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Background: Electrochemical disinfection of the root canal system (RCS) is introduced as an alternative to conventional irrigation. The aim of this study was to assess the efficacy of depotphoresis method in the disinfection of accessible and inaccessible RCSs., Materials and Methods: In this comparative in vitro study disinfection of Enterococcus faecalis -infected RCS using two methods, (1) depotphoresis and (2) sodium hypochlorite (NaOCl) irrigation plus passive ultrasonic agitation (PUA) took place on 40 extracted maxillary anterior teeth. Decoronation was done with a diamond disc, and the canals were instrumented. The roots were divided into two phases: the specimens with canal obstruction and the specimens without canal obstruction. The smear layer was removed, and the specimens were infected for 21 days with E. faecalis . After disinfection procedures, bacterial samples were taken using two sterile #35 paper points, and colony-forming units (CFU) were counted. Data were analyzed statistically using the Kruskal-Wallis test, with a significance level at P < 0.05, to indicate differences between depotphoresis and NaOCl plus PUA groups., Results: In both phases, Log CFU after depotphoresis treatment was significantly lower than NaOCl irrigation plus PUA treatment ( P < 0.05)., Conclusion: Treatment with depotphoresis was significantly more effective than NaOCl irrigation plus PUA treatment., Competing Interests: The authors of this manuscript declare that they have no conflicts of interest, real or perceived, financial or non-financial in this article., (Copyright: © 2023 Dental Research Journal.)

Background: Mineral trioxide aggregate (MTA) becomes a hard mass after setting and making it difficult to remove and can cause significant problems in the retreatment process. The aim of this study was to evaluate the effect of different concentrations of hydrochloric acid (HCl) on MTA dissolution and its effect on dentin., Materials and Methods: In this in vitro study, 45 single-root premolars were selected. Artificially open apex was created in all samples with similar process. The samples were randomly divided into 4 experimental groups of 10, and a control group of 5. Four-millimeter thick apical plugs of Root MTA were placed in all samples in an orthograde manner. HCl was used at concentrations of 3.75%, 7.5%, 15%, and 22.5% (w/v) for the experimental groups and normal saline for the control group. Each sample was exposed to the desired solution for 15 min. Then, MTA retrieval and reaching the working length were attempted with k-file # 30. The times of each sample were recorded. Furthermore, after longitudinal incision of the roots with a disc, the dentin surfaces of canals were examined with a Dino-Lite microscope (×50). Results were analyzed by Shapiro-Wilk test and one-way analysis of variance tests. The level of significance P value was set at 0.05., Results: The lowest average time of reaching working length was observed with group 22.5% that was significantly lower than 15% and 7.5% concentrations ( P = 0.005 and P = 0.011). Furthermore, by examining with ×50 of Dino-Lite microscope, no difference was observed on the canal walls., Conclusion: The optimum concentration of HCl was 7.5%. Furthermore, different concentrations of HCl had no significantly different effect on the dentinal canal wall using Dino-Lite microscope with ×50., Competing Interests: The authors of this manuscript declare that they have no conflicts of interest, real or perceived, financial or nonfinancial in this article., (Copyright: © 2023 Dental Research Journal.)

Background: Apical leakage assessment is a way to compare the efficiency of a filling material to seal the apical region of the tooth. Many microleakage testing techniques have been introduced through the years, but there has been no agreement as to which technique gives the most accurate results. The aim of this study was to compare the accuracy of fluid filtration and bacterial leakage techniques in the assessment of the apical sealing ability of mineral trioxide aggregate (MTA) and calcium enriched mixture (CEM)., Materials and Methods: A sample of 34 extracted single-rooted human teeth were selected and prepared. The samples were divided in to 2 experimental groups. The apical 3 mm of each root was resected at 90° to its long axis and root end preparation was done with ultrasonic tips to a depth of 3 mm and filled with MTA and CEM, respectively. Assessment of apical sealing ability was done with fluid filtration technique and bacterial leakage technique along 90 days with Enterococcus faecalis bacteria. Mann-Whitney U-test and Chi-square test were used to analyze the data using SPSS (SPSS Inc., Chicago, IL, USA). P less than 0.05 was considered as significant., Results: There was no significant difference in apical sealing ability between MTA and CEM in bacterial leakage and fluid filtration techniques. Samples which had bacterial leakage showed higher leakage values by fluid filtration technique., Conclusion: Both techniques showed same results and there was no significant difference between fluid filtration and bacterial leakage techniques in assessment of apical microleakage.

Background: The aim of the present study was to investigate the quality of root canal obturation performed by 6(th) year undergraduate dental students at the Dental School, University of Mashhad, Iran., Materials and Methods: A random 200 sample records of patients who received endodontic treatment at the Dental School, University of Mashhad between 2009 and 2010 was investigated. The quality of root canal filling was determined in relation to the adequate density and length of root filling. Statistical analysis of the data was carried out using statistical package for the social sciences (SPSS 12.0, SPSS Inc., Chicago, IL, USA) with Chi-square test. P < 0.05 was considered as significant., Results: About 38% of teeth fulfilled the criteria of an acceptable root canal filling. Adequate length and density of root filling was found in 73% and 66% of teeth respectively. There was significant difference between maxillary and mandibular teeth according to the quality (P = 0.009), length (P = 0.039) and density (P = 0.005) of root filling. The frequency of root canals with an acceptable filling was significantly greater in the anterior teeth than in molars., Conclusion: The technical quality of root canal treatment performed by undergraduate dental students was found to be less than ideal. Thus, the training course of the students at the preclinic and clinic has to be revised.