This systematic review aimed to evaluate the cytotoxicity of intracanal medicaments used for root canal disinfection and assess their effect on the proliferation and differentiation potential of stem cells from apical papilla (SCAP). The PubMed/Medline, Cochrane, Scopus, EMBASE, CINAHL and Web of Science databases were searched. Studies evaluating the effect of intracanal medicament on human SCAP (in-vitro primary cell culture experiment) were included in this systematic review. The risk of bias analysis of included studies was carried out using the Toxicological data Reliability Assessment tool. The data was analysed for qualitative characteristics. A meta-analysis was not carried out considering the heterogeneity of selected studies in terms of cell culture experiments, methods of analysis and the interpretation of results. Four studies fulfilled the desired inclusion criteria. The different antibiotic pastes and their intracanal concentrations lead to reduction in the SCAP survival compared to calcium hydroxide medicament. The findings were insufficient to make a clear distinction between different antibiotic pastes regarding their cytotoxicity. Within the limitations of the present systematic review, it can be concluded that calcium hydroxide is a relatively better intracanal medicament than antibiotic paste mixtures in terms of their cytotoxicity and effect on proliferation of SCAP. (EEJ-2021-03-044)

A systematic review and meta-analysis were conducted to evaluate the effectiveness of auxiliary methods in removing residual filling material (RFM). This systematic review has been registered with the International Prospective Register of Systematic Reviews (registration number CRD42020197482). A comprehensive literature search was conducted to identify relevant articles in electronic databases (PubMed, Embase, Cochrane) from January 2005 to March 2021. In vitro studies investigating or comparing at least one type of supplementary method or technique were included. A total of 26 studies were selected from the 239 records obtained after screening the databases. Ten of the included studies were suitable for meta-analysis. Strong evidence showed that ultrasonically activated irrigation (UAI) [SMD (95% CI): -0.52 (-0.88 to -0.16, P=0.266)] and XP-Endo Finisher R (XPR) [SMD (95% CI): -0.55 (-0.89 to -0.20, P=0.136)) contributed significantly to increase the removal procedure, and XPR has no significant superiority over UAI [SMD (95% CI): 0.36 (-0.12 to 0.84, P=0.994)]. Strong evidence was found to support the increased cleaning efficiency of the supplementary use of the Gentle Wave system, laser irradiation, XP Endo Finisher, and self-adjusting file. In contrast, conflicting evidence was found to support the use of sonic to improve the removal of RFM, and limited evidence was found to support the efficiency of Tornado Brush. Under in vitro conditions, UAI and XPR increase the removal of RFM from the root canal system during retreatment procedures. (EEJ-2021-08-143)

Objective: The objective of this study was to compare the effectiveness of premedication drugs including single dose Piroxicam and Prednisolone in regard to post endodontic pain at different time intervals (24, 48, 72 and 96 hours) after single visit root canal treatment.
Methods: This randomized clinical trial (registration no. NCT04124822) was performed in operative dentistry department of a private clinical institute. One hundred twenty patients identified with symptomatic irreversible pulpitis were included in the study. The pain intensity levels were marked through the use of visual analog scale (VAS) before the commencement of treatment. The participants were randomly allocated in three groups, Group I (n=40) received no medication (control), Group II (n=40) received Piroxicam (20 mg) and Group III (n=40) received Prednisolone (20 mg). The drugs were administered thirty minutes before the endodontic procedure was initiated. Root canal treatmentwas carried out followed by placement of provisional restoration in a single appointment. The patients were instructed to continue marking their pain intensity levels after 24, 48, 72 and 96 hours using VAS. All patients were called for follow up after 4 days for clinical evaluation and the placement of permanent restoration. The effectiveness of each drug over different time interval was studied employing ANOVA test. The significance level was set at P≤0.05.
Results: The results of the present study revealed that a higher percentage of patients in all 3 groups, reported no post-operative pain at all evaluated time durations (24, 48, 72, and 96 hours). However, the long term effectiveness (96 hours) of both drugs to reduce post-endodontic pain was observed to be statistically insignificant. There was no significant difference in demographic data in terms of age (P=0.14), gender (P=0.12), whilst tooth type (P≤0.05) showed statistically significant value.
Conclusion: Pre-medication with either single dose piroxicam or prednisolone was able to prevent post-endodontic pain in patients with symptomatic irreversible pulpitis. (EEJ-2021-07-129)

Objective: To evaluate the vertical forces induced with Reciproc (R) and Reciproc Blue (RB) systems during canal shaping.
Methods: Maxillary premolar teeth with two separate straight and constricted canals were chosen (n=26). After access cavity preparation, each tooth was fixed in a standing position on a stage connected to a force analyzing device (M5-20 Advanced Digital Force Gauge; Mark-10 Corporation, NY, USA). The glide path was prepared manually until K file sizes #15. Then, canals in all the groups were completely shaped with an R25/RB25 file (size 25,.08 taper). The canal shaping was done with a steady and gentle pressure on the file to give a slow “in-and-out” movement of 2 mm amplitude. The file was inserted three times until it reached the WL successfully. After each insertion, the canal was recapitulated and irrigated with a 1% sodium hypochlorite solution. The shaping time was analyzed by Student’s t-test. The inward and upward peak forces were used for analysis by using the Mann-Whitney test. All statistical analyses were performed using SPSS software at a 95% confidence level.
Results: Each root canal was shaped successfully with a single file inserted three times until the WL was reached. Within each group, the overall real-time force increased with the successive insertions of the file. The inward peak forces in both groups ranged from 1.71 to 8.38 N and the R group showed minimal peak forces than the RB group in the three insertions (P<0.05). The upward peak forces ranged from 1.50 to 3.26 N wherein both groups showed comparable peak forces at each insertion (P>0.05). The R and RB systems required average times of 22.01±3.08 and 23.93±4.15 s, respectively, to shape the canals completely (P>0.05). In this experiment, no file fracture took place during canal shaping.
Conclusion: The blue heat treatment influenced the forces developed during canal shaping. RB file was associated with higher inward peak forces than R file. (EEJ-2021-12-198)

Objective: This study evaluated the resistance to cyclic fatigue and the torsional strength of Prima One Gold® and WaveOne Gold® reciprocating systems.
Methods: Cyclic fatigue was tested in an artificial canal with 60º curvature, a 5 mm radius of curvature at 22°C (n=10) and 36.5°C (n=10). The torsional strength test followed ISO 3630-1, measuring torque and deflection angle until fracture (n=10). The t-test was used to compare the two groups, and the significance level was set at 5%.
Results: The Prima One Gold group presented greater resistance to cyclic fatigue at room temperature (P=0.001) and body temperature (P<0.001). For the torsional resistance test, the Prima One Gold group had a lower maximum torque value (P=0.029), despite having a greater deflection angle (P<0.001).
Conclusion: The Prima One Gold group showed greater resistance to cyclic fatigue regardless of temperature and a greater deflection angle. The WaveOne Gold group showed a greater maximum torque value than the Prima One Gold group. (EEJ-2021-05-087)

Objective: To compare, in vitro, the bioceramic materials (MTA and BC RRM-fast set putty) capacity to prevent microleakage of Enterococcus faecalis over time.
Methods: An experimental design was made with forty extracted human teeth, coronally cut, and prepared to be placed in a leakage system under sterile conditions. They were randomly divided into two experimental groups: thirty teeth (fifteen for each of retrograde filling material MTA and BC RRM-fast set putty) and a control group: ten teeth (five positive control, five negative control). The 3 mm root-ends were submerged in a brain-heart infusion broth with a red phenol indicator. The coronal access of each sample was inoculated with E. faecalis every seven days to maintain bacterial viability. The lower chamber was evaluated daily for 30 days to observe the turbidity of the culture medium and establish the presence and day of the filtration. Calculation of the colony-forming units (CFU) was performed for each leaked sample. Fisher's Exact Test was used to verify the association between the presence or absence of leakage of the samples by type of bioceramic material used and the Mann-Whitney U test to verify the existence of a difference between the average of CFU by type of bioceramic material used. The significance level used was α=0.05 and a 95% confidence level, as a decision rule for rejecting the null hypothesis.
Results: Of the total samples prepared for each group, leakage was found in 60.0% (9/15) of the MTA group and 40.0% (6/15) of the BC RRM-fast set putty group. All positive controls filtered on the first day of evaluation, while 20% (1/5) of the negative control leaked in the second week. There was no significant difference in leakege between the two groups, nor concerning the bacterial count (P=0.101) and the type of cement used (P=1.000).
Conclusion: BC RRM-fast set putty was comparable to MTA in resisting bacterial microleakage during the observation time. (EEJ-2022-02-028)

Objective: The present study was conducted to evaluate the presence of aerobic bacteria, anaerobic bacteria, E. faecalis, F. nucleatum, Propionibacteria sp., Actinomyces sp., and their reduction at various stages of endodontic retreatment with the use of conventional protocol (5.25 % Sodium Hypochlorite (NaOCl) as the irrigant along with Calcium Hydroxide (Ca (OH)2) as intracanal medicament and advocated protocol (SmearOFF as the irrigant along with 2% Chlorhexidine (CHX) gel as intracanal medicament).
Methods: Twenty eight patients fulfilling the eligibility criteria were selected for root canal retreatment and randomly allocated into two groups. Group 1: Final irrigant as SmearOFF+Chlorhexidine 2% gelas intracanal medicament (n=14). Group 2: Final irrigant as 5.25% NaOCl+Ca(OH)2 as intracanal medicament (n=14). With aseptic environment, access opening was performed followed by Gutta Percha (GP) removal and sample S1 was collected for bacterial analysis. The biomechanical preparation was done by using Reciproc system with additional finishing with XP-Endo Finisher R. Sample S2 was then collected for bacterial analysis after the final irrigation protocol in the respective groups. Intracanal medicaments were placed for one week and sample S3 was collected. All the samples were subjected to qualitative analysis using PCR and quantification was done by Colony Forming Unit (CFU) analysis.
Results: Aerobic [28/28], Anaerobic [28/28], Propionibacterium sp. [20/28] and F. nucleatum [24/28] were the most frequently isolated in S1 sample followed by Actinomyces sp. [16/28] and E. faecalis sp. [19/28]. Chemico-mechanical preparation followed by irrigation (S2 sample) resulted in significant reduction of all types of bacteria in both groups. Group-1 (SmearOFF as the final irrigant) had significantly superior efficacy against aerobic bacteria, E. faecalis and F. nucleatum (P<0.05) as compared to Group-2 (NaOCl). After medicament placement, significant differences between the groups were noted only for the E. Faecalis group. For the S3 samples, the mean bacterial reduction was significant in Aerobic and F. nucleatum in S3 samples for Group 1 and Group 2.
Conclusion: Chemico-mechanical preparation followed by irrigation resulted in significant reduction in bacterial load irrespective of the final irrigant. SmearOFF was significantly better than NaOCl in minimizing bacterial load of E. faecalis and F. nucleatum. 2% Chlorhexidine gel has superior antimicrobial efficacy against E. faecalis and may be recommended in secondary endodontic treatment. (EEJ-2022-01-05)

Objective: To evaluate the solubility, pH, antimicrobial action, and cytotoxicity of ambroxol hydrochloride (AMB), N-acetylcysteine (NAC), and calcium hydroxide (CH) pastes for use as intracanal medications.
Methods: Solubility was determined by micro-CT, based on the paste volume remaining after immersion in water for 7 days. pH was measured by immersing acrylic tubes containing the pastes in ultrapure water and then measuring pH after 3 hours, 3 days, and 7 days. Antimicrobial action against Enterococcus faecalis was assessed based on the percentage of living cells, using the live/dead staining method under confocal microscopy. Cytotoxicity was assessed based on the cell viability of L929 fibroblast-like cells after 6, 24, and 48 hours. Cytotoxicity data were compared using the ANOVA and Tukey tests, and the antimicrobial data were compared using the Kruskal-Wallis and Dunn tests. The significance level used was 5% (α=0.05).
Results: The solubility values for all the study groups were significantly different (P<0.05), where the highest values were for NAC, followed by AMB, and then CH. Likewise, the pH levels were all significantly different (P<0.05), where NAC and AMB levels were acidic, and CH levels were alkaline. The antimicrobial action of AMB was significantly higher than that of CH (P<0.05), and that of NAC was also higher than that of CH, albeit not significantly. AMB and NAC were more cytotoxic than CH, and higher dilutions of CH promoted higher cell viability levels than lower dilutions of the same paste (P<0.05).
Conclusion: : The NAC and AMB pastes were more soluble and cytotoxic than the CH paste and had acidic pH levels. The AMB paste displayed the highest antimicrobial action against Enterococcus faecalis biofilm. (EEJ-2021-12-209)

Objective: To explore the long-term effects on discolouration by demeclocycline HCl (Ledermix, LED) or doxycycline hyclate (Doxymix, DOX) pastes placed in extracted human teeth over a 27-month period under different storage conditions.
Methods: The canals in 38 teeth were prepared carefully, to minimize exposure to contamination from irrigants, then either LED (Lederle Pharmaceuticals, Germany) or DOX (Ozdent, Australia) were placed. Samples were stored in the dark for 3 months followed by daylight for 24 months. The storage conditions varied as follows: Group 1: Open access, dry storage (OD); Group 2: Closed access, dry storage (CD); Group 3: Open access, wet storage (OW); Group 4: Closed access, wet storage (n=4 for each material). Additional teeth were used as controls: Polyethylene glycol only in a closed canal; and saline only irrigation with LED paste in a closed canal. Standardised digital photographs were taken over 27 months and evaluated for changes in luminosity.
Results: Darkening of tooth structure occurred in all LED groups and in the two DOX groups that were stored wet, during exposure to light, with a faster rate with LED. The most rapid staining occurred with LED in moist conditions with an open access cavity. The least staining occurred with DOX in samples stored dry. With prolonged exposure to light, a reversal in staining occurred with DOX at 3 months and LED at 9 months.
Conclusion: Staining of tooth structure is influenced by the choice of medicament, and by exposure to moisture and air. Light has a bimodal effect, first driving staining, but later reversing it. This can be explained by different wavelengths of light causing photodegradation and photo-oxidation of tetracyclines and their complexes with tooth mineral. (EEJ-2022-03-039)

Objective: The aim of this study was to assess penetration of AH Plus, MTA Fillapex and GuttaFlow Bioseal sealers into dentinal tubules after placement and removal of silicone oil using Confocal Laser Scanning Microscopy.
Methods: Sixty single-canaled premolars were instrumented using ProTaper Universal rotary system. Roots were divided into two main groups (n=30) where either Silicone oil was used or not. Subsequently, each main group was subdivided into 3 subgroups according to the investigated sealers. In subgroups where Silicone oil was used, it was placed in canals and then cleared. Obturation was completed utilizing lateral compaction technique using Rhodamine B labeled sealers. Penetration depth of sealer was evaluated by image J software. One way ANOVA, Duncan's test as posthoc test was performed for evaluation of statistical significances among the groups. In each sealer group, Independent -t-test was used to compare between with and without oil. P value was set at <0.05.
Results: Using silicone oil resulted in less dentinal tubule penetration depth with all sealers. Mean dentinal tubule penetration depth was the lowest in apical thirds. AH Plus showed higher penetrability in all thirds compared to MTA Fillapex and GuttaFlow Bioseal despite oil placement and removal. MTA Fillapex displayed higher penetrability in all thirds than GuttaFlow Bioseal.
Conclusion: Remnants of silicone oil has a negative impact on the penetration depth of the tested sealers. (EEJ-2021-12-193)