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Objective: Published data obtained from in vitro and in vivo studies was reviewed systematically and analyzed critically in order to evaluate the effect of oral cavity derived stem cells (OCDSCs) on the recovery/therapy of neurodegenerative diseases (NDs) such as Alzheimer’s (AD), Amyotrophic Lateral Sclerosis (ALS), Huntington’s (HD) and Parkinson’s (PD). Methods: An electronic search was accomplished. References of included articles were also searched manually. Studies were critically evaluated for suitability against inclusion/exclusion criteria and data was extracted. Bias risk evaluation of the studies and evidence synthesis were conducted. Results: Fourteen in vivo and 10 in vitro studies met inclusion criteria. PD was induced in 10 in vivo and 7 in vitro studies, while AD was induced in 2 in vivo and 4 in vitro studies. Two studies (1 in vitro and 1 in vivo) evaluated ALS disease and 1 in vivo study evaluated HD. Moderate evidence was found for in vitro studies reporting positive effect of OCDSCs on either PD or AD recovery. Strong evidence was found for in vivo studies in which PD animal models were used; while moderate evidence was found for the impact of OCDSCs on the recovery of the AD. Limited evidence was found for in vivo studies evaluating HD and ALS. Conclusion: Although studies included reported favorable data regarding the OCDSCs on NDs, they presented considerable risk of bias. Because of heterogenous study characteristics, current study recommends the improvement of standardized methods to evaluate the therapeutics effects of OCDSCs on the NDs.

This review was designed to analyse whether the supplementary use of XP-Endo Finisher and XP-Endo Finisher R contributes to the removal of root canal filling materials. Databases were searched up to November 2020. Studies were critically assessed according to inclusion and exclusion criteria. Risk of bias evaluation was performed. Pooled standardised mean differences (SMD) and 95% confidence intervals (95% CI) were calculated. Ten studies involving 192 teeth were eligible for systematic review and meta-analysis could be performed with eight of these studies. Strong evidence showed that XP-Endo Finisher R file contributed significantly to filling material removal from root canals (SMD (95% CI): 0.41 (0.06-0.76)). Although the evidence was conflicting, XP-Endo Finisher R file was superior than other irrigant activation techniques (SMD (95% CI): 0.47 (0.02-0.93)). The supplementary use of XP-Endo Finisher and XP-Endo Finisher R is beneficial in further removal of root canal filling materials from root canal system.

Background.This study compared the effect of smear layer on the penetration depth and push-out bond strength of various root canal sealers. Methods.A total of 90 extracted human mandibular premolars were assigned into 2 groups: smear layer preserved and smear layer removed. Then the roots were further divided into 3 subgroups according to the sealer tested: AH 26, BioRoot RCS and MTA Plus. Obturation was performed with gutta-percha and the relevant sealer was mixed with 0.1% rhodamine B. Three 1-mm-thick slices were obtained from the mid-third area of each root. Two slices were selected for the push-out test and the remaining slice was used to calculate the dentinal tubule penetration depth and percentage. Results.The retention of MTA Plus and BioRoot RCS was higher than that of AH 26 when the smear layer was preserved (P

Objectives The purpose of this study was to conduct a systematic review and meta-analysis of in vitro studies regarding the effectiveness of reciprocating and rotary instrumentation on microbial reduction in root canals. Materials and methods PubMed, Scopus, Web of Science, the Cochrane Library, and the gray literature were searched through December 2019. Studies comparing the influence of reciprocating and rotary instrumentation on the removal of microorganisms from root canals that quantified the antimicrobial effect were included. Data extraction was completed using a systematic form for data collection. The risk of bias of the studies was evaluated. Standardized mean differences (SMDs) and confidence intervals (CIs) were calculated using a random effects meta-analysis. Results Seventeen in vitro studies were included in this systematic review, of which 7 provided adequate data for inclusion in the meta-analysis. Both reciprocating and rotary systems were similarly effective in reducing the microbial load in infected root canals (SMD [95% CI], 0.0481 [-0.271, 0.367]). Three studies showed a low risk of bias, whereas most of the studies (82%) presented a medium risk. Conclusions Although both techniques decrease the microbial content (with reductions of 23.32%-88.47% and 23.33%-89.86% for reciprocating and rotary instrumentation, respectively), they are not able to provide complete disinfection of root canals.

Separated root canal instruments may affect the quality of root canal obturation and hence the survival of endodontically treated teeth. Obturation techniques may influence filling-quality. The aim was to evaluate the obturation quality of teeth filled with different obturation techniques in the presence of apically separated instruments using micro-computed tomography (μ-CT). Notched ProTaper F2 rotary-files were separated in the apical third of 36-human mandibular incisors with single root/canal and mature apex. Samples were filled by an endodontist according to one of the following obturation techniques (n = 12): cold lateral-compaction (CLC), single-cone (SC) and thermoplastic injection (TI). Samples were scanned by the Skyscan 1,274® μ-CT device after 1-week at 37°C in 100% humidity. Images of the sections were evaluated with CTan software in terms of total-volume and volume percentage of the filling materials and voids between coronal end of the separated instrument and gutta-percha/sealer filled void-free sections. Data was analyzed using Kruskal-Wallis and Mann Whitney-U tests with a significance level of 5%. Kruskal-Wallis revealed differences among groups (p 0.05). Percentages of volumes of voids and filling materials were as follows for SC, CLC and TI, respectively: 8.88 ± 18.52% and 24.45 ± 38.40%, 46.92 ± 33.53% and 53.07 ± 33.53%, 40.54 ± 33.85% and 42.79 ± 34.45%. The obturation technique may have a significant impact on the volume of voids in the presence of a separated file. No obturation technique produced a void-free root canal filling.

The purpose of this study was to systematically review and critically analyze the published data of in vitro studies testing the effect of root canal sealers on the fracture resistance of endodontically treated teeth. A comprehensive literature search was performed by using the Medline, Scopus, Web of Science, Cochrane, and Open Grey databases. A hand search of the reference lists of identified articles was also performed. Two reviewers critically assessed the studies for eligibility against inclusion and exclusion criteria and performed data extraction. Evaluation of the risk of bias of the studies was performed. A total of 48 studies were assessed for eligibility. Of these, 20 met the inclusion criteria and were included in the systematic review. All studies had a medium or high risk of bias. Although the majority of the studies reported that the use of root canal sealers increased the fracture resistance of endodontically treated teeth, conflicting evidence was found for the reinforcing effect of resin, glass ionomer, and calcium silicate-based sealers while there was moderate evidence for zinc oxide eugenol-based sealers in favor of no reinforcing effect. On the basis of available evidence, the use of root canal sealer increases the fracture resistance of endodontically treated teeth. However, included studies presented considerable risk of bias. Regarding the comparisons among the sealers, no conclusions could be drawn for the superiority of one sealer type to another. A considerable heterogeneity was found in the methodologies of included studies. Therefore, this review strongly suggests the development of standardized methods to test the reinforcement effect of root canal filling materials in in vitro studies.

WOS: 000431942400031, PubMed: 29550008, Introduction: This study assessed the fracture resistance (FR) of teeth with simulated perforating internal resorption cavities repaired with different calcium silicate based cements (CSCs) and backfilling materials. Methods: Ninety-six mandibular premolar teeth were used. Twelve of the teeth were assigned as negative control group. Remaining roots were instrumented with rotary files, and standardized internal resorption cavities were prepared on the middle half of roots with burs. Twelve of the samples were not further interfered and were assigned as a positive control group. The apical 4 mm of the remaining 72 root canals was obturated with single-cone technique and divided into 6 groups according to CSCs used for repairing of cavities and backfilling materials as follows: MTA + MTA, MTA + gutta-percha/sealer, Biodentine + Biodentine, Biodentine + gutta-percha/sealer, MTA Plus + MTA Plus, and MTA Plus + gutta-percha/sealer. Specimens were embedded in acrylic resin and then subjected to fracture testing. The forces when the fracture occurred were analyzed with analysis of variance and Bonferroni tests at P = .05. Results: No significant difference was found among CSCs irrespective of backfilling materials (P > .05). Groups MTA + gutta-percha/sealer, Biodentine + gutta-percha/sealer, and MTA Plus + gutta-percha/sealer showed significantly lower FR compared with groups MTA + MTA, Biodentine + Biodentine, and MTA Plus + MTA Plus, respectively (P < .05). The highest FR was observed in group Biodentine + Biodentine, and the lowest was in group MTA Plus + gutta-percha/sealer. FR of positive control group was statistically lower than groups completely filled with CSCs (P < .05), whereas FR of negative control group was statistically higher than the groups combined with gutta-percha and sealer (P < .05). Conclusions: The backfilling with CSCs may be a preferable material rather than gutta-percha/sealer combination for the roots with perforated internal resorptions.

The aim of this study was to evaluate the fracture resistance of simulated immature teeth after internal bleaching. The teeth were assigned as follows (n = 12/group); Group-1: The pulp chamber was filled with ProRootMTA and bleached intracoronally with sodium perborate mixed with 37% carbamide peroxide gel; Group-2: The pulp chamber was filled with ProRootMTA without bleaching; Group-3: The pulp chamber was filled with Biodentine and bleached intracoronally as Group-1; Group-4: The pulp chamber was filled with Biodentine without bleaching; and Group-5: Teeth received no intervention (control). The specimens were loaded vertically until root fracture occurred. The data were analysed with Kruskal-Wallis and Dunn tests. There was no significant difference between the fracture resistances of the experimental groups (P > 0.05). However, all experimental groups had significantly lower fracture resistance than the control group (P < 0.05). Neither the tested calcium silicate cements nor the bleaching procedures had a significant impact on fracture resistance values.

OBJECTIVE To investigate the effect of different irrigation protocols on microhardness (MH) and flexural strength (FS) values of young and aged crown dentin. BACKGROUND In addition to ageing, root canal irrigation might also affect the mechanical properties of coronal dentin walls. MATERIALS AND METHODS One hundred and twenty dentin bars (2 mm × 2 mm × 8 mm) were obtained from the crowns of extracted, non-caries, human molars of young and older patients (n = 60 bars; average patient ages: 16.7 and 65.4, respectively). Subgroups were formed as follows: 2.5%NaOCl(sodium hypochlorite)+5%EDTA(ethylenediaminetetraacetic acid), 2.5%NaOCl + 15%EDTA, 2.5%NaOCl, 5%EDTA, 15%EDTA and Saline. NaOCl and saline were used for 20 minutes and EDTA solutions for 1 minute. MH values of each sample were measured before and after the irrigation protocols. The same samples were also submitted for FS analysis. The data were statistically analysed. RESULTS Young samples had lower MH values at pre- and post-treatment compared to aged samples (P

Objectives The aim of this study was to investigate whether the diameter and direction of the plunger and simulation of the periodontal ligament (PDL) affected the stress distribution in endodontically treated premolars. Methods A fracture strength test was simulated via finite element analysis. A base model was set up, and the following parameters were modified: plunger diameter (3 mm vs. 6 mm), plunger direction (vertical vs. 135° angular to the central fossa), and PDL simulation. The analysis was conducted using the CosmosWorks structural analysis program, and the results are presented in terms of von Mises stresses. Results The smaller plunger increased the stresses at the contact area of the crown, but the plunger diameter had no effect on the stress distribution within the root. An angular plunger direction increased stresses within the root, as well as at the buccal cusp of the crown, compared with the vertical direction. Simulation of the PDL caused higher stress accumulation, especially in the cervical region of the root. Conclusions The plunger diameter had no effect on the stress distribution in the roots, whereas the plunger direction and PDL simulation did affect the stress distribution. More stringent standards can be established by taking such parameters into account when performing fracture testing in future studies.

EgeUn###, Background: HCV virus infections are one of the major health problems in the world that can cause cirrhosis and liver cancer at a higher rate than other hepatitis data. The aim of this study was to determine the prevalence of mixed infections with different HCV genotypes in Turkey and also to evaluate the current HCV genotype and subtype distributions by a multicentered assessment. Methods: The HCV genotype data of 17,578 hepatitis C patients collected from 23 centers from different geographic regions covering all Turkey were collected. The data included information about the HCV genotypes in the last 10 years (between 2007 and 2016), demographic properties of the patients and the methods/systems used to determine the genotypes. Results: Two hundred twenty-eight of the patients (1.3%) had mixed genotype. The most common mixed genotype combination was 1b + 4 (0.83%) followed by 1a + 1b (0.26%). Genotype distribution varies according to geographical regions. However, genotype 1 (82.92%) was the most common genotype in all regions and all years. This was followed by genotype 3 (7.07%) and genotype 4 (5.43%). A variety of methods were used by the centers including sequencing, pyrosequencing, real-time PCR, in-house RFLP, reverse hybridization (LIPA), and hybridization. Conclusions: Infection with mixed HCV genotypes in Turkey is uncommon. Genotype distribution varies according to geographic regions; the most common genotype 1 is encountered all over the country, while genotypes 3 and 4 are only in some of the centers. Since there is limited information about mixed HCV infection, further investigations are needed to determine the clinical importance of mixed HCV infection. © 2019 Verlag Klinisches Labor GmbH. All rights reserved.

Objective: The aim of this in vitro study was to evaluate the bond strength of a new calcium silicate cement, Neo MTA Plus (Avalon Biomed Inc. Bradenton, FL, U.S.A) by comparing ProRoot MTA and Biodentine. Material and Methods: Sixty dentin slices were instrumented to achieve a diameter of 1.3 mm. Group 1: white ProRoot MTA, group 2: Biodentine, group 3: Neo MTA Plus–G (powder mixed with gel), group 4: Neo MTA Plus–W (powder mixed with distilled water) were loaded into cavities. The push-out bond strength values were measured. Data were analyzed using Welch ANOVA with Bonferroni correction p = 0.05. Failure modes (adhesive, cohesive, and mixture) were analyzed. Results: The highest bond strength value was recorded in Neo MTA Plus mixed with gel (5.23 ± 1.78 MPa), whereas white ProRoot MTA (2.57 ± 0.66 MPa) had the lowest. Bond strength values of Neo MTA Plus mixed either with gel or with distilled water were statistically different from both white ProRoot MTA and Biodentine (2.61 ± 0.70 MPa) (p

In current dental practices, traditional restorative approaches may have relatively limited long-term survival and may be associated to diverse complications, such as allergy, pulpitis, or periodontal pathologies. To overcome these shortcomings, novel innovative strategies have been envisioned for tooth repair. During the two last decades, the extensive advances in our understanding of tooth development as well as stem cell research provide the foundation for exciting opportunities in dental tissue engineering. The replacement of lost teeth by engineered dental tissue appears as a fascinating goal. However, the feasibility remains an intriguing question. Is the challenge to create a new tooth acting as a substitute for lost tooth or to regenerate only part of this organ that is enamel, dentin, or dental pulp? Is it possible to exploit stem cells for transplantation purposes to promote matrix formation and mineralization in the framework of endodontic treatment? Finally, investigating the functional properties of pulpal stem cells is however mandatory to envision novel therapeutic dental strategies. In this review, we summarize the current knowledge of stem cells used for dental tissue engineering and discuss the ensuing challenges for regenerative dentistry.

The aim of this study was to evaluate the quality of the canal fillings performed by thermoplastic technique (Herofill) and cold lateral condensation (CLC) techniques in oval shaped canals following self-adjusting file (SAF) preparation using radiological, stereological, and microscopic evaluation methods. Twelve pairs of oval-shaped root canals were prepared with SAF and filled using CLC (n = 12) or the Herofill system (n = 12). The quality of the root canal filling was evaluated by (i) scoring bidirectional storage phosphor plate images, (ii) stereological (volumetric) analysis of cone beam computerized tomography (CBCT) images, and (iii) microscopic analysis of the cross-sectioned area of the canal and gutta-percha via image analysis software. Chi-square test, t-test, and Mann-Whitney U-tests were used respectively (p 0.05). Herofill was not superior to cold lateral compaction. Stereology can be used to obtain unbiased information about the volume of root canal fillings. Both filling techniques failed to achieve the desirable goal of 0% empty volume in all of the cases and all evaluation systems confirmed this result. SCANNING 38:427-433, 2016. © 2015 Wiley Periodicals, Inc.

Background: The effect of solvent and sealer type (BioRoot RCS [BRRCS], mineral trioxide aggregate [MTA] Fillapex, and AH26) on the root canal residues was evaluated by confocal laser scanning microscopy (CLSM). Materials and Methods: Distal root canals of 60 mandibular molars prepared up to ProTaper-F4 were filled using one of the sealers labeled with 0.1% rhodamine-B (n = 20 per sealer). Samples were divided into two according to reprocessing methods as follows: ProTaper Universal Reprocessing System (PTUR) or solvent plus PTUR. Samples were sectioned at 2–5 and 8 mm from the apex and the samples were observed under CLSM. Penetration depth, percent penetration depth, and percent penetration into canal walls were evaluated. Statistical analysis was performed using the repeated measures of the two-way ANOVA and Bonferroni post hoc test at P = 0.05. Results: The highest penetration depth was measured in BRRCS in all root canal thirds with or without chloroform addition. Percentage of penetration depth values of MTA Fillapex and BRRCS was statistically similar and higher than AH26 in all sections, except the apical section re-treated with the addition of chloroform. Conclusion: None of the sealers were completely removed. The type of sealant and the use of chloroform changed the amount of sealant remaining in the root canal system.

Introduction: The purpose of this study was to evaluate the effect of calcium hydroxide (Ca[OH]2) dressing on the dentinal tubule penetration of epoxy resin–based sealer (AH 26; Dentsply Maillefer, Ballaigues, Switzerland) and tricalcium silicate–based sealer (BioRoot RCS; Septodont, Saint Maurdes Fosses, France). Methods: Fifty-two single-rooted mandibular premolars were used. Four samples were assigned as the positive control. Twenty-four samples received Ca(OH)2 labeled with rhodamine B, whereas the rest did not. Ca(OH)2 was removed with passive ultrasonic activation and copious irrigation 2 weeks later. Samples were further subdivided into 2 groups, and root canal fillings were performed with a single ProTaper F4 gutta-percha cone (Dentsply Maillefer) combined with 1 of the tested sealers labeled with fluorescein green. After 2 weeks, samples were transversely sectioned at the apical, middle, and coronal levels. The penetration depth and percentage were evaluated via imaging software. Statistical analysis was performed using Kruskal-Wallis, Siegel Castellan post hoc, and Mann-Whitney U tests at P =.05. Results: The mean dentinal tubule penetration depth and percentage values were lowest in the apical third for both sealers. BioRoot RCS showed higher penetrability in all thirds compared with AH 26 (P .05). Conclusions: Passive ultrasonic activation and copious irrigation were insufficient in removing Ca(OH)2 from root canals. BioRoot RCS presented higher dentinal tubule penetration than AH 26 even in the presence of Ca(OH)2 residues. Ca(OH)2 remnants decreased both dentinal tubule penetration depth and the percentage of the tested sealers; however, a more drastic effect was observed for AH 26. © 2018 American Association of Endodontists

Objectives This study aimed to introduce the use of laser-induced breakdown spectroscopy (LIBS) for evaluation of the mineral content of root canal dentin, and to assess whether a correlation exists between LIBS and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) methods by comparing the effects of irrigation solutions on the mineral content change of root canal dentin. Materials and Methods Forty teeth with a single root canal were decoronated and longitudinally sectioned to expose the canals. The root halves were divided into 4 groups (n = 10) according to the solution applied: group NaOCl, 5.25% sodium hypochlorite (NaOCl) for 1 hour; group EDTA, 17% ethylenediaminetetraacetic acid (EDTA) for 2 minutes; group NaOCl+EDTA, 5.25% NaOCl for 1 hour and 17% EDTA for 2 minutes; a control group. Each root half belonging to the same root was evaluated for mineral content with either LIBS or SEM/EDS methods. The data were analyzed statistically. Results In groups NaOCl and NaOCl+EDTA, the calcium (Ca)/phosphorus (P) ratio decreased while the sodium (Na) level increased compared with the other groups (p < 0.05). The magnesium (Mg) level changes were not significant among the groups. A significant positive correlation was found between the results of LIBS and SEM/EDS analyses (r = 0.84, p < 0.001). Conclusions Treatment with NaOCl for 1 hour altered the mineral content of dentin, while EDTA application for 2 minutes had no effect on the elemental composition. The LIBS method proved to be reliable while providing data for the elemental composition of root canal dentin.

Objectives The aim was to evaluate dentinal crack formation after root canal preparation with ProTaper Next system (PTN) with and without a glide path. Materials and Methods Forty-five mesial roots of mandibular first molars were selected. Fifteen teeth were left unprepared and served as controls. The experimental groups consist of mesiobuccal and mesiolingual root canals of remaining 30 teeth, which were divided into 2 groups (n = 15): Group PG/PTN, glide path was created with ProGlider (PG) and then canals were shaped with PTN system; Group PTN, glide path was not prepared and canals were shaped with PTN system only. All roots were sectioned perpendicular to the long axis at 1, 2, 3, 4, 6, and 8 mm from the apex, and the sections were observed under a stereomicroscope. The presence/absence of cracks was recorded. Data were analyzed with chi-square tests with Yates correction. Results There were no significant differences in crack formation between the PTN with and without glide path preparation. The incidence of cracks observed in PG/PTN and PTN groups was 17.8% and 28.9%, respectively. Conclusions The creation of a glide path with ProGlider before ProTaper Next rotary system did not influence dentinal crack formation in root canals.

Objectives This study compared the ability of several techniques to remove calcium hydroxide (CH) from the root canal and determined the influence of CH residues on the accuracy of the electronic apex locator. Materials and Methods Root canals of 90 human maxillary lateral incisors with confirmed true working length (TWL) were prepared and filled with CH. The teeth were randomly assigned to one of the experimental groups according to the CH removal technique (n = 14): 0.9% saline; 0.9% saline + master apical file (MAF); 17% ethylenediamine tetraacetic acid (EDTA); 17% EDTA + MAF; 5.25% sodium hypochlorite (NaOCl); 5.25% NaOCl + MAF. Six teeth were used as negative control. After CH removal, the electronic working length was measured using Root-ZX (Morita Corp.) and compared with TWL to evaluate Root-ZX accuracy. All specimens were sectioned longitudinally, and the area of remaining CH (CH) and total canal area were measured using imaging software. Results The EDTA + MAF and NaOCl + MAF groups showed better CH removal than other groups (p < 0.05). Root-ZX reliability to prevent overestimated working length to be > 85% within a tolerance of ± 1.0 mm (p < 0.05). There was strong negative correlation between amount of CH residues and EAL accuracy (r = -0.800 for ± 0.5 mm; r = -0.940 for ± 1.0 mm). Conclusions The mechanical instrumentation improves the CH removal of irrigation solutions although none of the techniques removed the dressing completely. Residues of CH medication in root canals affected the accuracy of Root-ZX adversely.

Aim: To evaluate the effectiveness of various chelates used alone or in combination with sodium hypochlorite (NaOCl) in the removal of calcium hydroxide (Ca(OH)2 ) from root canals. Materials and Methods: The root canals of 72 mandibular incisors were prepared up to the ProTaper F2 file. Among these, six randomly selected teeth were used as negative and positive controls, while the root canals of the remaining 66 were filled with Ca(OH)2 paste for 1 week. Then, the experimental group specimens were divided into six groups (n = 11). The access cavities were reopened and the Ca(OH)2 paste in each group was removed using the following solutions: 2.5 mL ethylenediaminetetraacetic acid (EDTA; Group 1), 2.5 mL peracetic acid (PAA; Group 2), 2.5 mL QMix (Group 3), 2.5 mL NaOCl/2.5 mL EDTA (Group 4), 2.5 mL NaOCl/2.5 mL PAA (Group 5), and 2.5 mL NaOCl/2.5 mL QMix (Group 6). Digital photographs of longitudinally split specimens were imported into image analyzer software, and the amount of residual Ca (OH) 2 was recorded as a percentage of the overall canal surface area. The results were analyzed using Kruskal–Wallis and Conover–Dunn tests. Results: The canal walls in the positive control group were completely covered with Ca(OH) 2 compared with those in the negative control group. The lowest Ca(OH)2 removal efficiency was observed for Group 4 (P < 0.001), while Group 6 showed favorable results (P < 0.05). Conclusions: QMix combined with NaOCl can remove Ca(OH)2 from root canals as effectively as 17% EDTA and 1% PAA. The type and sequence of irrigants are more important than the total irrigant volume for effective Ca(OH) 2 removal.

WOS: 000409812300004, PubMed: 28955522, Purpose: To evaluate the alterations on the surface of gutta-percha cones (GPCs) on exposure to the different irrigation solutions and their possible antibacterial effect against Enterococcus faecalis. (E. faecalis) Materials and Methods: Disinfection ability of different solutions (5.25% sodium hypochlorite, 2% chlorhexidine, 1% peracetic acid, and QMix) were tested with 96 GPCs and the time of exposure to each solution was 5 and 10 minutes, respectively. GPCs used in this study were contaminated with E. faecalis. After disinfection, GPCs were placed in tubes containing the medium and incubated at 37 degrees C for 7 days. All tubes were visually checked for turbidity at 24-hour intervals. About 92 new GPCs were analyzed by means of SEM/EDS to assess the topography and chemical elements present on their surface. The data generated was analyzed using Pearson chi-square test, p< 0.05. Results: There were no significant statistical differences in disinfection quality between the irrigation solutions used on GPCs contaminated with E. faecalis (p> 0.05). SEM/EDS analyses showed no alteration in the superficial features of GPCs after treating with various irrigation solutions. Conclusion: QMix was found to be an effective agent for rapid disinfection of GPCs as well-known irrigation solutions. Irrigation solutions were found to have sterilized the GPCs after both 5 and 10 minutes of exposure.

Background: This study aimed to compare glide path preparation of different pathfinding systems and their effects on the apical transportation of ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland) in mesial root canals of extracted human mandibular molars, using digital subtraction radiography. Materials and Methods: The mesial canals of 40 mandibular first molars (with curvature angles between 25° and 35°) were selected for this study. The specimens were divided randomly into 4 groups with 10 canals each. Glide paths were created in group 1 with #10, #15 and #20 K-type (Dentsply Maillefer, Ballaigues, Switzerland) stainless steel manual files; in group 2 with Path-File (Dentsply Maillefer) #1, #2, and #3 and in group 3 with #16 ProGlider (Dentsply Maillefer) rotary instruments; in group 4 no glide paths were created. All canals were instrumented up to ProTaper Next X2 to the working length. A double digital radiograph technique was used, pre and post-instrumentation, to assess whether apical transportation and/or aberration in root canal morphology occurred. Instrument failures were also recorded. The data were analyzed statistically using ANOVA and Tukey tests ( p 0.05). Two ProTaper Next instruments failed in-group 4. Conclusions: Within the parameters of this study, there was no difference between the performance of path-finding files and ProTaper Next system maintained root canal curvature well and was safe to use either with path-finding files or alone.

Objectives To determine the effect of size and insertion depth of irrigation needle on the amount of apical extruded debris and the amount of penetration depth of sealer using a confocal laser scanning microscope (CLSM). Materials and Methods Twenty maxillary premolars were assigned to 2 groups (n = 10), according to the size of needle tip, 28 G or 30 G. Buccal roots of samples were irrigated with respective needle type inserted 1 mm short of the working length (WL), while palatal roots were irrigated with respective needle type inserted 3 mm short of the WL. Prepared teeth were removed from the pre-weighed Eppendorf tubes. Canals were filled with F3 gutta-percha cone and rhodamine B dye-labeled AH 26 sealer. Teeth were transversally sectioned at 1 and 3 mm levels from the apex and observed under a CLSM. Eppendorf tubes were incubated to evaporate the irrigant and were weighed again. The difference between pre- and post-weights was calculated, and statistical evaluation was performed. Results Inserting needles closer to the apex and using needles with wider diameters were associated with significantly more debris extrusion (p < 0.05). The position of needles and level of sections had statistically significant effects on sealer penetration depth (p < 0.05 for both). Conclusions Following preparation, inserting narrower needles compatible with the final apical diameter of the prepared root canal at 3 mm short of WL during final irrigation might prevent debris extrusion and improve sealer penetration in the apical third.

The aims were to evaluate the effects of different additives on the adaptation of mineral trioxide aggregate (MTA) plugs before and after different backfilling techniques and analyze the interference of filling procedures on the fracture resistance of simulated immature teeth. The apical parts of 60 teeth were filled with MTA mixed with distilled water (DW), propylene glycol (PG) or calcium chloride (CaCl2) and backfilled with cold lateral condensation (CLC) or warm vertical compaction (WVC). The specimens were subjected to adaptation analysis and fracture testing. CaCl2 addition resulted in poor marginal adaptation, while PG addition significantly decreased the fracture values (p

Aim The aim of this in vitro study was to assess the amount of apically extruded debris and irrigant using Reciproc vs self-adjusting file (SAF) and to investigate the effect, if any, of gravitational force via mandibular and maxillary positioning of the teeth. Materials and methods Forty human mandibular premolars were randomly assigned to four groups of 10 teeth each. The root canals were instrumented according to the manufacturers’ instructions using the Reciproc and SAF. Sodium hypochlorite was used as the irrigant. The apically extruded debris was collected in pre-weighted glass vials using the Myers and Montgomery method, and teeth were placed in vials both in downward and upward positions. After drying, the mean weight of debris was assessed with a microbalance and statistically analyzed using two-way ANOVA with Bonferroni correction. Results All instrumentation techniques and positions caused measurable apical extrusion of debris. A significant difference was observed according to position and instrument used (p < 0.05). The Reciproc extruded significantly more debris than SAF and vial downward position extruded significantly more debris than upward position (p < 0.05). Conclusion Under the conditions of this study, all systems caused apical debris extrusion, especially in the downward position. Clinical significance According to results of this study, the SAF was associated with less debris extrusion compared to the Reciproc in both mandibular and maxillary positions. How to cite this article Uzunoglu E, Görduysus M. Apical Extrusion of Debris and Irrigant using Novel Preparation Systems. J Contemp Dent Pract 2014;15(4):423-427.

Introduction The aim of this in vitro study was to evaluate the amount of apically extruded bacteria associated with several root canal preparation systems. Methods Forty-four extracted human mandibular premolar root canals were contaminated with an Enterococcus faecalis suspension. After incubation at 37°C for 24 hours, the root canals were instrumented using the Twisted File (SybronEndo, Orange, CA), OneShape (Micro Mega, Besançon, France), and ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland). During instrumentation, apically extruded bacteria were collected into vials containing 0.9% NaCl. The microbiological samples were taken from the vials and incubated in brain-heart agar medium for 24 hours. The numbers of colony-forming units were determined. The data obtained were analyzed using Welch analysis of variance followed by post hoc Games-Howell tests. Results ProTaper Next extruded the highest amount of bacteria, whereas OneShape extruded the least compared with all the other instruments (P =.004). There was a significant difference between OneShape and ProTaper Next in the number of colony-forming units (P =.007) but not between OneShape and Twisted File (P >.05). Conclusions All instrumentation systems extruded bacteria beyond the foramen. The OneShape system extruded less bacteria compared with the Twisted File and ProTaper Next systems. © 2015 American Association of Endodontists.

Objectives This study evaluated the effects of intraradicular moisture on the pushout bond strength of a fibre post luted with several self-adhesive resin cements. Materials and Methods Endodontically treated root canals were treated with one of three luting cements: (1) RelyX U100, (2) Clearfil SA, and (3) G-Cem. Roots were then divided into four subgroups according to the moisture condition tested: (I) dry: excess water removed with paper points followed by dehydration with 95% ethanol, (II) normal moisture: canals blot-dried with paper points until appearing dry, (III) moist: canals dried by low vacuum using a Luer adapter, and (IV) wet: canals remained totally flooded. Two 1-mm-thick slices were obtained from each root sample and bond strength was measured using a push-out test setup. The data were analysed using a two-way analysis of variance and the Bonferroni post hoc test with p = 0.05. Results Statistical analysis demonstrated that moisture levels had a significant effect on the bond strength of luting cements (p < 0.05), with the exception of G-Cem. RelyX U100 displayed the highest bond strength under moist conditions (III). Clearfil SA had the highest bond strength under normal moisture conditions (II). Statistical ranking of bond strength values was as follows: RelyX U100 > Clearfil SA > G-Cem. Conclusions The degree of residual moisture significantly affected the adhesion of luting cements to radicular dentine.

Aim: The aim of this study was to evaluate the influence of different endodontic materials and final irrigation regimens on vertical root fracture (VRF) resistance.Materials and Methods: Eighty human teeth were prepared then assigned into two groups (n = 40) according to the final irrigations. G1: 5 mL, 5.25% sodium hypochlorite (NaOCl), G2: 5 mL, 2% chlorhexidine gluconate (CHX). Each group was assigned into four subgroups according to the obturation system used (n = 10): A: iRoot SP/single gutta‑percha cone (SGP), B: Only iRoot SP, C: Mineral trioxide aggregate (MTA)‑Fillapex/SGP, D: AH26/SGP. The specimens were embedded in acrylic molds and subjected to compressive loading at a rate of 1 mm min until VRF occurred. Data were analyzed via three‑way ANOVA tests.Results: The statistically significant difference was found among groups (P < 0.05). The G1A and G1B and G1D revealed significantly higher‑VRF values than G1C (P = 0.023). The roots filled with MTA‑Fillapex revealed lower‑VRF values than the other subgroups (P < 0.05). Groups irrigated with NaOCl had significantly lower‑VRF values than the groups irrigated with CHX (P < 0.05).Conclusion: Final irrigation regimens could alter VRF resistance of root canals filled with different obturation technique and root canal sealers.Key words: Chlorhexidine gluconate, root canal sealers, sodium hypochlorite, vertical root fracture

Objective: To evaluate the influence of manual and mechanical mixing techniques as well as the effects of moisture on the push-out bond strength of ProRoot MTA (Dentsply Tulsa Dental, Tulsa, OK, USA) and Biodentine (Septodont, Saint Maur des Fosses, France) to radicular dentin.Material and methods: Two hundred and forty dentin discs were assigned into three groups with respect to the moisture condition tested: (1) dry, (2) paper points, (3) wet. The discs were further divided into four subgroups according to the calcium silicate cements (CSCs) and mixing techniques used: (1) ProRoot MTA mixed manually, (2) ProRoot MTA mixed mechanically, (3) Biodentine mixed manually, and (4) Biodentine mixed mechanically. Bond strengths of the cements to root canal dentin were measured using a push-out test setup. The data were statistically analyzed using three-way ANOVA and Bonferroni post hoc test p = 0.05.Results: The data indicated that the push-out bond strength values were significantly affected by CSCs, mixing techniques, and moisture conditions (p < 0.001). Dry conditions caused a significant decrease in bond strength values for both CSCs (p < 0.001). The mean bond strength of Biodentine was significantly higher than that of ProRoot MTA, regardless of the mixing techniques and moisture conditions (p < 0.001). Mechanical mixing favored bond strength values statistically compared to manual mixing (p

Objective: The goal of present study was to determine the effect of different nickel–titanium file systems on the amount of apically extruded debris during endodontic retreatment: D-RaCe retreatment systems, EdgeFile XR retreatment rotary files, and Reciproc R40. Materials and Methods: Thirty-six single-rooted prepared mandibular premolar teeth were filled with Gutta-percha and AH Plus sealer. The teeth were then randomly assigned into three groups (n = 12) for retreatment. The endodontic retreatment was performed as follows: D-RaCe, EdgeFile XR, Reciproc 40. Debris extruded apically during the retreatment was collected into preweighed Eppendorf tubes. An incubator was used to store tubes at 70°C for 5 days. The initial weight was subtracted from final weight of the Eppendorf tubes to calculate the weight of the dry extruded debris for each group. The data obtained were evaluated using Welch analysis of variance and Games-Howell post-hoc tests (P < 0.05). Results: All files resulted in apical extrusion of debris. Reciproc caused significantly less debris extrusion compared to D-RaCe and EdgeFile XR (P < 0.05). Conclusions: The findings revealed that during endodontic retreatment, number, and taper of files might have an influence on the amount of apically extruded debris during endodontic retreatment.

Aim To evaluate the effect of powder-to-water ratio on the retention characteristics of white mineral trioxide aggregate (MTA; Angelus, Londrina, Pr, Brazil) over time. Methods One hundred and thirty-five root dentin slices from extracted single-rooted human mandibular premolar teeth were instrumented to achieve a diameter of 1.3 mm. Three MTA groups were prepared using 4:1, 3:1, and 2:1 powder-to-water ratios. The samples were stored for 96 h and 7 and 28 days at 37°C. The push-out bond strengths were measured using an Instron testing machine. Data were analyzed using two-way analysis of variance (anova) with Bonferroni correction. Results There was a statistically significant difference between the experimental groups at the 96-h and 7-day study periods (P = 0.002). At 96 h, the materials prepared at 2:1 ratio had the lowest bond strength than the samples prepared at the other two ratios (P

Results: Statistically significant differences between groups were detected (P .05). The majority of samples were fractured catastrophically in a labiolingual direction. Conclusion: The prepared samples were more prone to vertical root fracture compared with the unprepared samples. Neither motion kinematics nor the alloys of the files significantly influenced the fracture resistances of the prepared roots.

The aim of this study was to evaluate the effectiveness of 2.5 % NaOCl at different temperature and time intervals on Enterococcus faecalis and Candida albicans-infected human roots. A total of 112 root cylinders prepared from extracted single-rooted humans were infected by E. faecalis (Group A, n = 56) or C. albicans (Group B, n = 56); 3 root cylinders served as negative controls. Both groups were further divided into 6 subgroups according to three contact times (30 s, 1 min, 5 min) with NaOCl at two different temperatures (25 or 37 °C). Microorganism growth was controlled at the 24th and 48th hours. Statistical analysis was performed using the Chi-square test. While NaOCl at 25 °C for 5 min was the most effective irrigation regimen to eliminate E. faecalis (p < 0.001), NaOCl at 37 °C for 5 min exhibited significantly superior antifungal properties (p < 0.05). At the same contact times, difference in the temperature of NaOCl did not affect the growth of either E. faecalis or C. albicans. As a result, the irrigation time of NaOCl was more effective than the temperature to eliminate E. faecalis, while pre-heating of NaOCl to 37 °C increased its effectiveness on C. albicans at 5 min contact time.

Objective: To evaluate the amount of apically extruded debris during retreatment (with or without solvent) of root canals filled by two obturation techniques.Materials and Methods: Forty‑eight root canals were prepared using ProTaper Universal F3 and filled with Gutta‑percha and AH 26 sealer using single cone or lateral condensation techniques. The root canal fillings were removed using ProTaper Universal Retreatment system with or without solvent, and the canals were further prepared with ProTaper F4. The operating time was measured. The debris extruded was collected into preweighed Eppendorf tubes. The dry weight of the extruded debris was calculated by subtracting the weight of the empty tube from that of the tube containing debris. Statistical analysis was performed with two‑way analysis of variance test, with Bonferroni correction at a 95% confidence level.Results: There was no statistically significant difference in the amount of extruded debris between the two obturation techniques (P = 0.332). The mean amount of debris was higher in the nonsolvent groups than the solvent groups, particularly with the single cone technique (P = 0.013). There was a significant difference between groups with regard to the retreatment time (P < 0.001). Gutta‑percha removal took less time in the single cone group than in the lateral condensation group (P < 0.001). Gutta‑percha removal in the nonsolvent groups took significantly less time than that in the solvent groups (P < 0.001).Conclusions: The amounts of apically extruded debris were similar in both obturation techniques. A greater amount of apically extruded debris was observed in the nonsolvent groups than the solvent groups.Keywords: Apical Extrusion, Retreatment, Solvent

The purpose of this study was to compare the effect of different final irrigation solutions on fracture resistance values (FRVs) of endodontically treated teeth.Eighty extracted decoronated human incisors were used. Ten randomly selected roots were used as the negative control group. The remaining roots were prepared by the ProTaper system (Dentsply Maillefer, Ballaigues, Switzerland) up to F2. Ten prepared roots were selected as the positive control. The other prepared roots were divided into 6 (n = 10) groups according to the final irrigation solution used: 5 mL saline, 17% EDTA, EDTA with a surfactant (REDTA), chlorhexidine, QMix (Dentsply Tulsa Dental Specialties, Tulsa, OK), and BioPure MTAD (Dentsply Tulsa Dental Specialties). In all groups, the final irrigation was performed for 1 minute except for the BioPure MTAD group; in this group, it was applied for 5 minutes according to the manufacturer's instructions. The specimens were filled with a single gutta-percha cone and AH 26 sealer (Dentsply, De Trey, Konstanz, Germany). After being stored under 37 °C and 100% humidity for a week, the specimens were loaded in a vertical direction at 1 mm/min speed until they were vertically fractured. The results were analyzed by the Kruskal-Wallis and Siegel Castellan tests.The negative control group showed the highest FRV. There were statistically significant differences between the negative and positive control groups (P.05). Specimens irrigated with REDTA and QMix showed a higher FRV compared with the positive control group (P.05). Specimens exposed to chlorhexidine and BioPure MTAD showed a lower FRV compared with the negative control group (P.05).Root canal preparation weakens the tooth. The final irrigation regimen has an impact on the FRV. A short time exposure to irrigation solutions (REDTA and QMix) that include surfactants probably contributed to the higher FRV, instead of a long time exposure as done with BioPure MTAD.