Master Apical File Research Articles

Comparative evaluation of the shaping ability of rotary systems of varying metallurgy in curved canals and its analysis using cone-beam computed tomography: An in vitro study

Background: This study compared the shaping ability of four nickel-titanium rotary file systems of varying metallurgy along curved canals. Aim: The aim of the present study is to compare the shaping ability of rotary systems of varying metallurgy in curved canals and its analysis using cone-beam computed tomography (CBCT). Materials and Methods: Forty mesiobuccal canals of mandibular first molars with an angle of curvature ranging from 20° to 40° were divided according to the instrument used in canal preparation into four groups of 10 samples each: Hyflex CM (Group I), Vortex Blue (Group II), Flexicon (Group III), and K3XF (Group IV). All samples were instrumented according to the manufacturer's guidelines and prepared to size 30, 0.06-taper master apical file. Canals were scanned and evaluated using an NNT CBCT unit before and after preparation at different levels from the apex. The data were subjected to statistical analysis. Statistical Analysis: The intergroup comparison in terms of canal transportation and the time taken for canal preparation was done by the one-way analysis of variance (ANOVA) test with Bonferroni post hoc test. The intragroup comparison in terms of canal transportation was done by the repeated measures ANOVA test with the post hoc Bonferroni test. For the canal-centering ability, the Kruskal–Wallis test with Mann–Whitney U-test was used for the intergroup comparison and the intragroup comparison was done by Friedman's test with Wilcoxon signed-rank test. Results: Hyflex CM and Vortex Blue files showed significantly least canal transportation and highest canal-centering ability values as compared to Flexicon and K3XF file systems. Conclusion: The metallurgy and file design of Hyflex CM and Vortex Blue file systems resulted in superior shaping ability, with the instruments remaining more centered in the canal than Flexicon and K3XF.

Fracture resistance of roots enlarged with various rotary systems and obturated with different sealers.

Background. This in vitro study compared the fracture resistance of roots instrumented either with ProTaper or One Shape rotary systems and filled with one of the silicate, epoxy resin or silicone-based sealers. Methods. Sixty single-rooted extracted mandibular premolars were decoronated to a length of 13 mm and then randomly divided into two main groups (n=30) in terms of the rotary system used for preparation. Group 1 samples were instrumented with the ProTaper Universal system up to a master apical file of #F2, while samples in group 2 were enlarged with One Shape system. The two main groups were then divided into 3 subgroups in terms of the sealer used (n=10) and filled with guttapercha (either F2 or MM-GP points) of the rotary system used and one of the sealers as follows: group 1, BioRoot RCS + ProTaper F2 gutta-percha; group 2, AH Plus + ProTaper F2 gutta-percha; group 3, GuttaFlow + ProTaper F2 gutta-percha; group 4, BioRoot RCS+ MM-GP points; group 5, AH Plus + MM-GP points; and group 6, GuttaFlow + MM-GP points. Each specimen then underwent fracture testing by using a universal testing machine at a crosshead speed of 1.0 mm/min until the root fractured. Data were statistically analyzed. Results. Two-way ANOVA showed no significant differences between the groups. One Shape instruments showed significantly better fracture resistance compared to ProTaper instruments. Statistically, no significant difference was found between AHPlus, GuttaFlow and BioRoot RCS sealers. Conclusion. It can be concluded that the rotary system used for the instrumentation of teeth has some influence on the fracture resistance, while the root canal sealers do not have such an effect.

Antibacterial activity of chitosan and its combination with other irrigants on Enterococcus faecalis: An in vitro study

Objective: The aim of the in vitro study was to compare the antibacterial efficacy of sodium hypochlorite (NaOCl), chlorhexidine (CHX), chitosan and their combinations in vitro. Materials and Methods: A total of 60 extracted single-rooted teeth were selected and used for the study. After the access cavity preparation and working length determination, the apical foramina of the samples were sealed with epoxy resin to prevent bacterial leakage, and the teeth were mounted in stone blocks. Biomechanical preparation was done using crown-down technique up to master apical file size of #50. Enterococcus faecalis (ATCC 29212) was used to contaminate the root canals. After incubation, samples were divided into six groups according to the solutions used for irrigation, that is, CHX, NaOCl, chitosan, alternating solution of chitosan and hypochlorite, alternating solution of chitosan and CHX, and saline. Antibacterial efficacy was assessed by obtaining the samples from root canal before and after the irrigation using paper points, culturing them on blood agar plates, and measuring the number of colony-forming units (CFUs) formed. Results: All the statistical analysis was done using SPSS version 16. P 0.001). Maximum antibacterial activity was seen when chitosan was used alternatively with CHX and NaOCl. Independently, hypochlorite showed maximum antibacterial activity followed by CHX and chitosan which showed almost similar antibacterial activity. Conclusion: According to this study, there is synergistic antibacterial activity when chitosan is used alternatively with 2% CHX or 5% NaOCl.

A micro-computed tomographic study of remaining filling materials of two bioceramic sealers and epoxy resin sealer after retreatment.

ObjectiveThis study evaluated the presence of residual root canal filling material after retreatment using micro-computed tomography (micro-CT).Materials and MethodsExtracted human teeth (single- and double-rooted, n = 21/each; C-shaped, n = 15) were prepared with ProFile and randomly assigned to three subgroups for obturation with gutta-percha and three different sealers (EndoSeal MTA, EndoSequence BC sealer, and AH Plus). After 10 days, the filling material was removed and the root canals were instrumented one size up from the previous master apical file size. The teeth were scanned using micro-CT before and after retreatment. The percentage of remaining filling material after retreatment was calculated at the coronal, middle, and apical thirds. Data were analyzed using the Kruskal-Wallis test and Mann-Whitney U test with Bonferroni post hoc correction.ResultsThe tested sealers showed no significant differences in the percentage of remaining filling material in single- and double-rooted teeth, although EndoSeal MTA showed the highest value in C-shaped roots (p < 0.05). The percentage of remaining filling material of AH Plus and EndoSeal MTA was significantly higher in C-shaped roots than in single- or double-roots (p < 0.05), while that of BC sealer was similar across all root types. EndoSeal MTA showed the highest values at the apical thirds of single- and double-roots (p < 0.05); otherwise, no significant differences were observed among the coronal, middle, and apical thirds.ConclusionsWithin the limitations of this study, a large amount of EndoSeal MTA remained after retreatment, especially in C-shaped root canals.

“Efficiency of removal of debris from root canal system with help of different irrigation system:” An in vitro scanning electron microscope study

Aims and Objectives: The aim of this study was to determine the efficiency of EndoActivator, passive ultrasonic irrigation, side-vented needle, and syringe irrigation for removal of dentinal debris (smear layer) in root canals prepared with same master apical file sizes. Materials and Methods: Forty mandibular premolars with mature apices (extracted) were selected for this study. Each tooth was decoronated 2mm coronal to the cementoenamel junction with a diamond disk to facilitate straight-line access for instrumentation. Apical patency was determined by inserting an ISO # 08 K-file. Working length was determined by placing a size 15 K-file into the canal until it appeared at the apical foramen; this length was measured and the working length was set at 1mm short of this measurement. The roots were sealed with yellow sticky wax (DPI) to avoid apical extrusion during irrigation. The root canals were prepared to size 40, 0.02 taper, using step-back technique. After each instrument change, manual irrigation was performed with 2-mL NaOCl (3%) using a 26-gauge syringe. Then, a total of 40 samples were randomly distributed into four groups. According to group, root canals were irrigated with EndoActivator, passive ultrasonic irrigation, side-vented needle, and syringe irrigation. The roots were spilt and sent laboratory for examination under scanning electron microscope. Results: Ultrasonic irrigation had highest removal of the smear layer than the other irrigation systems followed by EndoActivator, side-vented needle, and syringe irrigation. Conclusion: Ultrasonic irrigation resulted in better removal of the smear layer in the apical third of root canals than EndoActivator, side-vented needle, and conventional needle irrigation.

Evaluation of Apical Transportation During Calcium Hydroxide Paste Removal Using 2 Different Rotary Systems-invitro study

Objectives: This study was done to compare and evaluate incidence of apical transportation during calcium hydroxide paste removal using 2 different rotary systems on 40 degree curved simulated root canal blocks. Materials and Methods: 2 groups (n=15 Group 1- iRace Group 2- ProTaper) of simulated root canals were instrumented till working length. Post instrumentation images were taken under stereomicroscope with corresponding final file inserted into the canal to the working length. Calcium hydroxide paste with iodoform was placed till the working length and removed after 7 days using Master Apical File with copious irrigation. Images were taken under stereomicroscope post calcium hydroxide paste removal with corresponding final file inserted till the working length to assess the incidence of apical transportation. Images were printed and the angle was measured using Schneider’s technique by 3 examiners. Stereomicroscopic images were superimposed using Adobe Photoshop 8 software to observe any deviation in the original path. Results: The mean angle change after rotary instrumentation and calcium hydroxide removal were observed in both groups. Superimposed images showed greater root canal deviation in Group 2 than Group1.

The effects of chelation on the adhesion of two different root canal sealers

Objective: This study aims to evaluate alterations in the root canal dentin after irrigation with EDTA, HEBP, and Chitosan in order to determine the push-out bond strengths of the different root canal sealers on altered dentin surfaces. Materials And Methods: Crowns of 70 maxillary single-rooted teeth were removed to obtain a standardized length of 16 mm. The canals were instrumented using rotary files and the step back technique. The master apical file used in this study was #40. The subgroups were determined based on the chelation agent and the material of the root canal sealer that was used (17% EDTA, 18% HEPB, 0.2% Chitosan, Well Root ST (WRST) or AH Plus). Three slices with 1 mm thickness were cut from the root thirds of each tooth and subjected to a push-out test. The data (MPa) were analyzed using a one-way ANOVA and a Duncan’s multiple comparison test at a level of α = 0.05. Finally, scanning electron microscope (SEM) photographs were taken. Results: Groups that used WRST exhibited significantly higher push-out bond strength values in all subgroups independent of the irrigant that was used (ANOVA, p < 0.05). Group 1 showed higher push-out bond strength than the other AH Plus subgroups. Conclusion: The EDTA improved the push-out bond strength of the AH Plus. The WRST root canal sealer had the highest push-out bond strength and did not depend on the irrigant used.

Size of Master Apical File and Optimal Irrigation of the Apical Zone: A Systematic Review.

To determine what would be the minimal apical diameter for optimal chemomechanical preparation in the root canal system in terms of debridement and/or irrigation delivery, in patients undergoing nonsurgical root canal treatment. Randomized controlled clinical trials, cohorts, cross-over studies from peer-reviewed journals published in English from January 1950 to June 2018 which reported outcome in terms of healing, microbial reduction and/or effectiveness of irrigation delivery to the apical third of the root canal system. Two reviewers conducted a comprehensive literature search. There were no disagreements between the two reviewers. The articles that met the inclusion criteria went through a predefined review process. Due to the variety of methodologies and different techniques used to measure outcome for master apical file enlargement, it was not possible to standardize the research data and to perform meta-analysis. Twelve clinical articles were identified that met the inclusion criteria. The overall level of evidence on this topic was moderate (fair). From this systematic review, the majority of the studies collected and referred to recommend sizes higher than #30 as the minimal size in order to adequately prepare the apical region of the root canals. Only 2 out of 12 studies suggested the size #25 as acceptable. From this systematic review it may be concluded that a larger MAF preparation above size 30 aids chemomechanical action.

"Evaluation of the antibacterial efficacy of EZLASE diode LASER on the infected root canal system:" An in vivo study.

Aims and Objectives:The aim of this in vivo study was to evaluate the antibacterial efficacy of a diode LASER on the infected root canal system.Methodology:A total of forty patients with infected root canals were selected. The root canals were prepared mechanically, and irrigation was done with 3% sodium hypochlorite (NaOCl). Microbiological samples were collected before LASER treatment with the help of the master apical file (MAF) to full working length for subsequent microbiological examination. The procedure was followed by laser treatment with an EZLASE diode LASER (940 nm), at different output powers. Following irradiation, samples were collected for microbiological examination. The samples were transferred to an agar plate and incubated for 48 h at 37°C. The colonies formed were then counted, and the total number of bacteria per ml before and after LASER application was assessed. Colony-forming unit (CFU/ml) was counted for Enterococcus faecalis and other bacterial flora from pretreatment and posttreatment samples that were then analyzed using the Kruskal–Wallis test and Mann–Whitney U-test.Results:The highest power of laser used (1.95 W) had resulted in maximum reduction of bacterial flora and E. faecalis counts.Conclusions:Combination therapy consisting of irrigation using NaOCl and LASER irradiation, especially at high output power was an effective treatment option for a reduction in E. faecalis as well as other bacterial flora from the root canal system.

APICAL CLEANLINESS AFTER REMOVAL OF TOTALFILL BIOCERAMIC SEALER VERSUS AH-PLUS EPOXY-RESIN SEALER

Objectives: The aim of the present study was to evaluate the apical cleanliness following canal enlargement after removal of canal obturating material containing TotalFill bioceramic Sealer as compared to AH-Plus epoxy-resin sealer. Materials & Methods: 40 obturated single-canal roots were divided into 2 groups; AH-Plus (Gp-I) and TotalFill (Gp-II) 15 specimen each. 5 specimens were kept as control for each group. Canal filling was removed and canals were enlarged. According to the file size used for canal enlargement, each group was divided into 3 sub-groups; A, B, and C (#30-0.04%, #35-0.04, and #35-0.04%, respectively). Roots were split and the apical third was examined under SEM. Digital image analysis was done for the photomicrographs. Results: SEM images of the control groups revealed more condensed and widely spread particles of TotalFill in comparison to AH-Plus. In AH-Plus subgroups: The recorded means (in a descending order) of remnants for subgroups I_A, I_B, and I_C were 27.3, 24.23, and 0.94, respectively. There was a significant statistical difference (P≤0.05) between the test subgroups, except for subgroups I_A/I_B where the difference was statistically insignificant (P > 0.05). In TotalFill subgroups: The recorded means (in a descending order) of remnants for subgroups II_A, II_B, and II_C were 48.16, 39.3, and 30.42, respectively. There was a statistically insignificant difference (P > 0.05) between the test subgroups, except for subgroups II_A/II_C, where the difference was statistically significant (P≤0.05). In file #40 sub-groups: There was a statistically significant difference (P≤0.01) between the recorded amount of remnants between AH-Plus and TotalFill subgroups. TotalFill recorded higher amount of remnants. Conclusions: Within the parameters of this study - after canal desobturation -, increasing the size of the apical preparation – within limits – improves the cleanliness of canal walls at the apical third area. TotalFill sealer leaves more remnants on the dentin surface of the apical third when compared to AH-Plus sealer. It’s better to enlarge the apical third of the canal two or three sizes larger than the master apical file (in case of desobturation of bioceramic-sealer-containing canal filling) to ensure better cleanliness of the area.

Radiographic Quality of Root Canal Obturation Performed By Fifth Year Students of Hamadan Dental School.

The aim of this study was to assess the radiographic technical quality of root canal therapy performed by fifth year students of Dental School of Hamadan University of Medical Sciences from 2015 to 2016. Four hundred and seventy records of root canal therapies were evaluated. Records with graphies taken as initial, master apical file (MAF), master apical cone (MAC) and final radiographs were included in the study and records of patient younger than 16 years and older than 68 years were excluded from further investigations. Lastly, 432 teeth were selected. Obturation length, canal tapering, quality and density of filling material were the variables investigated in the present study. Two independent investigators examined the radiographies using a magnifying lens (×2) and x-ray viewer. Data were analyzed using chi-square test. The technical quality of root filling performed by undergraduate dental students was classified as acceptable in 10.4% of cases. Moreover, 70.8% of teeth had adequate filling, 17.1% were underfilled and 12% were overfilled. The three groups were significantly different in terms of working length and taper quality. One hundred ninety four (44.9%) records had adequate taper and 109 (25%) records had adequate density. There was a significant association between teeth location and the length of obturation so that the probability of a successful treatment was higher in maxillary teeth. Furthermore, the rate of a proper length of obturation was higher among incisors than that of premolars and molars. The technical quality of root canal therapy performed by dental students in Hamadan University of medical sciences is not as acceptable as it should be. One of the most important factors in this regard is a high student/professor ratio.

Apical Transportation, Centering Ratio, and Volume Increase after Manual, Rotary, and Reciprocating Instrumentation in Curved Root Canals: Analysis by Micro-computed Tomographic and Digital Subtraction Radiography

IntroductionThis study aimed to evaluate apical transportation (AT), centering ratio (CR), and volume increase (VI) produced after instrumentation of mesiobuccal canals of maxillary molars with hand files, rotary, and reciprocating instruments using micro–computed tomographic (micro-CT) imaging and to demonstrate the ability of digital subtraction radiography (DSR) to evaluate AT. MethodsForty-five canals were randomly assigned to either group K, manual K-files; PTN, ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland); or Rec, Reciproc (n = 15 for each group) for preparation. Master apical files were #25, X2 (#25/06), and R25 (#25/08), respectively. Micro-CT imaging was used to measure AT (mm) and CR (mm) at 3 different locations (1, 4, and 7 mm from the apex). VI (mm3) was measured for each root third and for the whole canal. DSR (mesiodistal and buccolingual projections) was used to measure AT at 1 mm from the apex. ResultsAT and CR values were statistically similar across the groups at 1, 4, and 7 mm. AT results obtained for the different locations were similar within each group; CR, in turn, showed statistically lower values at 1 mm. VI was statistically similar in all groups. Both DSR and micro-CT imaging showed that AT always occurred on the outside of canal curvature. The highest mean value obtained for AT was 0.215 mm. ConclusionsAT, CR, and VI were similar for the K, PTN, and Rec groups. AT results were clinically irrelevant. DSR was as effective as micro-CT imaging in AT analysis and could be considered as an alternative method for assessing this outcome.

Incidence of dentinal defects during root canal preparation with hand files using different irrigants: An in vitro study.

Introduction:The purpose of this in vitro study was to compare the incidence of dentinal defects during root canal preparation with hand files using different irrigants.Materials and Methods:A total of 120 extracted mandibular incisors were randomly divided into onecontrol group and five experimental groups (n = 20) depending on the irrigant used. Biomechanical preparation was not done in control group. Teeth in experimental groups were prepared with hand K-files to a master apical file #35 with 1-mm increments step-back up to #50. In Group 2, saline was used as an irrigant. In Groups 3, 4, 5, and 6, 3% sodium hypochlorite (NaOCL), SmearClear, 17% ethylenediaminetetraacetic acid (EDTA), and 2% chlorhexidine (CHX), respectively, were used as an irrigant. Specimens were sectioned perpendicular to the long axis at 3, 6, and 9 mm from the apex. Sections were observed under a digital stereomicroscope at 30× magnification. Two-tailed t-test was used for statistical analysis.Results:There was a statistically significant difference between the six groups. Group 5 (17% EDTA) had the highest number of dentinal defects, followed by Group 3 (3% NaOCl), Group 4 (SmearClear), and Group 6 (2% CHX).Conclusions:17% EDTA causes more dentinal defects as compared to 3% NaOCl, SmearClear, 2% CHX, and saline.

Comparative evaluation of Fracture Resistance of Endodontically Treated Teeth Obturated with Pozzolan-based MTA Sealer and Epoxy Resin-based Sealer: An in vitro Study

ABSTRACT Aim To evaluate and compare the effect of epoxy resin-based sealer and a pozzolan-based mineral trioxide aggregate (MTA) sealer on the fracture resistance of endodontically treated teeth. Materials and methods Thirty single-rooted mandibular premolars were decoronated to a standardized root length of 15 mm. ProTaper rotary files up to a master apical file size of F3 were used for cleaning and shaping the root canals followed by 2.5% sodium hypochlorite irrigation. The teeth were randomly divided into three groups (n = 10 each), and the obturation was completed using gutta-percha with Endoseal MTA (group I) and AH Plus (group II) as root canal sealers. Group III served as control (instrumented and unfilled). Each specimen was then subjected to fracture testing by using a universal testing machine at a crosshead speed of 1.0 mm/minute until fracture. The force required to fracture each specimen was recorded and the data were subjected to statistical analysis using one-way analysis of variance (ANOVA), followed by pairwise comparison using post hoc Games-Howell test (p &lt; 0.05). Results The fracture resistance of groups I and II were significantly higher than those of group III. No significant difference in the fracture resistance was observed between group I (Endoseal MTA) and group II (AH Plus) groups. Conclusion It can be concluded that the new root canal sealer, Endoseal MTA, is able to reinforce the tooth against fracture as good as AH Plus. Clinical significance Endoseal MTA is a sealer for the reinforcement of endodontically treated teeth. How to cite this article Upadhyay ST, Purayil TP, Ginjupalli K. Comparative evaluation of Fracture Resistance of EndodonticallyTreated Teeth Obturated with Pozzolan-based MTA Sealer and Epoxy Resin-based Sealer: An in vitro Study. World J Dent 2017;8(1):37-40.

Dentin Bond Strength Evaluation of Three Root Canal Sealers with Cold Gutta-Percha Lateral Obturation Technique: Push-Out Test Study

Aim: This study was designed to evaluate dentin bond strength by push-out test of three root canal sealers (IRoot SP, AH Plus, and MTA Fillapex endodontic sealers) with cold gutta-percha lateral obturation technique using push-out test. Methods: A total of 57 human freshly extracted mandibular premolar teeth for orthodontic reason were used in this study. All samples were decoronated 16±1mm from the apex and prepared using step-back technique up to master apical file # 40. The specimens were divided randomly into three groups (19 teeth each) according to the type of sealers used; Group 1(IRoot SP), Group 2(AH Plus sealer), and Group 3 (MTA Fillapex sealer). Each group was obturated with cold gutta-percha lateral obturation technique. The specimens were incubated for 7 days at 37oC with 100% humidity. Three sections of 2 mm thickness were obtained at 3, 7 and 11mm from the apex to represent apical, middle and coronal thirdrespectively. The push-out bond strength was determined for each root slice. Values were recorded, tabulated for each group and statistically analyzed. Results: IRoot SP showed the highest mean value of push-out bond strength (7.3±0.2), followed by AH Plus (6.8±0.1) while MTA Fillapex showed the lowest mean value of push-out bond strength (2.9±0.3). Conclusions: IRoot SP and AH plus sealers had greater resistance to push-out than MTA Fillapex sealer.

The effects of different irrigation protocols on removing calcium hydroxide from the root canals.

The aim of this study was to evaluate the efficiencies of different irrigation protocols and solutions in the removal of calcium hydroxide (Ca[OH]2). Sixty-eight maxillary incisors were used. Root canals were prepared and filled with Ca(OH)2. Two control (n = 4) and six experimental groups (n = 10) were adjusted: Group 1:1% peracetic acid (PAA) + master apical file (MAF); Group 2: 17% ethylenediaminetetraacetic acid (EDTA) + MAF; Group 3: 9% 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) + MAF; Group 4: 1% PAA + ultrasonic activation (UA); Group 5: 17% EDTA + UA; Group 6: 9% HEBP + UA. The cleanliness of root canal thirds were evaluated with scanning electron microscopy. Statistical analysis were performed (α = 0.05). At coronal thirds; PAA + UA was superior to EDTA + MAF, HEBP + MAF; and PAA + MAF was superior to EDTA + MAF, HEBP + MAF (P < 0.05). At middle thirds; PAA + MAF and PAA + UA were superior to EDTA + MAF and EDTA + UA; and, PAA + UA was superior to HEBP + MAF (P < 0.05). There were no significant differences among the rest of the experimental groups (P > 0.05). Complete removal of Ca(OH)2could not be achieved by none of the irrigants at all root thirds.

EFFECT OF DIFFERENT IRRIGATING SOLUTIONS AND MECHANICAL AIDS ON THE REMOVAL OF CALCIUM HYDROXIDE INTRA-CANAL MEDICATION FROM STRAIGHT AND CURVED CANALS

aim: to study effect of different irrigating solutions and mechanical aids on Ca(OH)2 removal from straight and curved canals. materials and methods: Forty five maxillary central incisors with straight roots (group I) were prepared with step back technique until apical size 55 and forty five mandibular first molars with curved mesio buccal canals (group II) prepared with Pro Taper universal system up to apical size F2. Calcium hydroxide was applied into all canals and the accesses were sealed with temporary dressing. All teeth were placed in wax mould and digital radiographs were taken to confirm canal filling with Ca(OH)2 to length. Every group was subdivided into 3 subgroups according to the irrigating solution used; subgroup A irrigated with 5.25% NaOCl only, subgroup B irrigated with 5.25% NaOCl and 10% H2O2, and subgroup C irrigated with 5.25% NaOCl and 17% EDTA. Every subgroup was further subdivided into 3 subgroups (1, 2, and 3) according to the mechanical aid for Ca(OH)2 removal; in subgroup 1 used master apical file, in subgroup 2 used master apical file and apical patency, in subgroup 3 used master apical file, apical patency and increase in canal size. Post removal digital radiographs were taken for all teeth in their wax mould. Any traces of Ca(OH)2 were traced by “Image J” software and estimated as a percentage to the total canal space and statistically analyzed. results: There was no significant difference between the subgroups A, B, and C in anterior and posterior teeth either in subgroup 1, 2, or 3. In anterior teeth group, there were significant differences between subgroups 1, 2, and 3 in subgroup B and C but, in subgroup A, there was no significant difference. In posterior teeth group, there was a significant difference between subgroups 1, 2, and 3. in subgroup A but, in subgroup B and C, there was no significant difference. Anterior and posterior teeth were compared and the results were significant differences in subgroups A1 and A2 but, in subgroup A3 there was no significant difference. In subgroup B, there were significant differences in subgroups B1, B2 and B3. In subgroup C, there was no significant difference in subgroups C1, C2 and C3. conclusions: Under the tested conditions of this study, the most successful method of Ca(OH)2 removal was the use of master apical file (hand or rotary), apical patency and increase one size filing with the combination of EDTA and NaOCl irrigation in both anterior & posterior teeth.

Effect of apical clearing technique on the treatment outcome of teeth with asymptomatic apical periodontitis: A randomized clinical trial.

Aim:This study aims to compare the periapical healing of teeth with asymptomatic apical periodontitis treated either by conventional apical preparation (CAP) or apical clearing technique (ACT).Materials and Methods:Twenty subjects with bilateral nonvital similar teeth exhibiting comparable periapical index (PAI) score were enrolled and randomly allocated. Group I (CAP, n = 20): Apical preparation three sizes greater (master apical file [MAF]) than the first binding file at the established working length. Group II (ACT, n = 20): Apical preparation three sizes greater than the MAF that was followed by dry reaming. Root canal therapy was accomplished in single-visit for all the teeth. They were pursued radiographically at 3, 6, 9 and 12 months. Pre- and post-treatment PAI scores were compared. To ascertain the proportion of healed teeth between the two groups, McNemar Chi-square test was applied.Results:At 3, 6, and 9 months’ time interval the proportion of healed teeth for Group II (ACT) was greater in comparison to Group I (CAP) (P < 0.05). However, at 12 months follow-up period this difference was not significant (P = 0.08).Conclusion:ACT enhanced the healing kinetics. However, the long-term (12 months) radiographic outcome was similar for either technique.

A comparison of apical sealing ability between GuttaFlow and AH plus: An in vitro study.

Aims:The present study aimed to compare apical sealing ability between GuttaFlow and AH Plus.Materials and Method:Eighty extracted human maxillary anterior teeth with fully formed apex and straight root were collected for this study. The root canals were cleaned and shaped using a standard step back preparation to size 60# master apical file at the established working length and divided into four groups: Group 1, GuttaFlow sealer with gutta-percha; Group 2, AH Plus sealer with gutta-percha; Group 3, positive control group (Teeth were instrumented and left without obturation); Group 4, negative control group (Teeth were totally coated with nail varnish) Dye leakage was carried out. Statistical analysis was done using the Statistical Package for the Social Sciences software and Student's unpaired t-test.Results:The GuttaFlow group had a mean leakage of 1.38 mm whereas AH Plus had a mean of 1.425 mm. The standard deviation of GuttaFlow and AH Plus were 0.3861 and 0.3226, respectively. Student's unpaired t-test disclosed no significant difference (P < 0.05) between the groups.Conclusion:None of the sealers used in the study could completely seal the apical foramen to have a fluid-tight seal. GuttaFlow and AH Plus showed no statistically significant difference in microleakage; the better result was shown by GuttaFlow.

Comparative evaluation of fracture resistance of teeth obturated using three different systems – AH plus/Gutta-percha, Resilon/Realseal self-etch, and Endofill/Gutta-percha: Anin vitrostudy

Introduction: Endodontically treated teeth are more prone to fracture under masticatory forces. Resin-based dental materials have been proposed as a means to reinforce an endodontically treated tooth through the use of adhesive sealers in the root canal system. Aims: The objective of this study is to evaluate the fracture resistance of endodontically treated teeth obturated using lateral compaction technique with AH plus/Gutta-percha, Resilon/RealSeal self-etch (SE), and Endofill/Gutta-percha. Subjects and Methods: In this study, sixty, single-rooted mandibular premolars were used. The teeth chosen were de-coronated with a diamond disc and the root length was 14 mm for each specimen. All teeth were enlarged up to ISO size 30 master apical file using Ni–Ti rotary Protaper system and crown-down technique. Instrumented teeth were then randomly assigned into four experimental groups (n = 15) as follows: Group 1 - obturated with AH plus/Gutta-percha, Group 2 - obturated with Resilon/RealSeal SE, Group 3 - obturated with Endofill/Gutta-percha, and Group 4 - no obturation was done (control). The specimens were embedded into auto-polymerizing resin, later mounted in the universal testing machine and were subjected to load at a crosshead speed of 1.0 mm/min until the root fractured. Statistical Analysis Used: ANOVA and Duncan post hoc analysis. Results: Results of this in vitro study showed that Resilon/RealSeal SE showed better fracture resistance of all the materials tested. Statistically significant difference between the groups ( Conclusions: Resilon/RealSeal SE demonstrated higher fracture resistance values than AH plus/Gutta-percha, followed by Endofill/Gutta-percha