Objective: The objective of this systematic review was to comprehensively assess the literature regarding the applications, accuracy, advantages and limitations of dynamic navigation in endodontics.
Methods: Case reports and laboratory studies in the English language, which used the Dynamic Navigation System (DNS) for endodontic application and assessed the accuracy of treatment, the time required for treatment and iatrogenic errors were included. PubMed, Scopus, Embase and Web of Science were searched for eligible articles (up to July 2021). Additional hand searching of four peer-reviewed endodontic journals and a grey literature search were also carried out. A risk of bias assessment was done using the Joanna Briggs Institute (JBI) critical appraisal checklists. Data were extracted based on endodontic application of DNS, tooth type, DNS brand, accuracy, iatrogenic errors, and time taken, followed by qualitative analysis.
Results: Fourteen articles (three case reports and eleven in-vitro studies) met the eligibility criteria and were included. The quality assessment revealed a low risk of bias, with mean scores of 83.34% for case reports and 84.09% for in-vitro studies. DNS was used for various clinical applications such as access cavity preparation, pulp canal obliteration, endodontic retreatment and microsurgery. The DNS brands used were Navident, X-guide, ImplaNav, and DENACAM. Due to the nature of the component studies, meta-analysis was not possible.
Conclusion: Challenging clinical situations like pulp canal obliteration, conservative access preparation, endodontic retreatment and microsurgery can be managed efficiently with fewer iatrogenic errors in a shorter time using DNS. However, this systematic review’s evidence is low since the included articles are either case reports or in-vitro studies. Clinical studies are needed to test DNS efficacy among operators, including those who are less proficient and compare the accuracy of currently available systems. (EEJ-2021-12-190)

The ‘glide path’ in non-surgical root canal treatment refers to a smooth radicular tunnel from the root canal orifice to its terminus. Its establishment is aimed at creating sufficient space to facilitate the subsequent and safer use of engine-driven nickel titanium (NiTi) shaping files. Glide paths were originally prepared using stainless steel hand files to, at least, a loose International Organisation for Standardisation (ISO) size 10 or larger. However, the advent of engine-driven NiTi instrumentation has led to the availability of many engine-driven NiTi glide path files. The aims of this review were to assess the effects of engine-driven and manual glide path preparation (GPP) on root canal shaping procedures and outcomes. An online search of the PubMed, Embase, Scopus and ScienceDirect databases was conducted and 32 studies were identified. The published literature suggests the use of engine-driven glide path files to be beneficial in maintaining the original root canal anatomy, reducing preparation time, decreasing apical extrusion of debris and causing less postoperative pain. However, there was no difference between engine-driven and manual GPP with regards to the physical strain exerted on the shaping files. Future research focused on clinical outcomes is needed to help ascertain the clinical benefits for patients. (EEJ-2021-03-057)

Objective: Adequate pain management is an essential key to success in endodontics. The present study aimed to evaluate the postoperative pain levels and analgesic intake on preemptive versus preventive oral administration of ibuprofen in single visit root canal treatment.
Methods: A total of 100 participants presented with symptomatic irreversible pulpitis and with severe baseline pain scores were selected for the study. The participants were randomly allocated into two groups as follows: Group I: preemptive group (n=50), Group II: preventive group (n=50). Participants in group I were administered preoperatively with 600 mg of ibuprofen tablet 1 hour before the procedure, whereas in group II, participants were administered only with a placebo preoperatively. The treatment was finished in a single visit, and 200 mg ibuprofen tablet was administered every eight hours in both groups. The participants were asked to take tablets only when required and evaluated for pain scores and analgesic intake at 6, 24, 48, 72 hour intervals.
Results: There was a statistically significant decrease (P<0.05) in both the pain levels and tablet intake in the preemptive group compared to the preventive group at 6, 24, 48 and 72 hours. Preemptive group was beneficial in reducing postoperative pain scores and analgesic intake at all time intervals.
Conclusion: Preemptive analgesic administration seems beneficial in reducing postoperative pain levels and analgesic intake in single visit root canal treatment. (EEJ-2021-04-070)

Objective: This study evaluated the effectiveness of Platelet Rich Plasma (PRP), Platelet Rich Fibrin (PRF) and Mineral Trioxide Aggregate (MTA) as direct pulp capping materials in patients with carious pulp exposure using cone beam computed tomography.
Methods: This parallel, triple blinded, randomised trial was done on 30 permanent posterior teeth chosen as candidates for direct pulp capping based on stringent inclusion and exclusion criteria. The samples were allocated based on sequentially numbered opaque sealed envelope method into three groups: MTA, PRP and PRF for direct pulp capping. The treated teeth were restored with Glass Ionomer cement liner and light-cured resin composite. Patients were followed up for a period of 12 months. Statistical analyses were performed with statistical software SPSS version 25. Data were analysed for normality using Shapiro Wilk’s test. Dentine bridge volume analysis across the groups were done using Kruskal Wallis test with the significance level at P=0.05. As the test revealed a significant difference, post hoc analysis was done with Dunn test.
Results: CBCT analysis revealed that the volume of dentine bridge formed by PRP and PRF was significantly higher than the volume of dentine bridge formed by MTA (P<0.001; CI: 90%). There was no significant difference in the efficacy between the three direct pulp capping agents based on clinical assessment. A total of 27 teeth (90%) showed positive response to pulp sensibility testing and evidence of dentine bridge formation in radiograph at 12 months. No adverse events were encountered.
Conclusion: Platelet concentrates could be the future of vital pulp therapy for adult permanent teeth with reversible pulpitis. (EEJ-2021-05-078)

Objective: This study was undertaken to compare microhardness and erosion susceptibility of root dentine in teeth extracted from diabetic and non-diabetic donors after the application of different root canal irrigants.
Methods: Forty-eight single-rooted premolars with single canals (24 each from diabetic and non-diabetic) were selected, and root canals were shaped by using rotary ProTaper files. Dentine slices of 4 mm were transversely sectioned from the middle root third. Specimens were assigned to four subgroups (n=6) and irrigated for 5 minutes: 1) 2.6% sodium hypochlorite (NaOCl); 2) 17% ethylenediaminetetraacetic acid (EDTA); 3) 2% chlorhexidine (CHX); and 4) normal saline. Surface microhardness was determined at 100- and 500-µm depths from the pulp–dentine interface. Scanning electron microscope (SEM) was used to determine the severity of dentine erosion. Data were analyzed by using two-way ANOVA, Post-hoc Tukey’s, and Chi-square tests (P<0.05).
Results: Diabetes as well as NaOCl and EDTA decreased surface microhardness of dentine significantly (P<0.05). Diabetes had little effect on the erosion susceptibility of dentine (P>0.05).
Conclusion: Root canal irrigants can significantly lower the microhardness; specifically, in diabetic patients, and may be a factor affecting the longevity of root canal-treated teeth. (EEJ-2021-08-146)

Objective: This study aimed to assess the genotoxicity and cytotoxicity of Sealer Plus BC (SBC), AH Plus (AHP) and MTA Fillapex (MTF).
Methods: Human periodontal ligament dental stem cells (hPDLSCs) from third molars were isolated and cultured in a clonogenic medium. Cells were maintained in an incubator, and cell growth was monitored daily. hPDLSCs were characterised under flow cytometry and stem cell surface markers. The tested groups were a control group, SBC, AHP and MTF. Each sealer was prepared according to the manufacturer's instructions and placed in a clonogenic medium to produce a conditioned media. Conditioned media were then diluted to 10% to be placed in contact with culture cells in cell viability assay afterwards. The cells were harvested and plated into 96 wells culture plates. Genotoxicity was assessed by evaluation of micronucleus formation and cytotoxicity by MTT-based assay. All experiments were performed in triplicate. Data normality was verified by the Kolmogorov-Smirnov test. Statistical analysis for genotoxicity was performed with Kruskal-Wallis and Dunn's tests and two-way ANOVA for cytotoxicity, both with a significance level of 5%.
Results: Cells expressed typical levels of mesenchymal stem cell surface markers. No differences in the number of micronuclei were observed among all groups (P>0.05). In all periods analysed (24, 48, and 72 h), the sealers presented statistically different results for cell viability (P<0.05), with SBC presenting the lowest cytotoxicity, followed by the control group, MTF, and AHP.
Conclusion: All sealers presented low genotoxicity, and Sealer Plus BC presented the lowest cytotoxicity. (EEJ-2021-09-158)

Objective: To evaluate the financial impact of the COVID-19 pandemic on endodontic clinics in Egypt.
Methods: Two hundred Egyptian endodontists holding a minimum of a master's degree were invited to participate in an online survey in March 2021. Participants accessed the survey link shared on the social media group of the Egyptian Society of Endodontology. Participants read and signed an electronic informed consent before participating in this study. The questionnaire was designed exclusively by the authors. A draft was pilot tested on a sample of 15 endodontic masters' students at The British University in Egypt. Suggestions and comments to improve clarity, content, and validity were incorporated into the revised survey. The questionnaire was divided into five sections; the first section comprised of questions about the participants' demographic details. The second section targeted the current and future financial impact of COVID-19 on practices. The third section included information about the average patient flow and the introduction of teledentistry in clinical practice. The fourth section assessed the effect of COVID-19 on the staff in the dental clinics and the changes made in response to COVID-19. The last section estimated COVID-19 prevalence among endodontists and staff. Categorical data were presented as frequencies (n) and percentages (%) and were analysed using Fisher's exact test. Quantitative data were presented as mean and standard deviation values. P-values were adjusted for multiple comparisons utilising Bonferroni correction.
Results: A total of 141 endodontists participated in the survey. The negative financial impact of COVID-19 was reported by 84.39% of the participants. Seventy-eight endodontists (55.3%) suffered from the increased cost of endodontic materials. Of the endodontist respondents, 90.8% suffered from the increased cost of PPE, 82.3% did not charge their patients more, and only 14.4% planned to charge more. A decrease in the number of referred cases for endodontic treatment has been noticed by 58.9%. About 47.5% noticed increased patient phone calls replacing patient visits. Only 12.8% have dismissed staff because of financial problems.
Conclusion: COVID-19 has negatively affected most endodontists financially and significantly affected their practices' strategies. (EEJ-2021-08-148)

Objective: The aim of the study was to compare the cleaning efficiency of XP Finisher (FKG Dentaire, La Chaux-de-Fonds, Switzerland), XP Finisher R (FKG Dentaire), and passive ultrasonic irrigation after root canal retreatment.
Methods: A total of 75 single-rooted human teeth were decoronated, instrumented using HyFlex EDM rotary files (Coltène/Whaledent Inc., Altstätten, Switzerland), and filled with gutta-percha and the TotalFill HiFlow bioceramic sealer (FKG Dentaire) using the warm vertical compaction technique. Retreatment was performed with D-Race rotary files (FKG Dentaire). Samples were randomly divided into five groups according to the activation protocol used. Samples were sectioned longitudinally and prepared for the scanning electron microscope. The percentages of cleaned canal walls in each third of the canal were determined using the ImageJ software. The one-way ANOVA test was used to make comparisons among all of the tested groups, with a pairwise comparison made with the Bonferroni correction. The significance level was set at P≤0.05.
Results: Results showed that none of the activation techniques used resulted in complete canal cleanliness. However, XP Finisher R and XP Finisher had better cleaning ability compared with passive ultrasonic irrigation in all thirds of each root canal (P<0.001).
Conclusion: The cleaning efficiency of XP Finisher R and XP Finisher was superior to that of passive ultrasonic irrigation after the retreatment of the hydraulic calcium silicate sealer. (EEJ-2021-07-116)

Objective: This study aimed to determine the correlation between sealer penetration into dentinal tubules and interfacial adaptation to root canal walls using a hydraulic calcium silicate-based sealer, Endosequence Bioceramic Sealer (Brasseler USA, Savannah, GA, USA), and an epoxy resin-based sealer, AH Plus (Dentsply DeTrey, Konstanz, Germany).
Methods: Sixty-four maxillary central incisors were endodontically prepared with nickel-titanium rotary instruments and randomly assigned into two groups (n=32). Roots were filled with gutta-percha using a single-cone technique in conjunction with one of the two sealers, AHP or BCS. Sealers were mixed with Rhodamine B and analysed under a confocal laser scanning microscope. Transverse sections at 5 mm from root apex were obtained. The circumference of the root canal wall was first outlined and measured to determine the circumferential percentage of sealer penetration. The regions along the canal walls where the sealer had penetrated the dentinal tubules were delineated and measured. Then, the outlined distances were divided by the canal circumference. The width of each gap was measured and pooled for each specimen for comparison to determine the interfacial adaptation. The measurements were repeated twice to ensure reproducibility. Mann-Whitney tests were performed to compare continuous variables between AHP and BCS groups. The correlation between gap width and percentage of sealer penetration was investigated using the Spearman correlation coefficient.
Results: No significant difference was observed between groups regarding the percentage of sealer penetration (P>0.05) and the gap width (P>0.05). Also, there was no significant correlation between the two variables analysed for AHP (r=0.165; P>0.05) and BCS (r=-0.147; P>0.05) and in the overall sample (r=0.061; P>0.05).
Conclusion: The present results show no correlation between interfacial adaptation and sealer penetration in dentinal tubules in the total sample and among sealer subgroups. The ability of root canal sealers to penetrate dentinal tubules cannot be considered a sign of better interfacial adaptation. (EEJ-2021-11-177)

Objective: To compare the ability of 5% carbohydrate derived-fulvic acid (CHD-FA) with 17%ethylenediamine tetraaceticacid (EDTA) on smear layer removal when used as a final irrigant, and to assess their effect on root dentin microhardness.
Methods: A total of 56 single-rooted human mandibular premolars were decoronated to obtain standardized root length of 12 mm. Canal patency was established using 10 size K-file, working length was determined. Based on the irrigation regimen, samples were assigned into three groups; 17% EDTA, 5% CHD-FA and distilled water (control). The canals were instrumented with Protaper till F3 size. A standardized volume of 5 mL of each testing solution was used for 1 min. Roots were longitudinally split into two halves with one half of the samples for SEM analysis to evaluate the smear layer removal at coronal, middle, and apical thirds of root dentin. The other halves of the samples were subjected to Vickers microhardness testing. The data was statistically analyzed using Kruskal Wallis and Post Hoc test (P<0.05).
Results: 5% CHD-FA and 17% EDTA showed significant smear layer removal at all levels compared to distilled water (P<0.05). In the apical third, 5% CHD-FA showed significantly increased smear layer removal than EDTA (P<0.05). Microhardness testing of apical third showed significantly lesser reduction in microhardness for CHD-FA than EDTA (P<0.05).
Conclusion: 5% CHD-FA could be a promising final irrigant for smear layer removal with decreased microhardness reduction on root dentin compared to 17% EDTA. (EEJ-2021-09-155)

Objective: This in vitro study aimed to evaluate the fracture resistance of endodontically treated premolar teeth restored with flowable short fibre-reinforced resin composite (FSFRRC) at varying depths within the root canals.
Methods: Fifty freshly extracted human single-rooted premolars were divided into 5 Groups (n=10), Group I (IN) intact teeth, Group II (P) restored coronally with resin composite only, Group III, IV and V (FSFRRC2, FSFRRC4, FSFRRC6) based on post space preparation to the respective depths of 2, 4 and 6 mm. Root canal treatment was performed for all the samples of Group II, III, IV, V and the teeth were decoronated 2 mm above cementoenamel junction. Following decoronation, post space preparation was done to the depths of 2, 4, and 6 mm (Group III, IV, V). Teeth were restored with FSFRRC (Groups III-V) intra-radicularly and coronally sealed using resin composite. All the teeth were subjected to fracture strength test using Universal testing machine, and mode of failure was analysed. Kruskal-Wallis test followed by Dunn Post-hoc test was conducted for statistical analysis. Statistical significance was set at P<0.05.
Results: All FSFRRC groups showed higher fracture resistance than teeth restored only with resin composite. FSFRRC4 and FSFRRC6 showed significantly (P<0.05) higher fracture resistance than intact teeth and other experimental groups.
Conclusion: Intra-radicular placement of FSFRRC increased the fractured resistance significantly and may serve as a promising alternative to conventional post systems to rehabilitate endodontically treated teeth. (EEJ-2021-07-117)