of the canals was preflared, and the length to the major foramen was determined visually under a microscope. The teeth were embedded in an alginate model. NaOCl concentrations of 5.25%, 2.60%, and 2.00% chlorhexidine with three endodontic needles (21, 25, and 30 gauges) were delivered into the root canals of teeth in each group. Electronic length was determined with both devices using K-files of size 10. The results obtained with electronic apex locators were compared with the corresponding actual length. A multivariate linear regression model was used to determine the variables influencing the accuracy of the Root ZX II and Root ZX mini apex locators. Irrigant solution concentrations had no effect on the accuracy of the measurements with these locators (P = 0.83). The statistical analysis of the results showed EAL accuracy to be 100% for both Root ZX and Root ZX mini, within a tolerance of ± 0.5 mm. Data were analyzed by ANOVA. Multivariate linear regression model demonstrated that needle-insertion depths influenced the electronic measurements (P = 0.05), while the concentrations of irrigants did not influence the results. Under the conditions of this ex vivo study, needle-insertion depths influenced the electronic measurements.