Aim: The role of various host response mediators in pulpitis has been extensively documented as these components may operate as biomarkers that reflect the condition of pulp tissues. The expression of these biomarkers is further affected in the presence of different systemic diseases. This review aims to assess if a correlation exists in the expression of cytokines and endodontic infection in patients having various systemic diseases undergoing nonsurgical endodontic therapy. Materials and Methods: The review includes a complete manual search as well as electronic databases such as PubMed, Scopus, and EBSCOhost. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist was used to frame the review process. The critical appraisal checklist for quasi experimental studies developed by Joanna Briggs Institute was used to examine the risk of bias. For prospective clinical studies, eight criteria were used to assess the risk of bias. The studies included were clinical trials that estimated mRNA expression of cytokines from periapical interstitial fluid before and following disinfection of the root canals in patients suffering from various systemic diseases. Results: This review included a total of four papers from the initial 122 publications. When compared to normal controls, endodontic infection was associated with altered expression of these cytokines in patients presenting various systemic diseases. Conclusions: This information can subsequently be utilized to correctly distinguish between diseased and healthy pulp tissues. The interaction of cytokines in systemic diseases and their possible use in endodontics as a more precise and biologically based diagnostic tool can be planned.

Aim: To comparatively evaluate in vitro the cyclic fatigue resistance of different file systems based on different manufacturing technologies after exposure to NaOCl and multiple sterilization cycles. Materials and Methods: Sixty new Nickel − Titanium (NiTi) rotary files were selected and divided into five groups (n = 12) based on different manufacturing technology. These groups were: Protaper Universal (G_PT) (DentsplyMaillefer, Ballaigues, Switzerland) Protaper Next (G_PTN) (Dentsply, Tulsa, OK, USA), Twisted files (G_TF) (Sybron Endo, Orange, CA, USA), Neoniti (G_NL) (Neolix, France), and Hyflex CM (G_HCM) (Coltene/whaledent inc., 235 Ascort Parkway, Cuyahoga falls, OH, USA). Files were sterilized in an autoclave at 121°C at 15 psi for 15 min and exposed to 5.0% NaOCl solution for 30 s before cyclic fatigue testing till instrument fracture using a standardized grooved block assembly with the artificial canal at 90° angle of curvature using a 16:1 reduction hand-piece powered by a torque-controlled motor. This whole procedure of autoclaving, immersion in sodium hypochlorite solution and rotating in a stainless steel assembly was repeated again and again until the file fractured. Results: The highest mean for the number of cycles before fracture was observed with Neoniti (G_NL) and lowest for Hyflex CM (G_HCM). The difference between G_PT vs G_TF, G_PTvs G_NL, G_NLvs G_HCM; G_PTNvs G_TF, G_PTNvs G_NL, G_PTNvs G_HCM; G_TFvs G_NL, G_TFvs G_HCM and G_NL VS G_HCM was statistically significant, whereas the difference between G_PTvs G_PTN was statistically nonsignificant. Conclusion: Neoniti and twisted file systems resisted the maximum number of cycles to fracture at 90° angle of curvature after exposure to 5% sodium hypochlorite solution and multiple autoclaving cycles. Hyflex CM showed the least resistance in the similar conditions.

Aim: The present in vitro study was designed to determine the effect of different access cavity designs on intracoronal bleaching of endodontically treated teeth with two different agents. Materials and Methods: Fifty selected permanent maxillary central incisors were stained. Traditional and contracted access cavity designs and two types of bleaching agents, i.e., 35% carbamide peroxide and 35 percent hydrogen peroxide were used for the study. Color measurements were performed with a spectrophotometer: before staining (T1), after staining (T2), at 7 and 14 days (T3 and T4) post bleaching. The values were calculated and subjected to the statistical analysis. Results: The results of our study showed that teeth in which traditional access cavity (TAC) was prepared had statistically significant better bleaching results with both 35% carbamide peroxide and 35% hydrogen peroxide than contracted access cavity design. Carbamide peroxide showed better results than hydrogen peroxide irrespective of the access cavity design, but difference was statistically nonsignificant. Conclusion: The present study concluded that TAC design showed better results than contracted access with both carbamide peroxide and hydrogen peroxide. Whereas, when bleaching agents were compared 35% carbamide peroxide is better than 35% hydrogen peroxide irrespective of access cavity design used.

Aim: The aim of this study is to compare the antibacterial efficacy of cerium oxide nanoparticles and calcium hydroxide as intracanal medicaments against Enterococcus faecalis on tooth substrate – an in vitro study. Materials and Methods: The experiment was conducted in three stages. In Stage 1, antibacterial susceptibility test of three test materials, cerium oxide nanoparticles, calcium hydroxide, and vancomycin against E. faecalis was done using disc diffusion method. In Stage 2, determination of minimal inhibitory concentration and minimum bactericidal concentration of the cerium oxide nanoparticles was done by tube dilution method. In Stage 3, determination of CFU was carried out using dentinal blocks at 1-day and 5-day intervals at two different dentinal depths (200 μm and 400 μm) for calcium hydroxide (Group 1), cerium oxide nanoparticle dispersion (Group 2), a mixture of calcium hydroxide and cerium oxide nanoparticles (Group 3), and sterile water (Group 4). Results: The reduction of E. faecalis achieved by cerium oxide nanoparticles dispersion on day 5 was 66.9% as against 46.7% as shown by mixture of the two medicaments and 34.8% by calcium hydroxide paste alone on day 5 at 400-μm depth. Conclusion: Cerium oxide nanoparticles show a significantly higher antibacterial efficacy when compared to calcium hydroxide and its combination.

Introduction: Glide path preparation permits predictable debridement and shaping of radicular space while reducing procedural errors like apical extrusion of debris and microorganisms which can postpone healing. The aim of this study was to comparatively evaluate the effect of glide path files with different metallurgy on apically extruded Enterococcus faecalis. Materials and Methods: Forty human mandibular bicuspids were selected, decoronated, and autoclaved. The samples were placed in a test apparatus of sterilized glass vials and inoculated with E. faecalis. The specimens were randomly allocated into four major groups (n = 10) each depending on the glide path file used – Group I with Proglider, Group II with EdgeGlidePath Files, Group III with Neoniti GPS, and Group IV without rotary glide path instruments using HyFlex electrical discharge machining (EDM). After glide path preparation, final canal preparation was done with HyFlex EDM. The apically extruded E. faecalis was counted as colony-forming unit and was converted into log values. Statistical analysis was evaluated using Kruskal–Wallis H Test and Mann–Whitney U-test using SPSS software; version 22.0 (SPSS INC., Chicago, IL, USA). Results: Group IV without glide path preparation technique showed maximum extrusion of E. faecalis in comparison to other groups (P < 0.05). Groups I and II showed a similar quantity of extruded bacteria. Group III showed significantly higher bacterial extrusion than Groups I and II. Conclusions: Glide path preparation groups showed less amount of apically extruded E. faecalis. EDGEGlidePath files showed lesser apically extruded E. faecalis in comparison to Proglider and Neoniti GPS.

Aims: The aim is to evaluate the retreatability of BioRoot RCS (BCS)/Gutta-percha (GP) as compared to AH Plus/GP with and without a solvent using cone-beam computed tomography (CBCT). Materials and Methods: Mesio-buccal canals in 48 first mandibular molars were instrumented using iRace rotary files up to size 25.4% and obturated with GP using one of the following sealers, BCS and AH Plus. Post obturation, the teeth were scanned using a CBCT. All samples were divided into four groups (n = 12). Group 1: GP/BCS was removed using D-Race retreatment files and xylene as a solvent; Group 2: GP/BCS was removed using D-Race retreatment files without xylene; Group 3: GP/AH Plus was removed using D-Race retreatment files with xylene; Group 4: GP/AH Plus was removed using D-Race retreatment files without xylene. Time taken to reach the working length (WL) was recorded. Samples were again scanned using CBCT and the remaining filling material was calculated in the coronal, middle, and apical thirds. Data were tabulated and analyzed via Kruskal–Wallis and Mann–Whitney Post hoc test (P < 0.05). Results: Group 3 exhibited significantly less time to reach WL as compared to Group 1. There was no significant difference between Group 2 and Group 4. In all groups, the apical third had the most remaining filling material (Group 1 – 13.75 ± 4.83, Group 2 – 18.33 ± 3.26, Group 3 – 10.42 ± 3.34, Group 4 – 15.42 ± 3.34). WL and patency were re-established in all the samples. Conclusions: Irrespective of the retreatment technique employed complete removal of both the sealers could not be achieved. However, retreatability of AH Plus with xylene was superior to that of BioRoot RCS.

Aim: Using N acetyl cysteine (NAC) and Chlorhexidine as final irrigants, the study aims to examine the push out bond strength of distinct sealers. Materials and Methods: Access and biomechanical preparation were done on decoronated 80 single-rooted teeth. Canals were alternatively irrigated using 5ml of 5.25% NaOCl and 5ml of 17% EDTA solution during instrumentation. On the basis of final irrigation procedure, the samples are divided into two groups: Group 1 – NAC and Group 2 – 2% Chlorhexidine. Using paper points, canals were dried and subdivided depending on the sealers used, Group 1A and 2A- AH plus and 1B and 2B- BioRoot RCS. Teeth were obturated and middle root sections were tested for push-out bond strength using universal testing equipment. Statistical analysis was done. Results: NAC with AH-plus sealer had the maximum push-out strength, whereas Chlorhexidine with BioRoot RCS sealer had the lowest. Conclusion: NAC increases the bond strength of the obturating materials as the final irrigant. NAC can be considered as a final irrigant for endodontic therapy.

Aim: This study intended to compare the effectiveness of manual files H-files and ProTaper universal retreatment (PTUR), R-Endo retreatment, and gutta-percha removal (GPR) Mani retreatment rotary files for removing root canal filling material. Materials and Methods: Eighty mandibular premolars with single canal were selected. The canals were enlarged with ProTaper rotary files up to F2 and obturated using the lateral condensation technique. Then, the samples were randomly divided into four groups and retreated using hand files and rotary retreatment files. The area of remaining root canal filling material was evaluated by splitting the tooth using a stereomicroscope with ×10 and auto computer-aided design software and the percentage of remaining filling material on canal walls was calculated with equation: area % of remaining filling material = area of remaining material ×100/area of canal. One-way ANOVA was carried out to compare the groups and post hoc Tukey's test for pairwise association with each of four groups. Results: Group A (H-files) showed 61.87% of remaining filling material, Group B (PTUR) showed 24.94%, Group C (R-Endo) showed 37.12%, and Group D (GPR Mani) showed 45.95% of remaining root canal filling material. Conclusions: All the groups showed residual root canal filling material. Least was seen in group retreated using PTUR files and maximum was seen in group retreated with H-files.

Aim: This split-mouth (SM), randomized controlled trial was planned to assess the influence of two different volumes (15 ml and 25 ml) of 2.5% of sodium hypochlorite (NaOCl) on the endodontic treatment outcome of teeth with apical periodontitis (AP) by radiographic and clinical evaluation. Materials and Methods: The study protocol was approved by the ethics committee (25/XX/IEC/2017/11). Using block randomization, permanent lower molars with pulp necrosis and chronic AP (periapical index [PAI] of 3 or above) were allotted to two treatment groups as Group I (low volume [LV]) and Group II (high volume (HV)) wherein 3 ml and 5 ml of NaOCl irrigant were used after each Mtwo rotary file, respectively. This NaOCl was activated by a sonic handpiece. With power at 0.80, P < 0.05, and minimum clinically significant mean intergroup difference set at 0.40 units (standard deviation – 0.88 unit) while using the change in PAI score as the primary outcome, a total of 46 subjects per group were recruited to adequately show a difference in success at the 12-month follow-up. Clinical (at 24 h, 3, 6, 9, and 12 months) and radiographic (6 and 12 months) assessment of all cases was done. Results: Due to SM design of the study, there was no difference in the demographics of subjects between both the groups. Pain scores between both groups were statistically nonsignificant preoperatively (P = 0.857) and at 24 h (P = 0.852). However, there was statistically significant difference in preoperative and 24 h pain scores in Group I (P = 0.000) and Group II (0.000). Comparison of intergroup preoperative and 12-month follow-up PAI scores revealed no statistically significant difference (P = 0.667). However, there was statistically significant difference in preoperative and 12-month follow-up PAI scores in Group I (P = 0.000) and Group II (P = 0.000). Intergroup comparison of PAI scores at baseline (P = 0.894) and follow-up (P = 0.526) revealed no significant difference. Conclusion: Based on the results of the present study, it can be suggested that there is no significant advantage of using HV of NaOCl over LV as far as periapical healing and postendodontic pain are concerned.

Aims: We aimed to investigate the effect of instrument length on the torsional resistance and bending property of three nickel–titanium files, namely ProTaper Gold (PTG), ProTaper Next (PTN), and HyFlex CM (HCM) using finite element analysis. Materials and Methods: Three-dimensional models of each aforementioned system were created using the computer-assisted design (CAD) software SolidWorks^® 2016 (Dassault Systèmes, SolidWorks Corp., Concord, MA, U. S.). Then, all models were imported to the ANSYS^® Workbench 16 (Canonsburg, PA, U. S.) where the simulation was computed. The boundary conditions used to simulate the behavior of the endodontic instruments were in compliance with the ISO 3630 1 specification standards. Results: It was observed that in bending test, HCM model exhibited load of 510.35 MPa with displacement of 6.05 mm, followed by PTG model (465.48 MPa) and 11.21 mm displacement, then PTN file model (440.74 MPa) and 10.30 mm displacement, whereas in torsional test the rigidity curve for HCM file (1.9673 N mm/Radian) lies much below PTG (6.4615 N mm/Radian) which clearly shows that HCM is flexible as compared to PTG and PTN. Conclusion: Considering the high flexibility of the HCM file, it can be effectively used in severely curved root canals and PTG and PTN files in moderately curved root canals. It was also recommended that HCM files should not be kept in canals for a longer time because stresses might reach to ultimate level quickly which can cause fracture.

Aim: This study aimed to evaluate the influence of humidity on the bond strength of AH Plus, BioRoot RCS, and Nanoseal-S sealers. Materials and Methods: Sixty root slices, each 1 ± 0.1 mm thick, were prepared from the middle-third of 20 mandibular premolars. Three holes, 0.8 mm wide each, were drilled on each slice. These holes were subjected to standardized irrigations and dried. Each hole in each slice was filled with the three individual sealers, AH Plus, BioRoot RCS, and Nanoseal-S. The samples were then stored in saline for 7 days at 37°C. The push-out bond strength of each sealer in each hole of all samples was tested. The differences in push-out bond strengths between the three sealer samples were assessed using the unpaired t-test and post hoc Turkey's HSD test. The significance level was set at 5%. Results: The results of the post hoc Tukey's HSD test (P < 0.05) indicated that the mean and median push-out bond strength were highest for BioRoot RCS, irrespective of the moisture conditions. Conclusion: Humidity conditions did not influence the bond strength of AH Plus, BioRoot RCS, and Nanoseal-S sealers.

Internal inflammatory root resorption is an uncommon pathology that can progress to the periradicular vicinity. It is frequently asymptomatic and only discovered during a radiological screening. Appropriate and timely diagnosis is extremely crucial in tackling these cases. A perforating internal resorptive cavity in the distal root of the mandibular first molar was successfully managed using a sandwich concept of sectional apical obturation with gutta-percha and Bioceramic sealer followed by the placement of mineral trioxide aggregate in the resorptive cavity.

Understanding root canal anatomy and its variations is an essential part of the success of endodontic treatment. This case report represents an extremely rare occurrence of four distal root canals in a two-rooted mandibular first molar (MFM). Nonsurgical endodontic treatment of MFM was performed with the aid of the dental operating microscope and ultrasonic troughing tips. PubMed database (www.ncbi.nim.nih.gov/pubmed) was searched for relevant articles using specific search terminologies for conducting the literature review. Data extraction was performed in relation with the inclusion and exclusion criteria provided in the study. Quantitative data synthesis was performed. Only four cases (including the present case) of four distal root canals in two-rooted MFMs have been reported in dental literature. Among these, three cases were reported in the Indian population. The overall incidence of four canals in a distal root of two-rooted MFMs is 0.09% according to clinical/laboratory studies. The most common distal root canal configurations of two-rooted MFMs found in clinical/laboratory studies were Vertucci type I (68.15%) followed by type II (37.6%) and type III (35.08%). A meticulous understanding of the anatomical variations, preoperative awareness, and intraoperative care to identify the landmarks of usual as well as any unusual anatomy of the root canal system will help to increase the rate of clinical success.